FUSIDIC ACID, 6990-06-3

2-[(1S,2S,5R,6S,7S,10S,11S,13S,14Z,15R,17R)-13-(acetyloxy)-5,17-dihydroxy-2,6,10,11-tetramethyltetracyclo[8.7.0.0^2,7.0^11,15]heptadecan-14-ylidene]-6-methylhept-5-enoic acid

Taksta (CEM-102)
Clinical-stage pharmaceutical firm Cempra has secured orphan drug status from the US Food and Drug Administration (FDA) for its drug candidate Taksta (CEM-102) to treat patients with prosthetic joint infections (PJI).

Cempra’s Taksta secures FDA orphan drug status for prosthetic joint infections treatment

http://www.pharmaceutical-technology.com/news/newscempras-taksta-secures-fda-orphan-drug-status-prosthetic-joint-infections-treatment?WT.mc_id=DN_News

TAKSTA^TM (CEM-102)

Fusidic acid is a bacteriostatic antibiotic that is often used topically in creams and eyedrops, but may also be given systemically as tablets or injections. The global problem of advancing antimicrobial resistance has led to a renewed interest in its use recently.

Fusidic acid acts as a bacterial protein synthesis inhibitor by preventing the turnover ofelongation factor G (EF-G) from the ribosome. Fusidic acid is effective primarily ongram-positive bacteria such as Staphylococcus species, Streptococcus species, and Corynebacterium species. Fusidic acid inhibits bacterial replication and does not kill the bacteria, and is therefore termed bacteriostatic.

Fusidic acid is a true antibiotic, derived from the fungus Fusidium coccineum and was developed by Leo Laboratories in Ballerup, Denmark and released for clinical use in the 1960s. It has also been isolated from Mucor ramannianus and Isaria kogana. The drug is licensed for use as its sodium salt sodium fusidate, and it is approved for use under prescription in South Korea, Japan, UK, Canada, Europe, Australia, New Zealand, Thailand, India and Taiwan. A different oral dosing regimen, based on the compound’s Pharmacokinetic/pharmacodynamic (PK-PD) profile is in clinical development in the U.S. as Taksta.

Fusidic acid (TAKSTA^TM, CEM-102) is an antibiotic with a long history of safety and efficacy outside the United States. Cempra has exclusive rights to the supply of the compound for the U.S. market. Fusidic acid is orally active against gram-positive bacteria, including all S. aureus strains such as HA-MRSA and CA-MRSA. A novel dosing regimen has been successfully evaluated in a Phase II trial in patients with acute bacterial skin and skin structure infections (aBSSSI). Cempra is conducting a Phase II trial of TAKSTA for patients with prosthetic joint infections.

Profile of TAKSTA (CEM-102)
Prosthetic joint infections (PJI) occur in about 1% of hip replacements and 2% of knee replacements, translating to an incidence rate of about 10,000 per year in the U.S. at current hip and knee arthroplasty rates.  There are few good options to treat these serious staphylococcal, often MRSA infections, which require long-term antibiotic treatment.  Current therapy in the U.S. is with intravenous antibiotics such as vancomycin.  An oral drug that can be safely administered for a long period of time could improve care and quality of life for these patients.

TAKSTA has shown potent activity against a large number of S. aureus strains, including CA-MRSA, HA-MRSA and linezolid-resistant strains, isolated in the U.S over a 10 year period. Its broad S. aureus coverage makes it useful for a broad range of clinical applications. Because of its safety and tolerability profile, TAKSTA could be ideal for patients suffering from staphylococcal infections that require long-term therapy such as patients with PJIs.

Cempra has developed a unique oral loading dose regimen to optimize key pathogen coverage and minimize drug resistance development. This regimen is incorporated in our Phase II trial to treat PJIs with TAKSTA in combination with rifampin, which is commonly used with injectible antibiotics such as vancomycin to treat PJIs.

Research on TAKSTA

Publications

The links for the articles go to subscription-based sites and may require a fee to view the article.

In Vitro Activity of CEM-102 (Fusidic Acid) Against Prevalent Clones and Resistant Phenotypes of Staphylococcus aureus 
DF Sahm, J Deane, CM Pillar, P Fernandes
Antimicrobial Agents and Chemotherapy. June 2013  57: 4535-4346
http://aac.asm.org/content/57/9/4535

Efforts to Support the Development of Fusidic Acid in the United States
P Fernandes, D Pereira
Clinical Infectious Disease. June 2011 52:S542-6
http://www.ncbi.nlm.nih.gov/pubmed/21546632

Case report: Treatment of Chronic Osteomyelitis 
CR Wolfe
Clinical Infectious Disease. June 2011 52:S538-41
http://cid.oxfordjournals.org/content/52/suppl_7/S538.long

The Safety Record of Fusidic Acid in Non-US markets: A Focus on Skin Infections
CN Kraus, BW Burnstead
Clinical Infectious Disease. June 2011 52:S527-37
http://cid.oxfordjournals.org/content/52/suppl_7/S527.long

A Randomized, Double-Blind Phase 2 Study Comparing the Efficacy and Safety of an Oral Fusidic Acid Loading-Dose Regimen to Oral Linezolid in the Treatment of Acute Bacterial Skin and Skin Structure Infections 
JC Craft, SR Moriarty, K Clark, D Scott, TP Degenhardt, JG Still, GR Corey, A Das,  P Fernandes
Clinical Infectious Disease. June 2011 52:S520-26
http://cid.oxfordjournals.org/content/52/suppl_7/S520.long

Application of Pharmacokinetic-Pharmacodynamic Modeling and the Justification of a Novel Fusidic Acid Dosing Regimen: Raising Lazarus from the Dead 
BT Tsuji, OO Okusanya, JB Bulitta, A Forrest, SM Bhavnani, P Fernandes, PG Ambrose
Clinical Infectious Disease. June 2011 52:S513-19
http://cid.oxfordjournals.org/content/52/suppl_7/S513.long

Pharmacokinetics and Safety of Single, Multiple, and Loading Doses of Fusidic Acid in Healthy Subjects 
JG Still,  K Clark, TP Degenhardt, D. Scott, P. Fernandes,  M. J. Gutierrez
Clinical Infectious Disease. June 2011 52:S504-12
http://cid.oxfordjournals.org/content/52/suppl_7/S504.long

Activity of Fusidic Acid Against Extracellular and Intracellular Staphylococcus aureus: Influence of pH and Comparison with Linezolid and Clindamycin
S Lemaire,  F Van Bambeke, D Pierard, PC Appelbaum,  PM Tulkens
Clinical Infectious Disease. June 2011 52:S493-503
http://cid.oxfordjournals.org/content/52/suppl_7/S493.long

Characterization of Global Patterns and the Genetics of Fusidic Acid Resistance 
DJ Farrell, M Castanheira, I Chopra
Clinical Infectious Disease. June 2011  52:S487-92
http://cid.oxfordjournals.org/content/52/suppl_7/S493.long

In Vitro Antimicrobial Findings for Fusidic Acid Tested Against Contemporary (2008-2009) Gram-Positive Organisms Collected in the United States
RN Jones, RE Mendes, HS Sader, M Castanheira
Clinical Infectious Disease. June 2011 52:S477-86
http://cid.oxfordjournals.org/content/52/suppl_7/S477.long

New Rules for Clinical Trials in Patients with Acute Bacterial Skin and Skin Structure Iinfections: Do not Let the Perfect be the Enemy of the Good 
GR Corey, ME Stryjewski
Clinical Infectious Disease. June 2011 52:S469-76
http://cid.oxfordjournals.org/content/52/suppl_7/S469.long

Introduction: Fusidic Acid Enters the United States
RC Moellering,  GR Corey, ML Grayson
Clinical Infectious Disease. June 2011 52:S467-8
http://cid.oxfordjournals.org/content/52/suppl_7/S467.long

Evaluation of the Pharmacokinetics-Pharmacodynamics of Fusidic Acid Against Staphylococcus aureus and Streptococcus pyogenes Using In Vitro Infection Models: Implications for Dose Selection 
OO Okusanya, BT Tsuji, JB Bulitta, A Forrest, CC Bulik, SM Bhavnani, P Fernandes, PG Ambrose
Diagnostic Microbiology & Infectious Disease. June 2011 70:101-11
http://www.ncbi.nlm.nih.gov/pubmed/21513848

In Vitro Activity of Fusidic Acid (CEM-102, Sodium Fusidate) Against Staphylococcus aureus Isolated from Cystic Fibrosis Patients and its Effect on the Activities of Tobramycin and Amikacin against Pseudomonas aeruginosa and Burkholderia cepacia 
P McGhee, K Credito, L Beachel, PC Appelbaum,  K Kosowaska-Shick
Antimicrobial Agents and Chemotherapy. June 2011 55:2417-19
http://www.ncbi.nlm.nih.gov/pubmed/21513848

Occurrence and Molecular Characterization of Fusidic Acid Resistance Mechanisms Among Staphylococcus spp. From European Countries (2008)
Castanheira, M., AA Watters, RE Mendes, DJ Farrell, RN Jones
Antimicrobial Agents and Chemotherapy. April 2010 65:1353-8
http://jac.oxfordjournals.org/content/65/7/1353.long

Update on Fusidic Acid (CEM-102) Tested Against Neisseria gonorrhoeae and Chlamydia trachomatis
R Jones, D Biedenbach, P Roblin, S Kohlhoff, M Hammerschlag
Antimicrobial Agents and Chemotherapy. October 2010 54: 4518-4519
http://aac.asm.org/cgi/content/citation/54/10/4518

Fusidic Acid Resistance Rates and Prevalence of Resistance Mechanisms Among Staphylococcus spp. Isolated in North America and Australia, 2007-2008
M Castanheira, AA Watters, JM Bell, JD Turnidge, RN Jones
Antimicrobial Agents and Chemotherapy. September 2010 54: 3614-3617
http://www.ncbi.nlm.nih.gov/pubmed/20566766

Spectrum of Activity, Mutation Rates, Synergistic Interactions, and the Effects of pH and Serum Proteins for Fusidic Acid (CEM-102)
D Biedenbach, P Rhomberg, R Mendes, R Jones
Diagnostic Microbiology & Infectious Disease. March 2010 66: 301-307
http://www.dmidjournal.com/article/S0732-8893(09)00424-6/abstract

Performance of Fusidic Acid (CEM-102) Susceptibility Testing Reagents: Broth Microdilution, Disk Diffusion, and Etest Methods as Applied to Staphylococcus aureus
R Jones, M Castanheira, P Rhomberg, L Woosley, M Pfaller
Journal of Clinical Microbiology. March 2010 48: 972-976
http://jcm.asm.org/cgi/content/abstract/48/3/972

Evaluation of the Activity of Fusidic Acid Tested Against Contemporary Gram-Positive Clinical Isolates From the USA and Canada
M Pfaller, M Castaneira, H Sader, R Jones
International Journal of Antimicrobial Agents. March 2010 35: 282-287
http://www.ijaaonline.com/article/S0924-8579(09)00510-X/abstract

NEW YORK, November 04, 2013–(BUSINESS WIRE)–Pfizer Inc. (NYSE: PFE) announced today that the U.S. Food and Drug Administration (FDA) has approved a Prior Approval Supplement for EMBEDA® (morphine sulfate and naltrexone hydrochloride) Extended Release Capsules CII.

The Prior Approval Supplement included an update to the EMBEDA manufacturing process that addressed the pre-specified stability requirement that led to the voluntary recall of EMBEDA from the market in March 2011. Pfizer anticipates product availability in the second quarter of 2014.

http://www.pharmalive.com/fda-oks-prior-approval-supplement-for-embeda

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Macimorelin

CAS  381231-18-1

Chemical Formula: C26H30N6O3

Exact Mass: 474.23794

Molecular Weight: 474.55480

Elemental Analysis: C, 65.80; H, 6.37; N, 17.71; O, 10.11

945212-59-9 (Macimorelin acetate)

USAN (ab-26)
MACIMORELIN ACETATE

THERAPEUTIC CLAIM
Diagnostic agent for adult growth hormone deficiency (AGHD)
CHEMICAL NAMES
1. D-Tryptophanamide, 2-methylalanyl-N-[(1R)-1-(formylamino)-2-(1H-indol-3-yl)ethyl]-, acetate (1:1)
2. N2-(2-amino-2-methylpropanoyl-N1-[(1R)-1-formamido-2-(1H-indol-3-yl)ethyl]- D-tryptophanamide acetate

MOLECULAR FORMULA
C26H30N6O3.C2H4O2
MOLECULAR WEIGHT
534.6

SPONSOR
Aeterna Zentaris GmbH
CODE DESIGNATIONS
D-87575, EP 1572, ARD 07
CAS REGISTRY NUMBER
945212-59-9

Macimorelin (also known as AEZS-130, EP-1572) is a novel synthetic small molecule, acting as a ghrelin agonist, that is orally active and stimulates the secretion of growth hormone (GH). Based on results of Phase 1 studies, AEZS-130 has potential applications for the treatment of cachexia, a condition frequently associated with severe chronic diseases such as cancer, chronic obstructive pulmonary disease and AIDS. In addition to the therapeutic application, a Phase 3 trial with AEZS-130 as a diagnostic test for growth hormone deficiencies in adults has been completed.

http://www.ama-assn.org/resources/doc/usan/macimorelin-acetate.pdf

QUEBEC, Nov. 5, 2013 /PRNewswire/ – Aeterna Zentaris Inc. (the “Company”) today announced that it has submitted a New Drug Application (“NDA”) to the U.S. Food and Drug Administration (“FDA”) for its ghrelin agonist, macimorelin acetate (AEZS-130). Phase 3 data have demonstrated that the compound has the potential to become the first orally-approved product that induces growth hormone release to evaluate adult growth hormone deficiency (“AGHD”), with accuracy comparable to available intravenous and intramuscular testing procedures.  read at

http://www.drugs.com/nda/macimorelin_acetate_131105.html

http://www.ama-assn.org/resources/doc/usan/macimorelin-acetate.pdf

macimorelin (JMV 1843), a ghrelin-mimetic growth hormone secretagogue in Phase III for adult growth hormone deficiency (AGHD)

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DR ANTHONY MELVIN CRASTO Ph.D

amcrasto@gmail.com

Quetiapine, astrazeneca

111974-69-7 cas

US 5,948,437*PED,   NDA 022047   Appr may 17 2007 sustained release  formulation

NDA 020639 approved 26.9.1997

patent          approved   expiry

Quetiapine (/kwɨˈtaɪ.əpiːn/ kwi-ty-ə-peen) (branded as Seroquel, Xeroquel, Ketipinor) is a short-acting atypical antipsychotic approved for the treatment of schizophrenia, bipolar disorder, and along with an antidepressant to treat major depressive disorder.

Annual sales are approximately $5.7 billion worldwide, with $2.9 billion in the United States. The U.S. patent, which  expiredv in 2011, received a pediatric exclusivity extension which pushed its expiration to March 26, 2012.The patent has already expired in Canada. Quetiapine was developed by AstraZeneca from 1992-1996 as an improvement from first generation antipsychotics. It was first approved by the FDA in 1997. There are now several generic versions of quetiapine, such as Quepin, Syquel and Ketipinor

Seroquel (quetiapine) is a psychotropic medication that is used to treat schizophrenia in adults and children who are at least 13 years old. Seroquel is also used in the treatment of major depression and bipolar disorder. Side effects of Seroquel may include mood or behavior changes, constipation, drowsiness, headache, and trouble sleeping. Older adults with dementia may have a slightly increased risk of death when taking this medication.

Dosing preparations are 25, 50, 100, 200, 300, and 400 mg tablets. Seroquel may interact with a number of other drugs, including, but not limited to, antidepressant medications, antifungal drugs, steroids, cimetidine (Tagamet), thioridazine (Mellaril), and lorazepam (Ativan). During pregnancy, this medication should be used only when clearly needed. Discuss the risks and benefits with your doctor. Seroquel passes into breast milk and may have undesirable effects on a nursing infant.

Quetiapine fumarate is a psychotropic agent belonging to a chemical class of dibenzothiazepine derivatives, designated chemically as 2-[2-(4-dibenzo [b,f] [l,4]thiazepin -1 l-yl-l-piperazinyl)ethoxy]-ethanol fumarate (2: l )(salt). Its molecular formula is C42H5oN₆0₄S₂*C₄H₄0₄ having a molecular weight of 883.1 1. The structural formula is:

Quetiapine is marketed as immediate release as well as extended release tablets in United States under the trade name Seroquel® and Seroquel XR® by AstraZeneca.

• Quetiapine was first described in a patent publication EP 240228 (US 4879288 ). It is prepared starting from dibenzo[b,f][1,4]thiazepin-11-[10H]one of formula II

  which is first halogenated with phosphorous oxychloride, then isolated and condensed with 1-(2-hydroxyethoxy) ethyl piperazine to obtainquetiapine. After purification by flash chromatography the yield was 77.7 %. As an alternative to halogenation a process via a thioether in the first step is presented.

• In the process claimed in EP 282236 the piperazine ring is first condensed with 11-chloro-dibenzo[b,f][1,4] thiazepine and thereafterquetiapine is obtained by its reaction with haloethoxy ethanol. The base is further converted to the hemifumarate salt, which was isolated in 78 % yield.
• WO 2006/117700 describes a process of EP ’228 improved by the destruction of phosphorous oxychloride in situ to decrease the amount of hazardous waste. Phosphorous oxychloride is used only about 1 equivalent to the compound of formula II whereas in the process of EP 240228 it was used in about 15 equivalents.
• A reaction of 11-chlorodibenzo[b,f][1,4]thiazepine with a piperazine moiety in the presence of a halide is the improvement described inWO 2006/113425 . The process is said to yield quetiapine in high purity.
• In WO 2006/094549 there is described a process which avoids the halogenation step and the use of hazardous phosphorous halogenating agents by the reaction of 10H-dibenzo[b,f][1,4] thiazepin-11-one directly with a piperazine derivative. This is achieved by performing the reaction in the presence of titanium alkoxide. Yields of 50 – 75 % as a fumarate salt are reported. Expensive titanium alkoxide is used from about 2 to 3 fold excess to starting compound of formula II.
• Also the process of US 2006/0063927 avoids the use of phosphorous compounds in halogenation by using oxalyl chloride as a halogenating agent. The imino chloride is obtained in 66 % yield. The reaction of 11-chloro-dibenzo[b,f][1,4] thiazepine with 1-(2-hydroxyethoxy)ethylpiperazine is performed either in the presence of a base in an organic solvent or in a two-phase system. However, the reagent used, oxalyl chloride is poisonous and requires special attention.
• A one-pot process for the preparation of quetiapine is described inWO 2007/020011 . Phosphorous oxychloride is used in halogenation step about one equivalent to 10H-dibenzo[b,f][1,4] thiazepin-11-one.
• WO 2007/004234 describes a process comprising the reaction of chloro ethoxy ethanol with piperazinyl-dibenzo[b,f][1,4] thiazepine dihydrocloride, which is obtained by halogenating the dibenzo[b,f][1,4] thiazepin-11-[10H]one, reacting the imino chloride obtained with piperazine, and treating the obtained compound with an alcoholic solution of hydrogen chloride.
• All processes described above use dibenzo[b,f][1,4] thiazepin-11-[10H]one as a starting material. Its preparation requires several steps, and in most cases it has to be even halogenated to the imino chloride before the piperazine moiety can be condensed with it. Halogenating reagents, e.g. phosphorous oxychloride have been used in excess and their removal from the reaction mixture requires evaporation of large amounts.
• A different approach using protected intermediates is used e.g. in routes described in WO 2005/014590 , WO 2005/028457 , WO 2005/028458and WO 2005/028459 . In some cases the reactions may be performed in one pot fashion and no extra purification steps are needed to get a pure product in high yield. However, protection and deprotection steps used lengthen the processes and shorter processes for the preparation of quetiapine are still needed.
• Similar compounds are prepared in US 3, 539,573

U.S. Patent 4,879,288 discloses 1 l-[4-[2-(2-hydroxyethoxy) ethyl] -1 – piperazinyl] dibenzo [b, f] [1 , 4] thiazepine as an antipsychotic drug of dibenzothiazepine class suitable for treatment of various psychotic disorders.

US patent 5,948,437 discloses sustained release formulations of quetiapine using gelling agents such as hydroxypropyl methylcellulose and its derivatives that create a gel structure after contact with water. US patent 4,547,57 1 describes process for the preparation of carboxymethyl ethyl cellulose (CMEC) polymer.

WO 2004012699 discloses modified release dosage forms prepared by using dual – retard— technique comprising micro matrix particles containing quetiapine and hydrophobic release controlling agents, which are coated with hydrophobic release controlling agents.

WO 2005041935 discloses matrix composition comprising quetiapine and a wax material.

WO 2007086079 discloses sustained release compositions of quetiapinecomprising a channelizer and a rate controlling polymer.

WO 2008060228 discloses extended release compositions comprisingquetiapine, hydroxypropyl methyl cellulose and sodium citrate dihydrate.

WO 20091 13051 discloses sustained release compositions containingquetiapine and one or more non-gelling and/or waxy excipients.

WO 2010001413 discloses sustained release dosage forms comprisingquetiapine or its pharmaceutically acceptable salts and one or more non-gellable release controlling polymers.

WO 2010028794 discloses a matrix formulation in the form of a retard tablet comprising quetiapine, at least one matrix-forming, water-insoluble, non-swellable auxiliary agent, and at least one water-soluble binding agent.

The synthesis of quetiapine begins with a dibenzothiazepinone. The lactam is first treated with phosphoryl chloride to produce a dibenzothiazepine. A nucleophilic substitutionis used to introduce the sidechain.U.S. Patent 4,879,288.

Atypical antipsychotic quetiapine (Quetiapine, drugs used its fumarate) for the treatment of schizophrenia (schizophrenia) and dry depressive disorder (bipolar disorder), trade name Seroquel, produced by AstraZeneca. Star molecule drugs, the global sales of about $ 6 billion.

Quetiapine synthesis o-nitro-chlorobenzene ( 1 ) starting a thiophenol occurred and SNAr reaction, hydrogenation of nitro group to an amino group after reaction with phosgene isocyanate 2 , 2 ring closure in hot sulfuric acid to obtain 3 , 3 with phosphorus oxychloride isomerization chlorinated4 , 4 and 5 SNAr reaction occurs fumarate salt formation with quetiapine fumarate.

The route of the compound 4 is not stable enough, then there are improved route. 6 and the reaction of phenyl chloroformate 7

Quetiapine fumarate, Bis [2-(2-[4-(dibenzo[b,f][1,4]thiazepin-11-yl]ethoxy)ethanol] fumarate (IUPAC)2-[2-(4-dibenzo[b,f][1,4]thiazepin-11-yl-1-piperazinyl)ethoxy]-ethanol-(E)-2-butanedioate (2:1) salt), [ICI 204,636], is a novel dibenzothiazepine antipsychotic developed by Zeneca. It is marketed under the trade name ‘Seroquel’Seroquel. Quetiapine is well tolerated and clinically effective in the treatment of schizophrenia.

The initial hope of investigators was that quetiapine would have antipsychotic potential and that it might share some of the properties of clozapine without its toxicity to white blood cells.

The effective dosage range is usually 300-450 mg/day split into two doses. The dose is titrated upwards from 25 mg twice dailybd from day one to 300mg/daya fuller dosage on day 4. Elderly patients or patients with liver problems should be started on lower doses. It is both superior to placebo and, and comparable to haloperidol in reducing positive symptoms at doses ranging from 150 to 750 mg/day and is an effective treatment for in reducing negative symptoms at a dose of 300 mg/day.

Somnolence is the most common adverse event. Abnormalities of the QTqt interval on ECG appear very infrequently and there is no need for a baseline ECG or blood pressure monitoring as used to be the case with ssertindole. There is no need for haematological monitoring as with clozapine. Quetiapine, across the full dosage range, is associated with no greater extrapyramidal symptoms than placeboThere is a reduced potential for extrapyramidal symptoms compared with conventional antipsychotics.

Quetiapine’s general efficacy and side effect profile suggest that, unless there are unforeseen post-marketing complications, quetiapine deserves a major place in the initial and long term management of schizophreniform disorders.

Quetiapine fumarate, Bis [2-(2-[4-(dibenzo[b,f][1,4]thiazepin-11-yl]ethoxy)ethanol] fumarate (IUPAC) 2-[2-(4-dibenzo[b,f][1,4]thiazepin-11-yl-1-piperazinyl)ethoxy]-ethanol-(E)-2-butanedioate (2:1) salt), [ICI 204,636], is a novel dibenzothiazepine antipsychotic developed by Zeneca Pharmaceuticals. It is marketed under the trade name ‘Seroquel’. Quetiapine is well tolerated and clinically effective in the treatment of schizophrenia.

Eslicarbazepine acetate, 236395-14-5 cas no

(S)-10-Acetoxy- 10,11-dihydro- 5H-dibenz[b,f]azepine- 5-carboxamide
Sunovion Pharmaceuticals Inc. A US-based subsidiary of Japanese drugmaker Dainippon Sumitomo Pharma Announces FDA Approval of Aptiom® (eslicarbazepine acetate) as Once-Daily Adjunctive Treatment of Partial-Onset Seizures
MONDAY Nov. 11, 2013 — Aptiom (eslicarbazepine acetate) has been approved by the U.S. Food and Drug Administration as an add-on drug to help treat adults with partial epileptic seizures.

Epilepsy, caused by abnormal activity in the brain’s nerve cells, is diagnosed in some 200,000 people annually in the United States, the agency said in a news release. So-called “partial” seizures are the most common type of seizure among people with epilepsy, triggering possible symptoms including repetitive movement of limbs, unusual behavior and convulsions.http://www.drugs.com/news/aptiom-approved-seizures-48845.html

The FDA has determined that APTIOM will not be classified as a controlled substance. Sunovion expects APTIOM to be available in U.S. pharmacies in the second quarter (April – June) of 2014

APTIOM, a voltage-gated sodium channel inhibitor, is a prescription medicine approved for use as adjunctive treatment of partial-onset seizures. Treatment with APTIOM should be initiated at 400 mg once daily. After one week, dosage may be increased to the recommended maintenance dosage of 800 mg once daily. Some patients may benefit from the maximum recommended maintenance dosage of 1,200 mg once daily, although this dosage is associated with an increase in adverse reactions. The maximum dose of 1,200 mg daily should only be initiated after the patient has tolerated 800 mg daily for at least a week. For some patients, treatment may be initiated at 800 mg once daily if the need for additional seizure reduction outweighs an increased risk of adverse reactions during initiation.

The initial research and development of eslicarbazepine acetate was performed by BIAL, a privately held Portuguese research-based pharmaceutical company. Subsequently, Sunovion acquired the rights under an exclusive license to further develop and commercialize eslicarbazepine acetate in the U.S. and Canadian markets from BIAL. In February 2009, Eisai Europe Limited, a European subsidiary of Eisai Co., Ltd. (Eisai), entered into a license and co-promotion agreement with BIAL, which gave the rights to Eisai to sell eslicarbazepine acetate under the trade name Zebinix^® in Europe. Zebinix was approved by the European Commission on April 21, 2009 as adjunctive therapy in adult patients with partial-onset seizures with or without secondary generalization and is currently marketed in Europe under the agreement.

Eslicarbazepine acetate (BIA 2-093) is an antiepileptic drug. It is a prodrug which is activated to eslicarbazepine (S-licarbazepine), an active metabolite of oxcarbazepine.^[1]

It is being developed by Bial^[2] and will be marketed as Zebinix or Exalief by Eisai Co. in Europe and as Stedesa by Sepracor^[3] in America.

The European Medicines Agency (EMA) has recommended granting marketing authorization in 2009 for adjunctive therapy for partial-onset seizures, with or without secondary generalisation, in adults with epilepsy.^[1] The U.S. Food and Drug Administration (FDA) announced on 2 June 2009 that the drug has been accepted for filing.^[3]

Eslicarbazepine acetate is a prodrug for S(+)-licarbazepine, the major active metabolite of oxcarbazepine.^[4] Its mechanism of action is therefore identical to that of oxcarbazepine. ^[5] There may, however, be pharmacokinetic differences. Eslicarbazepine acetate may not produce as high peak levels of (S)-(+)-licarbazepine immediately after dosing as does oxcarbazepine which could theoretically improve tolerability.

Like oxcarbazepine, eslicarbazepine may be used to treat bipolar disorder and trigeminal neuralgia.

The first European patent to protect this drug is EP 0751129 . The priority of this European patent is the Portuguese patent application PT 101732 .

1.  Dulsat, C., Mealy, N., Castaner, R., Bolos, J. (2009). “Eslicarbazepine acetate”. Drugs of the Future 34 (3): 189. doi:10.1358/dof.2009.034.03.1352675.
2.  Community register of medicinal products for human use: Exalief
3. Medical News Today: Sepracor’s STEDESA (Eslicarbazepine Acetate) New Drug Application Formally Accepted For Review By The FDA
4.  Rogawski, MA (Jun 2006). “Diverse Mechanisms of Antiepileptic Drugs in the Development Pipeline”. Epilepsy Res 69 (3): 273–294. doi:10.1016/j.eplepsyres.2006.02.004. PMC 1562526. PMID 16621450.
5.  Rogawski MA, Löscher W (July 2004). “The neurobiology of antiepileptic drugs”. Nature Reviews Neuroscience 5 (7): 553–64. doi:10.1038/nrn1430. PMID 15208697.
6. http://newdrugapprovals.wordpress.com/2013/03/11/sunovion-announces-fda-acceptance-for-review-of-new-drug-application-resubmission-for-stedesa-eslicarbazepine-acetate/

Eslicarbazepine acetate of Formula A, chemically known as (10S)-5-carbamoyl- 10,1 l-dihydro-5H-dibenzo[Z?,/]azepin- 10-yl acetate is indicated as adjunctive therapy in adults with partial-onset seizures with or without secondary generalisation.

Formula A

lO-oxo-10,1 l-dihydro-5H-dibenzo[Z?/]azepine-5-carboxamide of Formula 1, commonly known as oxcarbazepine, is an antiepileptic drug marketed under the trade name Trileptal^®and is indicated for use as monotherapy or adjunctive therapy in the treatment of partial seizures in adults and as monotherapy in the treatment of partial seizures in children aged 4 years and above with epilepsy, and as adjunctive therapy in children aged 2 years and above with epilepsy. Oxcarbazepine is an intermediate for the preparation of eslicarbazepine.

Formula 1

Several processes are known in the literature for making and purifying eslicarbazepine acetate, for example, U.S. Patent No 5,753,646; and PCT Publications WO 2006/005951 ; WO 2007/1 17166; and WO 2010/1 13179.

U.S. Patent No. 5,753,646 provides a process for the preparation of eslicarbazepine acetate which involves adding dropwise a solution of acetyl chloride in dichloromethane to a suspension of (-)- 10-hydroxy-10,l l-dihydro-5H-dibenz/b,f/azepine-5-carboxamide in dichloromethane and pyridine at a temperature of less than 10°C under stirring. The residue obtained after workup was crystallized from a mixture of dichloromethane and ethyl acetate to give the eslicarbazepine acetate as white crystals.

U.S Publication No. 2009/0203902 provides preparation of eslicarbazepine acetate which involves the acylation of (S)-(+)-10,l l-dihydro-10-hydroxy-5H-dibenz/b,f/azepine- 5-carboxamide with acetic anhydride in presence of 4-(N,N-dimethylamino)pyridine and pyridine in dichloromethane at reflux temperature. The resulting solid obtained after work-up was slurried with isopropanol at reflux to obtain a solution. The solution was cooled to 1°C to 5°C and eslicarbazepine acetate was isolated from the reaction mass by filtration followed by washing with isopropanol.

PCT Publication No. WO 2010/1 13179 provides various purification methods of eslicarbazepine acetate which involve the use of acetonitrile/methyl tertiary butyl ether, tetrahydrofuran/n-hexane, tetrahydrofuran/methyl tertiary butyl methyl ether;

tetrahydrofuran, methyl ethyl ketone/n-hexane.

Several processes are known in the literature for making oxcarbazepine, for example, U.S. Patent Nos. 4,452,738 and 7,459,553; PCT Publication Nos. WO

2010/000196; WO 2008/012837; WO 2007/141798; WO 2006/075925; WO 2005/122671 ; WO 2005/1 18550; WO 2005/096709; WO 2005/092862; WO

2005/066133; WO 02/096881 ; WO 00/55138; and WO 96/21649.

PCT Publication No. WO 02/096881 provides a process for the preparation of oxcarbazepine which involves oxidation of 10,1 1 -dihydro- 10-hydroxy-5H- dibenz/b,f/azepine-5-carboxamide with peroxyacetic acid in presence of potassium dichromate adsorbed on silica gel at room temperature.

Japanese Patent Publication No. JP 2004- 175761 provides a process for the preparation of oxcarbazepine which involves oxidation of 10, 1 1 -dihydro- 10-hydroxy-5H- dibenzo[b,f]azepine-5-carboxamide with dimethyl sulfoxide and an activator such as sulfur trioxide-pyridine complex.

Chinese Publication No. CN 101302198 provides a process for the preparation of oxcarbazepine which involves oxidation of 10-hydroxy- 10, l 1 -dihydro-5H- dibenzo[Z?/]azepine-5-carbonitrile with TEMPO and sodium hypochlorite to provide 10- oxo- 10,1 l-dihydro-5H-dibenzo[Z?/]azepine-5-carbonitrile which was further hydrolysed with sulfuric acid to obtain oxcarbazepine.

• Eslicarbazepine acetate, (S)-(-)-10-acetoxy-10,11-dihydro-5H-dibenz/b,f/azepine-5-carboxamide (“BIA 2-093″), is a new drug currently being developed which is useful for the treatment of various conditions, such as, for example, epilepsy and affective brain disorders, as well as pain conditions and nervous function alterations in degenerative and post-ischemic diseases. Although chemically related to carbamazepine and oxcarbazepine, eslicarbazepine acetate is believed to avoid the production of certain toxic metabolites (such as, for example, epoxides) and to avoid the unnecessary production of enantiomers or diastereoisomers of metabolites and conjugates, without losing pharmacological activity. See Benes et al., “Anticonvulsant and Sodium Channel-Blocking Properties of Novel 10,11-Dihydro-5H-dibenz[b,f]azepine-5-carboxamide Derivatives,” J. Med. Chem., 42, 2582-2587 (1999).
• Like carbamazepine and oxcarbazepine, eslicarbazepine acetate is believed to be a voltage-gated sodium channel (VGSC) blocker that competitively interacts with site 2 of the inactivated state of the sodium channel. The affinity for this state of the channel is similar to that of carbamazepine, while the affinity for the resting state of the channel is about 3-fold lower than that of carbamazepine. This profile may suggest an enhanced inhibitory selectivity of eslicarbazepine acetate for rapidly firing neurons over those displaying normal activity. See Bonifacio et al., “Interaction of the Novel Anticonvulsant, BIA 2-093, with Voltage-Gated Sodium Channels: Comparison with Carbamazepine,” Epilepsia, 42, 600-608(2001).
• Evaluation of the metabolic profile of eslicarbazepine acetate, following chiral analysis, in liver microsomes from rats, dogs, monkeys and humans was found to give the S(+) enantiomer of licarbazepine, (S)-(+)-10,11-dihydro-10-hydroxy-5H dibenz/b,f/azepine-5-carboxamide (also known as “eslicarbazepine”), and not the R(-) form of licarbazepine, (R)-(-)-10,11-dihydro-10-hydroxy-5H dibenz/b,f/azepine-5-carboxamide (also known as “R-licarbazepine”).
• Studies in humans have shown that, after oral administration, eslicarbazepine acetate appears to be rapidly and extensively metabolized to the active metabolite eslicarbazepine and, in a minor extent, to R-licarbazepine. See Silveira et al., “BIA 2-093 Pharmacokinetics in Healthy Elderly Subjects,” Epilepsia, 45 (suppl. 3), 157 (2004). For example, the plasma concentrations of the parent drug (eslicarbazepine acetate) have been systematically found below the limit of quantification (LOQ) of the assay (10 ng/mL). See Almeida I; Almeida, L. & Soares-da-Silva, P., “Safety, Tolerability and Pharmacokinetic Profile of BIA 2-093, a Novel Putative Antiepileptic Agent, during First Administration to Humans,” Drugs R&D, 4, 269-284 (2003) (herein referred to as “Almeida II“). When a non-chiral method is used, the assay does not distinguish between eslicarbazepine and the R-enantiomer, and the mixture was reported as “BIA 2-005″ or “racemic licarbazepine.”
• The inventors performed entry-into-man studies in healthy subjects, the results of which they described in the Almeida I and Almeida II articles, both of which are hereby incorporated by reference. In these studies, the healthy subjects received a single oral dose of eslicarbazepine acetate wherein the dose ranged from 20 mg to 1200 mg (see Almeida II), and multiple daily-doses of eslicarbazepine acetate ranging from 200 mg twice-daily to 1200 mg once-daily (see Almeida I). Further studies (not yet published) by the inventors have investigated higher doses of eslicarbazepine acetate, including, for example, doses ranging up to 2400 mg once-daily. The studies showed that BIA 2-005 maximum observed plasma concentration (C_max) was attained at about 1 hour to about 4 hours post-dose (t_max), the extent of systemic exposure to BIA 2-005 was approximately dose-proportional, and steady-state of BIA 2-005 plasma concentrations was attained at about 4 to 5 days. The mean renal clearance of BIA 2-005 from plasma was about 20-30 mL/min, and the total amount of BIA 2-005 recovered in the urine was approximately 20% and 40% within 12 hours and 24 hours post-dose, respectively.
• The studies also showed that the apparent terminal half-life of BIA 2-005 ranged from about 8 hours to about 17 hours. See, e.g., Almeida II.
• U.S. Patent No. 6,296,873 discloses a sustained release delivery system for carbamazepine, which has a half-life ranging from 25 hours to 85 hours. To avoid adverse effects, U.S. Patent No. 6,296,873 teaches that the carbamazepine should be administered in tablet form up to two or more times daily to slowly release the compound to maintain concentration levels between 4-12 µg/mL. Such a delivery system requires a form that is capable of delivering the compound over an extended period of time, such as a tablet form.

 

 

 

 

 

http://www.sciencedirect.com/science/article/pii/S0040403913005030

ESLICARBAZEPINE ACETATE

Physiochemical Pr operties:

Molecular weight	:	296.32
Category	:	Anti-epileptic
Molecular formula	:	C17H16N2O5
Chemical Name	:	(S)-(-)-10-acetoxy-10,11-dihydro-5H-dibenz [b, f]
		azepine-5-carboxamide.
Description	:	White to off-White, odourless, non-hygroscopic,
		crystalline powder.
Solubility	:	Freely soluble in dichloromethane, sparingly soluble
		in acetone, acetonitrile, methanol, tetrahydrofuran and
		slightly soluble in ethanol and 2-propanol, insoluble in
		water
Melting Point	:	184-187°C
Storage	:	Can be easily stored at temperatures up to 30°C

HPLC, NMR

NMR NUMBERING

http://www.sciencedirect.com/science/article/pii/S0731708511006753

TEVETEN® (eprosartan mesylate) is a non-biphenyl non-tetrazole angiotensin II receptor (AT1) antagonist. A selective non-peptide molecule, TEVETEN® is chemically described as the monomethanesulfonate of (E)-2-butyl-1 -(p-carboxybenzyl)-α-2-thienylmethylimid-azole-5 -acrylic acid.

Its empirical formula is C23H24N2O4S•CH4O3S and molecular weight is 520.625. Its structural formula is:

EPROSARTAN MESYLATE

tevetenEprosartan mesilate, SK&F-108566-J(?, SK&F-108566, Teveten SB, Navixen, Regulaten, Tevetenz, Teveten

US 5656650

exp Aug 12, 2014

Eprosartan is an angiotensin II receptor antagonist used for the treatment of high blood pressure. It is marketed as Teveten byAbbott Laboratories in the United States.It is marketed as Eprozar by INTAS Pharmaceuticals in India and by Abbott Laboratorieselsewhere. It is sometimes paired with hydrochlorothiazide, marketed in the US as Teveten HCT and elsewhere as TevetenPlus.

The drug acts on the renin-angiotensin system in two ways to decrease total peripheral resistance. First, it blocks the binding ofangiotensin II to AT₁ receptors in vascular smooth muscle, causing vascular dilatation. Second, it inhibits sympatheticnorepinephrine production, further reducing blood pressure.

As with other angiotensin II receptor antagonists, eprosartan is generally better tolerated than enalapril (an ACE inhibitor), especially among the elderly.^[1]

^{Eprosartan is an angiotensin II receptor antagonist used for the treatment of high blood pressure. It acts on the renin-angiotensin system in two ways to decrease total peripheral resistance. First, it blocks the binding of angiotensin II to AT1 receptors in vascular smooth muscle, causing vascular dilatation. Second, it inhibits sympathetic norepinephrine production, further reducing blood pressure.}

1.  Ruilope L, Jäger B, Prichard B (2001). “Eprosartan versus enalapril in elderly patients with hypertension: a double-blind, randomized trial”. Blood Press. 10 (4): 223–9. doi:10.1080/08037050152669747. PMID 11800061.

• Teveten website

PAT            APR                EXP

J Med Chem1991,34,(4):1514-7

J Med Chem1993,36,(13):1880-92

Synth Commun1993,23,(22):3231-48

AU 9056901, EP 403159, JP 91115278, US 5185351.

Drugs Fut1997,22,(10):1079

Eprosartan mesylate was developed successfully by SmithKline Beecham Corporation in 1997, and marketed in Germany in 1998 under the trade-name Teveten and in the United States later in 1999. Eprosartan mesylate, as an angiotensin II receptor blocker, is an antihypertensive drug of the latest generation. Eprosartan mesylate is potent to lower systolic and diastolic pressures in mild, moderate and severe hypertensive patients, and is safe and tolerable. Eprosartan mesylate is rapidly absorbed when administrated orally, with a bioavailability of 13% and a protein binding rate of 98%. The blood peak concentration and AUC (Area Under Curve) can be elevated by about 50% in patients with liver and kidney dysfunction, or fullness after administration, and can be elevated by 2 to 3 folds in elderly patients. Eprosartan mesylate has a structure shown as follows:

U.S. Pat. No. 5,185,351 discloses a method for preparing eprosartan mesylate using Eprosartan and methanesulfonic acid in isopropanol (U.S. Pat. No. 5,185,351, Example 41 (ii)). However, it is found when following this method for preparing eprosartan mesylate in industry, an esterification reaction can occur between eprosartan and isopropanol and the following two impurities can be generated:

In addition to the above two esterification impurities, the salifying method provided by the above patent is prone to produce isopropyl mesylate. Considering currently known potential risk of gene toxicity of methylsulfonic acid ester on human as well as the stringent requirements of methylsulfonic acid ester from the Europe and the America authorities, it is important to produce eprosartan mesylate in a non-alcohol solvent during the process of producing eprosartan mesylate, since it avoids the formation of methylsulfonic acid ester and the residue thereof in the final product. Since the dosage of eprosartan mesylate is high, it is particularly important to strictly control methylsulfonic acid ester in eprosartan mesylate.

In addition, for the above salifying method, solid eprosartan is suspended in propanol at a low temperature, then methanesulfonic acid is added, about ten seconds later a great deal of eprosartan mesylate precipitate is obtained. Therefore, solid eprosartan may be embedded by the precipitated eprosartan mesylate. Since isopropyl alcohol has a high viscosity at low temperature, a heavy filtering operation burden is needed to obtain solid from isopropanol, and the obtained solid contains quite an amount of isopropanol.

Eprosartan has been obtained by several different ways: 1) The iodination of 2-butylimidazole (I) with I2 and Na2CO3 in dioxane/water gives 2-butyl-4,5-diiodoimidazole (II), which is treated with benzyl chloromethyl ether (III) and K2CO3 in DMF yielding the imidazole derivative (IV). The condensation of (IV) with N-methyl-N-(2-pyridyl)formamide (V) by means of butyllithium in THF affords 1-(benzyloxymethyl)-2-butyl-4-iodoimidazole-5-carbaldehyde (VI), which is deprotected with concentrated HCl ethanol to give 2-butyl-4-iodoimidazole-5-carbaldehyde (VII). The acylation of (VII) with methyl 4-(bromomethyl)benzoate (VIII) by means of K2CO3 in hot DMF yields 4-(2-butyl-5-formyl-4-iodoimidazol-1 ylmethyl)benzoic acid methyl ester (IX), which is deiodinated by hydrogenation with H2 over Pd/C in methanol affording compound (X). The condensation of (X) with methyl 3-(2-thienyl)propionate (XI) by means of lithium diisopropylamide (LDA) in THF gives (XII), which is acylated with acetic anhydride and dimethylaminopyridine (DMAP) in dichloromethane yielding the corresponding acetate (XIII). Elimination of acetic acid from (XIII) with 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in hot toluene affords the expected propenoic ester (XIV), which is finally saponified with NaOH or KOH in ethanol/water.

…………………………………………………………………………………………………….

WO 1998035962 A1

…………………………………………………………………………………………..

Ziprasidone

Ziprasidone (marketed as Geodon, Zeldox by Pfizer) was the fifth atypical antipsychotic to gain approval (February 2001) in the United States. It is approved by the U.S. Food and Drug Administration (FDA) for the treatment of schizophrenia, and acute mania and mixed states associated withbipolar disorder. Its intramuscular injection form is approved for acute agitation in schizophrenic patients for whom treatment with just ziprasidone is appropriate.

Ziprasidone is also used off-label for depression, bipolar maintenance, mood disorders, anxiety, aggression, dementia, attention deficit hyperactivity disorder, obsessive compulsive disorder, autism, and post-traumatic stress disorder.

The oral form of ziprasidone is the hydrochloride salt, ziprasidone hydrochloride. The intramuscular form, on the other hand, is the mesylate salt, ziprasidone mesylate trihydrate, and is provided as a lyophilized powder.

• Ziprasidone (5-(2-(4-(1,2-benzisothiazol-3-yl-1-piperazinyl)-ethyl)-6-chloro-1,3-dihydro-2-(1H)-indol-2-one) is a potent antipsychotic agent and is useful for treating various disorders including schizophrenia, anxiety and migraine pain. Ziprasidone has been approved by the FDA for treatment of schizophrenia and goes by the brand name Geodon^™ in the United States. Ziprasidone has also been indicated as useful for treating Tourette’s Syndrome (United States Patent 6,127,373), glaucoma and ischemic retinopathy (EP 985414 A2), and psychiatric conditions including dementia of the Alzheimer’s type, bipolar disorders, mood disorders, panic disorders, agoraphobia, social phobia, panic disorder, post-traumatic stress disorder, acute stress disorder, substance-induced anxiety disorder, anxiety disorders not otherwise specified, dyskinesias and behavioral manifestations of mental retardation, conduct disorder, and autistic disorder (United States Patent 6,245,766).
• United States Patent 4,831,031 describes a genus of compounds encompassing ziprasidone and the synthesis of such compounds. Another method for synthesizing ziprasidone is described in United States Patent 5,206,366. A method for specifically synthesizingziprasidone hydrochloride monohydrate is described in United States Patent 5,312,925. A method for synthesizing ziprasidone mesylate dihydrate is described in United States Patent 6,245,765; and a method for synthesizing ziprasidone mesylate trihydrate is described in United States Patent 6,110,918. United States Patents 5,338,846; 5,359,068; and 6,111,105 also describe methods for synthesizing ziprasidoneand/or intermediates therefore.
• The structure of ziprasidone can be depicted as:

  (H. Howard, et al., “Ziprasidone Hydrochloride”, Drugs of the Future1994, 19(6): 560-563. As can be seen from the structure above, the compound ziprasidone comprises a chlorine atom.

• Methods of introducing halogens into organic compounds are summarized in many organic text books. For example, J. March,Advanced Organic Chemistry, 4^th Edition, pp. 587-591, and references cited therein, has a discussion of halogenation chemistry. More specifically, formation of chloro-aromatic compounds are frequently formed by a variety of methods also well known to those skilled in the art, and again summarized in J. March, Advanced Organic Chemistry, 4^th Edition, Chapter 11, “Aromatic Electrophilic Substitution”. The chemistry to add a halogen, or more specifically a chlorine, to an aromatic group is thus well known to those skilled in the art. It is also known that such chemistry usually results in some mixtures of molecules, one of which is commonly the unreacted starting material not containing the chlorine atom. Further, over-chlorination is a problem well known to those skilled in the art; it is common to form some dichloro-compound impurities when the mono-chloro is desired and some trichloro-compound impurities when the dichloro- is desired. Over-chlorination is typically controlled by limiting the amount of the chlorinating reagent used. Unfortunately, control of over-chlorinated analogs in the drug substance by limiting the amount of chlorinating reagent utilized in the introduction of the aromatic chlorine substituent would be expected to result in more of a des-chloro impurity (unreacted starting material not containing the chlorine atom).
• •  6-chlorooxindole (6-chloro-1,3-dihydro-2H-indol-2-one).
  • Although there are many known routes to 6-chlorooxindole, starting materials therefore are typically a substituted 4-chlorotoluene or 1,4-dichloro-nitrobenzene (see, G. J. Quallich and P. M. Morrissey,Synthesis, 1993, 51-53; and references cited therein; and F. R. Busch and R. J. Shine, “Development of an Efficient Process to 6-Chlorooxindole”, presented at the 208th ACS National Meeting in Washington D.C. in the Symposium on Technical Achievements in Organic Chemistry, 1994, (talk #126).). However, the concept of controlling chlorinated isomers, over-chlorination, or des-chloro impurities for the synthesis of 6-chlorooxindole is not described in the prior art. Other methods of synthesizing 6-chlorooxindole can be determined by a person of ordinary skill in the art, and such methods are included in the step of obtaining a batch of 6-chlorooxindole for the above-described method of this invention. Furthermore, a batch of 6-chlorooxindole can be obtained by purchase from manufacturers of organic chemicals, for example Plaistow, Ltd., Little Island, County Cork, Ireland or Finorga, Route de Givors, 38670 Chasse-Sur-Rhone, France.

Ziprasidone has two major fragments, benzisothiazol and substituted oxindole. In from 2 – mercapto acid methyl ester ( 1 ), the alkaline conditions with hydroxylamine-O-sulfonic acid reaction ring closure under alkaline conditions to obtain 5 . 5 3 can also be prepared from the disulfide, disulfides 3 by three methods (anthranilic acid by diazotization pass sulfur dioxide gas, o-fluorinated thiol acid and two xenon reaction, or dibromoethoxychlorophosphonazo acid and sulfur in copper iodide reaction), 3 and chlorinated sulfoxide and sulfone chlorination reaction of 4 , 4and ammonia reaction again 5 . 5 by chlorination with phosphorus oxychloride, the reaction of piperazine 7 . 7 may be made ​​of the compound 8 ( 8 can be from 2 – cyano bromobenzene After the i-PrMgCl, ZnBr 2 , S 2 Cl 2 prepared in one-pot reaction) was prepared in DMSO and directly in the hot reaction piperazine.
Oxindole fragment from 6 – chloro-indol-2 – one ( 10 ) starts, the FC acylation later reduction with triethylsilane 12 , 12 and 7 occurs in alkaline aqueous solution S N 2 reaction with hydrochloric acid salt to obtain ziprasidone hydrochloride.

United States Patent 5,206,366,

MORE INFO UPDATED

Ziprasidone is an antipsychotic agent with the following chemical name: 5-[2-[4-(1,2-benzisothiazol-3-yl)-1-piperazinyl]ethyl]-6-chloro-1,3-dihydro-2H-indol-2-one of formula (I)

Ziprasidone is disclosed in U.S. Pat. Nos. 4,831,031 and 5,312,925 (assigned to Pfizer). Ziprasidone inhibits synaptic reuptake of serotonin and norepinephrine. No appreciable affinity was exhibited for other receptor/binding sites tested, including the cholinergic muscarinic receptor. The mechanism of action of ziprasidone, as with other drugs having efficacy in schizophrenia, is unknown. However, it has been proposed that this drug’s efficacy in schizophrenia is mediated through a combination of dopamine type 2 (D 2) and serotonin type 2 (5HT 2) antagonism.Ziprasidone’s antagonism of histamine H receptors may explain the somnolence observed with this drug.

U.S. Pat. No. 5,312,925 (Pfizer Inc.) describes a process for the synthesis of monohydrate of 5-(2-(4-(1,2-benzisothiazol-3-yl)piperazinyl)ethyl)-6-chloro-1,3-dihydro-2H-indol-2-one hydrochloride and its characterization based on IR, XRD and moisture content. The ’925 patent also discloses that the hemihydrate may be obtained by the process described in Example 16 of U.S. Pat. No. 4,831,031 and its characterization by IR, XRD and moisture content. It also discloses the IR, XRD and moisture content of anhydrous Ziprasidone hydrochloride. According to the invention in the ’925 patent, Ziprasidone of water content of 3.97, 2.55 and 0.37% were used for the IR and XRD study of Ziprasidone hydrochloride monohydrate, hemihydrate and anhydrous. In this invention, the monohydrate ofZiprasidone hydrochloride was prepared by reacting anhydrous 5-(2-(4-(1,2-benzisothiazol-3-yl)piperazinyl)ethyl)-6-chloro-1,3-dihydro-2H-indol-2-one with aqueous hydrochloric acid. The temperature range of the reaction was maintained between 60 to 65° C. and aqueous hydrochloride used for salt formation was around 0.7 M. Depending on the reaction temperature and other conditions, the reaction times were set around 3 to 24 hours. The final product thus obtained was dried carefully in monitored conditions to make certain that water content was from about 3.8% to about 4.5% to obtain the stable monohydrate.

U.S. Pat. No. 6,150,366, discloses a manufacturing process of ziprasidonehydrochloride monohydrate, comprises: 1) dissolving, ziprasidone free base in a solvent comprising THF and water, in a volume ratio of about 22-35 unit volumes of THF to about 1.5-8 volumes of water; 2) heating the solution resulting from step (1); 3) adding HCl to the solution resulting from step (2); and 4) cooling the solution resulting from step (3) and crystals collected by filtration and drying.

U.S. Pat. No. 5,206,366 and U.S. Pat. No. 5,338,846 describe a process for preparing ziprasidone by reacting 1-(1,2-benzisothiazol-3-yl) piperazine with 5-(2-chloroethyl)-6-chloro-oxindole in water with a neutralizing agent such as sodium carbonate under reflux.

J. Med. Chem. 1996, 39, 143-148 discloses preparation of ziprasidone by reacting 1-(1,2-benzisothiazol-3-yl)piperazine with 5-(2-bromoethyl)-6-chloro-oxindole in isoamyl alcohol solvent in the presence of sodium carbonate.

Some salts of ziprasidone, and in particular, its hydrochloride salt is a potent commercial antipsychotic agent useful in the treatment of various disorders, including schizophrenia and anxiety diseases. Ziprasidone hydrochloride is currently marketed under the proprietary name of Geodon. Other salts ofziprasidone are also reported to be effective for the treatment of the same type of diseases.

Some of the processes described in the aforementioned patents necessitate the use of ion-exchange catalyst (i.e. sodium iodide) and/or phase transfer catalysts (for example tetra butyl ammonium bromide or tetra butyl phosphoriium bromide) in order for the coupling reaction producing ziprasidone to take place. For example, U.S. Pat. No. 4,831,031 indicates that arylpiperazinyl-ethyl (or butyl)-heterocydic compounds may be prepared by reacting piperazines of the formula II with compounds of the formula III as follows in [Scheme 1]:

Wherein Hal is fluoro, chloro, bromo or iodo; and Ar, n, X and Y are as defined therein with reference to formula I. According to the ’031 patent the coupling reaction is generally conducted in a polar solvent, such as a lower alcohol, dimethylformamide or methylisobutylketone, and in the presence of a weak base and that, preferably, the reaction is carried out in the presence of a catalytic amount of sodium iodide, hydrogen chloride and neutralizing agent such as sodium carbonate.

In some instances, the ziprasidone obtained was purified by column chromatography, thus making the process impractical for large-scale preparations. Another process uses potentially explosive gases such as hydrogen in the presence of catalysts, for example zinc, palladium on carbon, followed by acid treatment to carry out a reduction and cyclization of an intermediate, in order to obtain ziprasidone.

Despite various processes disclosed in the prior art for the preparation of ziprasidone and salts thereof, still there is a need for a good process for producing ziprasidone and pharmaceutically acceptable acid addition salts of ziprasidone thereof, in high purity. One of the major problems faced in the prior art is formation of sticky material and difficult stirrability of the reaction mass. This problem is especially acute in large scale manufacturing.

The SCRIP Awards 2013 celebrated achievements in the global biopharma industry last night at the Lancaster, London.

Hosted by Justin Webb, the evening was a fantastic mix of dining, entertainment and awards.

Among the winners were:

• Novartis’s Bexsero, Best New Drug
• Genmab, Biotech Company of the Year
• Regeneron Pharmaceuticals and Sanofi’s Phase IIa study dupilumab in asthma, Clinical Advance of the Year

You can view the full roll of honour by clicking on the button below.

It was a great night and we would like to thank all those who entered and attended this year’s awards.

Finally congratulations to our winners and a huge thanks to our sponsors for helping us make it such a fantastic success.

Don’t forget to check our website in the next couple of days for all the pictures from the night.

2013 Winners

Best Company in an Emerging Market - Sponsored by Clinigen Group

• Dr Reddy’s Laboratories – India

Best Technological Development in Clinical Trials

• Quintiles’s Infosario Safety

Best Partnership Alliance

• AstraZeneca with Bristol-Myers Squibb and Amylin in diabetes

Financing Deal of the Year

• Mesoblast’s equity financing of Aus$170m

Best Advance in an Emerging Market

• Novartis’s Jian Kang Kuai Che Healthcare Project in China

Clinical Advance of the Year - Sponsored by Quintiles

• Regeneron Pharmaceuticals and Sanofi’s Phase IIa study dupilumab in in asthma

Licensing Deal of the Year - Sponsored by Hume Brophy

• AstraZeneca and Horizon Discovery for the development and commercialization of the HD-001 kinase target program for multiple cancer types

Executive of the Year

• Roch Doliveux, chairman and chief executive officer of UCB

Biotech Company of the Year

• Genmab

Best Contract Research Organization

• Quintiles

Management Team of the Year

• Regeneron Pharmaceuticals’ CEO Leonard S Schleifer and CSO George D Yancopoulos

Best New Drug - Sponsored by INC Research

• Novartis’ Bexsero (meningococcal group B vaccine)

Pharma Company of the Year - Sponsored by ICON

• Astellas

Lifetime Achievement Award

• Prof Dr Désiré Collen

   

…….read about bexero at

http://newdrugapprovals.wordpress.com/2013/02/02/novartis-gets-european-approval-for-first-meningitis-b-vaccine/

DR ANTHONY MELVIN CRASTO Ph.D

amcrasto@gmail.com

Teva Announces Additional Regulatory Exclusivity for TREANDA® (Bendamustine HCI) for Injection

Orphan Designation combined with pediatric extension provides regulatory exclusivity through April 2016 for indolent B-cell non-Hodgkin lymphoma indication

JERUSALEM, November 27, 2013 –(BUSINESS WIRE)–Teva Pharmaceutical Industries Ltd. (NYSE: TEVA) today announced that the U.S. Food and Drug Administration (FDA) has granted orphan drug exclusivity for TREANDA through October 2015 for indolent B-cell non-Hodgkin lymphoma (iNHL) that has progressed during or within six months of treatment with rituximab or a rituximab-containing regimen.http://www.pharmalive.com/teva-announces-additional-regulatory-exclusivity-for-treanda

read my old post, contains synthesis

http://newdrugapprovals.wordpress.com/2013/09/19/fda-oks-tevas-injectable-treanda/

ZAFIRLIKAST 

cyclopentyl 3-{2-methoxy-4-[(o-tolylsulfonyl)carbamoyl]benzyl}-1-methyl-1H-indol-5-ylcarbamate

107753-78-6

Matassa, V.G. et al, J. Med. Chem., v. 33, 1781 (1990);

U. S. Patent No. 4,859,692;

U. S. Patent No. 5,993,859;

Zafirlukast is an oral leukotriene receptor antagonist (LTRA) for the maintenance treatment of asthma, often used in conjunction with an inhaled steroid and/or long-acting bronchodilator. It is available as a tablet and is usually dosed twice daily. Another leukotriene receptor antagonist is montelukast (Singulair), taken once daily. Zileuton (Zyflo), also used in the treatment of asthma via its inhibition of 5-lipoxygenase, is taken four times per day.

Zafirlukast blocks the action of the cysteinyl leukotrienes on the CysLT1 receptors, thus reducing constriction of the airways, build-up of mucus in the lungs andinflammation of the breathing passages.

Zafirlukast is marketed by Astra Zeneca with the brand names Accolate, Accoleit, and Vanticon. It was the first LTRA to be marketed in the USA and is now approved in over 60 countries, including the UK, Japan, Taiwan, Italy, Spain, Canada, Brazil, China and Turkey

Healthy young men who received a single oral 40 mg dose attained peak plasma zafirlukast concentrations that averaged 607 μg/L at 3.4 hours. The elimination half-life ranged from 12 to 20 hours. In another study involving a 20 mg single oral dose in healthy men, the elimination half-life averaged 5.6 hours.^[1][2]

A letter was submitted to the FDA by Zeneca Pharmaceuticals on July 22, 1997, notifying them of a change in product labeling that includes the following potential reaction in patients undergoing a dosage reduction of oral steroids who are currently taking zafirlukast:

PRECAUTIONS-Eosinophilic Conditions: The reduction of the oral steroid dose, in some patients on ACCOLATE therapy, has been followed in rare cases by the occurrence of eosinophilia, vasculitic rash, worsening pulmonary symptoms, cardiac complications, and/or neuropathy sometimes presenting as Churg–Strauss syndrome, a systemic eosinophilic vasculitis. Although a causal relationship with ACCOLATE has not been established, caution is required when oral steroid reduction is being considered.¹

Zafirlukast is a synthetic, selective peptide leukotriene receptor antagonist (LTRA), with the chemical name 4(5-cyclopentyloxy-carbonylamino-1-methyl-indol-3ylmethyl)-3-methoxy-N-o-tolylsulfonylbenzamide. The molecular weight of zafirlukast is 575.7 and the structural formula is:

The empirical formula is: C₃₁H₃₃N₃O₆S

Zafirlukast, a fine white to pale yellow amorphous powder, is practically insoluble in water. It is slightly soluble in methanol and freely soluble in tetrahydrofuran, dimethylsulfoxide, and acetone.

• Zafirlukast (U.S. National Library of Medicine)
• Zafirlukast (patient information)

Zafirlukast, cyclopentyl 3 – [2-methoxy-4- [(o-tolylsulfonyl)carbamoyl]- benzyl]-l-methyIindole-5-carbamate, having the formula:

is a first anti-asthmatic leukotriene antagonist (Matassa, V.G. et al, J. Med. Chem., v. 33, 1781 ^‘(1990); U. S. Patent No. 4,859,692 and The Merck Index, 12th Edition, 10241). Methods for the preparation of Zafirlukast are described in J. Med. Chem., v. 33, 1781 (1990), U. S. Patent 4,859,692 and U.S. Patent 5,993,859 starting from methyl 3-methoxy-4-(l-methyl-5-nitroindol-3-ylmethyl)benzoate [la]

Alkyl (l-alkylindol-3-ylmethyl)benzoates of formula [lb] are useful as chemical intermediates in the pharmaceutical industry.

These compounds may be obtained by a process described in J. Med. Chem., v. 33, 1781 (1990) and U. S. Patent 4,859,692. This process comprises the steps of:

(a) reacting an alkyl (halomethyl)benzoate of formula [2] with an equivalent amount of an indole of formula [3]

in the presence of an equivalent quantity of silver(I) oxide,

(b) isolating the alkyl (indol-3-ylmethyl)benzoates of formula [4] from the reaction mixture obtained in step (a) above,

(c) reacting the compound [4] with an alkylating agent of formula [6],

The above process has serious disadvantages in the isolation of the product [4] in step (b) which is due to the fact that alkylation of indole, that is unsubstituted at positions 1-, 2- and 3-, at the 3-position, is accompanied by the undesired process of poly alkylation, to form polysubstituted indoles of formula [7] and/or formula [8] :

while at the same time some quantity of the starting unreacted indole remains in the reaction mixture. Most common methods for the separation of alkyl (indol-3-ylmethyl)benzoate of formula [4] from by-products of polyalkylation and starting unreacted indole, which are all covalent compounds with similar physical properties, include column chromatography that is an unpractical method for industrial scale applications.

Formula (I) compound for the synthesis of an important intermediate of zafirlukast.Reported in the patent EP199543 synthesized compound (I) of the conventional method, the following formula:

(A) (I)

 In this method, Intermediate A and 5 – nitro-indole silver oxide in the presence of a catalyst, for docking composite formula (I) compound. Reported only 45% of the reaction yield, the reaction is difficult to complete the reaction and post-treatment using chromatographic methods, resulting in product purification more difficult. And the use of more expensive silver oxide catalysts, high cost.

 W00246153 reported a catalyst for the above reaction to zinc bromide, Compound (I), after treatment of the compound (I) with sodium hydroxide hydrolysis of the intermediate (B), separating the product and raw materials purification products.

 

The method reported in the literature a yield of 60%, but the actual operation is repeated only about 30% yield, and the operation is complicated, cumbersome and costly.

zaafirlukast is a selective and competitive receptor antagonist of leukotriene D4 and E4 (LTD4 and LTE4), components of slow-reacting substance of anaphylaxis (SRSA). Cysteinyl leukotriene production and receptor occupation have been correlated with the pathophysiology of asthma, including airway edema, smooth muscle constriction, and altered cellular activity associated with the inflammatory process, which contribute to the signs and symptoms of asthma.

The cysteinyl leukotrienes (LTC₄ LTD₄, LTE4) are the products of arachidonic acid metabolism and are various cells, including mast cells and eosinophills, these eicosinoids bind to cysteinyl leukotriene (CysLT) receptors. The CysLT type-1 (CysLT₁) receptor is found in human airway and other pro-inflammatory cells. CysLTs have been correlated with the pathophysiology of asthma.

Zafirlukast is a synthetic, selective peptide leukotriene receptor antagonist (LTRA), useful for the treatment of asthma and is commercially available in products sold under the brand name ACCOLATE™ as 10 and 20 mg tablets for oral administration. ACCOLATE™ is indicated for the prophylaxis and treatment of asthma in adults and children 5 years of age and older.

ACCOLATE™ film coated tablets contain amorphous zafirlukast as the active ingredient and the excipients croscarmellose sodium, lactose, magnesium stearate, microcrystalline cellulose, povidone, hypromellose, and titanium dioxide.

The greatest prevalence of asthma is in preschool children; however, the clinical utility of asthma therapy for this age group is limited by a narrow therapeutic index, long-term tolerability, and frequency and/or difficulty of administration. Asthma treatment requires an immediate perceivable effect. Inhalation therapy is a very common therapy prescribed for young children; inhalation therapy has the disadvantage of high dose variability.

Process for the preparation of zafirlukast
US 20040186300 A1

Argatroban
Molecular Formula: C23H36N6O5S
Formula Weight: 508.63
CAS No.: 74863-84-6 

(2R,4R)-1-[(2S)-5-(diaminomethylideneamino)-2-
[[(3R)-3-methyl-1,2,3,4-tetrahydroquinolin-8-yl]
sulfonylamino]pentanoyl]-4-methyl-piperidine-2-
carboxylic acid

PATENT

US 7,589,106, 7,687,516, EP 0008746; US 4258192, US 4201863

Argatroban is an anticoagulant that is a small molecule direct thrombin inhibitor.^[1] In 2000, argatroban was licensed by the Food and Drug Administration (FDA) for prophylaxis or treatment of thrombosis in patients with heparin-induced thrombocytopenia (HIT). In 2002, it was approved for use during percutaneous coronary interventions in patients who have HIT or are at risk for developing it. In 2012, it was approved by the MHRA in the UK for anticoagulation in patients with Heparin-Induced Thrombocytopenia Type II (HIT) who require parenteral antithrombotic therapy.^[2]

Argatroban is given intravenously and drug plasma concentrations reach steady state in 1-3 hours.^[3] Argatroban is metabolized in the liver and has a half-life of about 50 minutes. It is monitored by PTT. Because of its hepatic metabolism, it may be used in patients with renal dysfunction. (This is in contrast to lepirudin, a direct thrombin inhibitor that is primarily renally cleared).

Argatroban is used as an anticoagulant in individuals with thrombosis and heparin induced thrombocytopenia. Often these individuals require long term anticoagulation. If warfarin is chosen as the long term anticoagulant, this poses particular challenges due to the falsely elevated prothrombin time and INR caused by argatroban. The combination of argatroban and warfarin may raise the INR to greater than 5.0 without a significant increased risk of bleeding complications.^[4] One solution to this problem is to measure the chromogenic factor X level. A level < 40-45% typically indicates that the INR will be therapeutic (2-3) when the argatroban is discontinued.

1. Di Nisio M, Middeldorp S, Buller HR. Direct thrombin inhibitors. N Engl J Med2005;353:1028-40. PMID 16148288
2.  http://www.pharmatimes.com/Article/12-07-03/UK_launch_for_Mitsubishi_s_blood_thinner_Exembol.aspx
3.  Dhillon S. Argatroban: A Review of its Use in the Management of Heparin-Induced Thrombocytopenia. Am J Cardiovasc Drugs 2009; 9 (4): 261-82. Link text
4.  Hursting MJ, Lewis BE, Macfarlane DE. (2005). “Transitioning from argatroban to warfarin therapy in patients with heparin-induced thrombocytopenia.”. Clin Appl Thromb Hemost 11 (3): 279–87. doi:10.1177/107602960501100306. PMID 16015413.
5. Bioorg Med Chem Lett2001,11,(15):1989
6. Kikumoto, R., Tamao, Y., Onkubo, K., Tezuka, T., Tonomura, S., Hihikata, A. and Okamoto, S. (Mitsubishi Chem. Inds. Co., Ltd.); EP 8746, US 4258192.
7.  Kikumoto, R., Tamao, Y., Onkubo, K., Tezuka, T., Tonomura, S., Hihikata, A. and Okamoto, S. (Mitsubishi Chem. Inds. Co., Ltd.); US 4201863.

• GlaxoSmithKline’s website on argatroban

……………………………………………………….

Argatroban monohydrate

Argatroban is a synthetic direct thrombin inhibitor and the chemical name is 1-[5-[(aminoiminomethyl) amino]-1-oxo2[[(1,2,3,4-tetrahydro-3-methyl-8-quinolinyl)sulfonyl]amino]pentyl]-4-methyl-2- piperidinecarboxylic acid, monohydrate. Argatroban has 4 asymmetric carbons. One of the asymmetric carbons has an R configuration (stereoisomer Type I) and an S configuration (stereoisomer Type II). Argatroban consists of a mixture of R and S stereoisomers at a ratio of approximately 65:35.

The molecular formula of argatroban is C₂₃H₃₆N₆O₅S•H₂O. Its molecular weight is 526.66 g/mol. cas 141396-28-3

Argipidine, Argatroban monohydrate, GN1600, DK-7419, MDI-805 Acova, Slonnon, Novastan

Mitsubishi Chemical (Originator), Encysive Pharmaceuticals (Licensee), Mitsubishi Pharma (Distributor), Daiichi Pharmaceutical (Codevelopment), GlaxoSmithKline (Codevelopment), Mitsubishi Pharma (Codevelopment), Sanofi-SynthLabo (Codevelopment)

Antithrombocytopenic, CARDIOVASCULAR DRUGS, Cerebrovascular Diseases, Treatment of, HEMATOLOGIC DRUGS, Hematopoiesis Disorders Therapy, Ischemic Stroke, Treatment of, NEUROLOGIC DRUGS, Peripheral Vascular Disease, Treatment of, Stroke, Treatment of, Treatment of Peripheral Obstructive Vascular Disease, Thrombin Inhibitors

Synthesis of argatroban on the method reported in the literature there are two synthetic routes, patent EP8746, US4258192, US4201863, JP8115267 relates to a route is: with 4 – methyl-piperidine as a starting material was prepared first intermediate body (2R, 4R) -4 – methyl-2 – ethyl-piperidine, and the first and a t-BOC protected amino nitro-L-arginine condensation, and then the 3 – methyl – 8 – quinoline sulfonyl chloride condensation after hydrolysis, hydrogenation, hydration be argatroban. This entry route synthesis process complicated procedure to be carried out under the protection of nitrogen, the raw material is highly toxic gas phosgene, the operation more difficult.

US4117127, JP02-212473, EP823430, EP8746, JC S Perk Transl 1981 (5), JP02-212473 relates to an alternative route is: nitro L-arginine prior to the 3 – methyl-8 – subsequent condensation quinoline sulfonyl chloride Intermediate (2R, 4R) -4 – methyl-2 – piperidinecarboxylate condensation, and then after hydrolysis, hydrogenation, hydration be argatroban. This synthetic route despite the relatively simple process method, to obtain raw materials, but this method using reagents such as phosphorus oxychloride, phosphorus trichloride has a pungent odor, easy to absorb moisture in humid air, intense smoke, environmental pollution, greater stimulation of the body’s respiratory tract, can cause eye and skin irritation and burning, and the use of this method, complex operation, low yield, high cost.

Patent CN100586946C Argatroban discloses a method for separating optically active isomeric compounds, the feedstock argatroban mixed solvent of alcohol and water was heated to reflux 5-10 hours, cooled and allowed to stand, and filtered to give White crystalline product, dried, repeated 2-6 times. [0008] Patent CN101033223A discloses a Argatroban is the main by-product (2R, 4R)-l_ [N2-(3_ methyl-8 - quinolinesulfonyl)-L-arginyl] -4 – methyl-2 – carboxylic acid, argatroban, and the byproducts are difficult to isolate, argatroban two diastereomeric isomer 21 (S) and 21 (R) separation of work attracted a lot of research persons. Because both physical and chemical properties are very similar, so separation is very difficult. 1993 Rawson, Thomas E.; VanGorp, Kimmie A.; Yang, Janet so first by high pressure liquid chromatography and column chromatography separation to obtain a single 21 (S) and 21 (R) argatroban [ Journal of Pharmaceutical Sciences vol. 82, No. 6,672]; Thibaudeau Karen et al. reported Protein A chromatographic separation [US6440417]. However, due to the separation of these methods a small amount of low efficiency, so there is no practical value industrialization. 2006 China Tianjin Weijie Technology Co., Ltd. Song Honghai et al. Reported using recrystallization Separation 21 (S) and 21 (R) argatroban way [0 With 951,936 it], so that the mass 21 (5) Aga music classes as possible, but the law of low yield, complicated operation, high cost, and a large amount of a small amount of 21 (S) of 21 (R)-product argatroban, from the viewpoint of industrial production, is still a ideal method. [0009] These methods can be effectively prepared argatroban, but the purity of the desired product is not high, poor color, content is low, affecting the quality of the results of its preparation.

U.S. Pat. No. 4,201,863 (6 May 1980) and EP 8746 (filed on 22 Aug. 1979 with priority based on the application for the cited US patent) describe a class of N2-arylsulphonyl-L-argininamide drugs, with anti-thrombotic activity, and the processes for obtaining them. Of these, the compound 4-methyl-1-[N2-(3-methyl-1,2,3,4-tetrahydro-8-quinolinesulphonyl)-L-arginyl]-2-piperidine carboxylic acid (argatroban, isomers mixture) is described. The described process comprises the synthesis of an intermediate NG-substituted-N2-quinolinesulphonyl-L-argininamide from which the desired compound is obtained by catalyzed hydrogenolysis or acidolysis and catalyzed hydrogenation. The general conditions provided for the hydrogenolysis and hydrogenation reaction are: i) inert solvents (methanol, ethanol, tetrahydrofuran or dioxane); ii) presence of a catalyst (Raney nickel, palladium, platinum, ruthenium, rhodium); iii) hydrogen atmosphere at a pressure between 1 and 100 kg/cm2 and preferably between 5 and 50 kg/cm2; iv) temperature between 0° C. and 200° C. and preferably between 50° C. and 150° C.; v) reaction temperature from 2 hours to 120 hours. The crude product obtained is then purified by trituration or by re-crystallization from diethyl ether-tetrahydrofuran, diethyl ether-methanol or from water-methanol or by chromatography. No example is given of this purification step. In particular, both U.S. Pat. No. 4,210,863 and EP 8746 in example 1(E) describe the preparation of argatroban, isomers mixture. This compound is obtained in amorphous form by hydrogenation of [NG-nitro-N2-(3-methyl-8-quinolinesulphonyl)-L-arginyl]-4-methyl-2-piperidine carboxylic acid in ethanol in the presence of Pd/C with hydrogen pressure of 10 kg/cm2 at 100° C. for 8 hours. The catalyst is removed by filtration of the ethanol solution which is then evaporated without further purification and/or re-crystallization steps. In the US patent at issue as indeed in patent application EP 8746, no mention is made of polymorphic forms of the compounds and, for the obtained compound, the following characteristics are reported: Amorphous solid, I.R. (KBr) (cm−1) 3400; 1620; 1460; 1380; Molecular composition (%): theoretical C 54.31; H 7.13; N 16.52; found (%) C 54.01; H 6.98; N 16.61.

U.S. Pat. No. 4,258,192 (24 Mar. 1981) (continuation-in-part of the aforesaid patent application U.S. Pat. No. 4,201,863) and the same patent application EP 8746 describe the stereoisomers and the preparation thereof, including argatroban used as an active principle in medicaments, i.e. the stereoisomer (2R,4R)-4methyl-[4N2-(3-methyl-1,2,3,4-tetrahydro-8-quinolinesulphonyl)-L-arginyl]-2-piperidine carboxylic acid, with the following characteristics: melting point (m.p.). 188-191° C.; I.R. (KBr) (cm−1) 3400, 1620, 1460, 1380; Molecular composition (%): theoretical C 54.31; H 7.13; N 16.52; found (%) C 54.05; H 6.94; N 16.65. The compound is prepared according to the description given in examples 1(E) in U.S. Pat. No. 4,258,192 and 2(E) and 3 in EP 8746 respectively by hydrogenation of (2R,4R) 1-[NG-nitro-N2-(3-methyl-1,2,3,4-tetrahydro-8-quinolinesulphonyl)-L-arginyl]-2-piperidine carboxylic acid in ethanol in presence of acetic acid catalyzed by Pd/C. After filtering the mass to remove the catalyst, the solvent is evaporated and the residue suspended in chloroform, the solution treated with a saturated sodium bicarbonate solution or 1N sodium hydroxide solution and after washing, the solvent is evaporated. The compound is then re-crystallized from ethanol. Again in this case, no reference is made to the obtainment of monohydrate polymorphic forms.

Said polymorphic forms are described instead in the publication Biochem. Biophys. Res. Comm. 1981, 101, 440-446 in the context of stereoisomer preparation. The monohydrate polymorph of the (2R,4R) stereoisomer is prepared by re-crystallization from ethanol/water and the reported characteristics are: m.p. 176-180° C.; [α]D 27 +76.1° (c 1, 0.2N HCl).

U.S. Pat. No. 5,925,760 (20 Jul. 1999) and EP 0823430 (filed 4 Aug. 1997) subsequently describe a new method for preparing argatroban by means of a new intermediate N2-(3-methyl-8-quinolinesulphonyl)-NG-nitro-L-arginine. In particular the patent makes reference to the preparation of a crystalline monohydrate form of argatroban, referring back to examples (D) and (E) of Japanese patent publication No. (Hei)-2-31055/1990 and generically to an I.R. spectrum identical to that of the commercially available argatroban compound. The relevant example in the cited patent publication is example (E), while example (D) concerns the preparation of (2R,4R)-1-[NG-nitro-N2-(3-methyl-8-quinolinesulphonyl)-L-arginyl]-4-methyl-2-piperidine carboxylic acid. This compound represents the starting compound for argatroban preparation by catalytic reduction in the presence of Pd/C. The crude argatroban obtained is then purified by extraction with chloroform, treatment with a saturated sodium bicarbonate solution and, after solvent evaporation, re-crystallization from ethanol or from 15% alcohol in water. It should be noted however that the Japanese patent makes no mention of the monohydrate form of argatroban being obtained and that for the compound the following characteristics are reported: m.p. 188-191° C.; molecular composition (theoretical/found) (%): C 54.31/54.01; H 7.13/6.98; N 16.52/16.61; I.R. (KBr) (cm−1) 3400; 1620; 1460; 1380. These analytical data, with the exception of the unreported melting point, are the same as those indicated in the cited patent documents describing a mixture of (2R,4R)-4methyl-[4N2-(3S-methyl-1,2,3,4-tetrahydro-8-quinolinesulphonyl)-L-arginyl]-2-piperidine carboxylic acid and (2R,4R)-4methyl-1-[N2-(3R-methyl-1,2,3,4-tetrahydro-8-quinolinesulphonyl)-L-arginyl]-2-piperidine carboxylic acid isomers of argatroban, but do not correspond to the melting point given in the publication, being the only document that identifies the monohydrate form of argatroban.

More recently, patent application CN 1,951,937 (filing date 10 Nov. 2006) described a method for preparing hydrated argatroban by treating argatroban with large quantities of water (more than 60 and up to 80 volumes of distilled water per gram of argatroban) at a temperature of 80-100° C. for a time of 0.5-1 hour and crystallization by cooling. The water content reported is comprised between 3.3 and 3.8% and the ratio of dextroisomer R to levoisomer S is R:S=63-67: 37-33.

Argatroban is a compound of wide therapeutic use, for which reason the need still exists to provide a compound of pharmaceutically acceptable quality obtained by easily industrialized and economically convenient methods. With regard to the monohydrate, this form is preferable for the applicative purpose since the anhydrous form is unstable and tends to become hydrated and/or wet. Moreover it crystallizes only with difficulty at the correct ratio between the diastereoisomers.

…..

the protection of 4-methylpiperidine (I) with (Boc)2O gives the carbamate (II), which is condensed with benzyl chloroformate by means of sec-butyl lithium and TMEDA in ethyl ether to yield (?-trans-1-(tert-butoxycarbonyl)-4-methylpiperidine-2-carboxylic acid benzyl ester (III). Deprotection of the NH group of (III) with HCl in ethyl acetate affords (?-trans-4-methylpiperidine-2-carboxylic acid benzyl ester (IV), which is condensed with the protected arginine derivative (V) by means of isobutyl chloroformate and TEA to provide the corresponding amide as a diastereomeric mixture. Resolution of this mixture by flash chromatography furnishes the desired diastereomer (VI), which is treated with HCl in ethyl acetate in order to remove the Boc-protecting group to yield compound (VII). Condensation of compound (VII) with 3-methylquinoline-8-sulfonyl chloride (VIII) by means of TEA in dichloromethane affords the expected sulfonamide (IX). Finally, this compound is submitted to hydrogenation with H2 over Pd/C in AcOH/ethanol in order to produce debenzylation, cleavage of the NO2 group and hydrogenation of the pyridine ring to yield argatroban.

………….

Argatroban, i.e., (2R,4R)-1-((2S)-5-((Aminoiminomethyl)amino)-1-oxo-2-((1,2,3,4-tetrahydro-3-methyl-8-quinolinyl)sulfonyl)amino) pentyl)-4-methyl-2-piperidine carboxylic acid, has two diastereoisomers: 21(R) and 21(S). Usually the ratio of 21(R) to 21(S) is 64-65: 36-35 (U.S. Pat. No. 6,440,417, Cossy. J., et al, Bioorganic & Medicine Chemistry Letters, 11 (2001), 1989-1992, Journal of pharmaceutical Sciences, Vol. 82, No. 6, 672 (1993)).

The structure formula of Argatroban is reported below:

• • 21(S) Argatroban, X=CH₃, Y═H;
  • 21(R) Argatroban, X=H, Y=CH₃;
  • Argatroban, 21(S): 21 (R)=35:65.

The chemical names of the two diastereoisomers mentioned above are:

• 21(S) Argatroban: (2R,4R)-1-((2S)-5-((Aminoiminomethyl)amino)-1-oxo-2-((((3S)-1,2,3,4-tetrahydro-3-methyl-8-quinolinyl)sulfonyl)amino)pentyl)-4-methyl-2-piperidine carboxylic acid (121785-72-6); and
• 21(R) Argatroban: (2R,4R)-1-((2S)-5-((Aminoiminomethyl)amino)-1-oxo-2-((((3R)-1,2,3,4-tetrahydro-3-methyl-8-quinolinyl)sulfonyl)amino)pentyl)-4-methyl-2-piperidine carboxylic acid (121785-71-5).

In 1978, S. Akamoto et al from Japanese Mitsubishi Chemical Corporation first disclosed the anti-thrombin activity of Argatroban monohydrate (U.S. Pat. No. 4,101,653). In the next 20 years, numerous researchers had in-depth studies on Argatroban about its biological activity and medicine values. In 1981, S. Akamoto compared Argatroban with heparin in vivo (Okamoto, S. et al., Biochem. Biophys. Res. Commun. 101, 440 (1981)); T. Kumoto disclosed its three-dimensional selective activity (Kumada, T. et al., Thromb. Res. 24, 285 (1981)). In 1984, R. Kumato made a clinical evaluation of hemodialysis of Argatroban (Kikumoto, R. et al., Biochemistry 23, 85 (1984)), and in 1986, he further disclosed that Argatroban can inhibit the thrombin activity of mammals, and can be used as active ingredient to treat and prevent thrombosis and as an inhibitor of platelet aggregation. Argatroban monohydrate can be used as a selective anti-thrombosis agent for treatment of chronic arterial blockage and cerebral thrombosis, etc (JP 61-48829). In 1992 and 1993, Taparelli and Jakubowski separately disclosed the reversibility of Argatroban in anti-thrombin (Taparelli, C., Trends Pharmacol. Sci., 1993, 14, 366, Jakubowski, J. A. et al, Rep. Med. Chem., 1992, 27, 99). In 1990s, many researchers such as L. R. Buch reported other related research (Buch, L. R., Cadiosvasc. Drug Rev., 1991, 9, 247, Strupcnewski, J. D. et al., Academic: San Diego, 1991; Vol. 26, p 299, Brundish, D. et al., J. Med. Chem. 1999; 42, 4584, Shebuski, R. J., Academic: San Diego, 1999; Vol. 26, p 98). In 1992, Argatroban monohydrate was first approved as an anti-thrombin medicine in Japan (Hijikata-Okunomiya, A., et al, Thromb. Hemostasis, 1992, 18, 135).

IRBESARTAN, SR 47436, BMS-186295

Avapro® (Bristol-Myers Squibb) and Karvea®
(Sanofi-Winthrop)

2-butyl-3-({4-[2-(2H-1,2,3,4-tetrazol-5-yl)phenyl]phenyl}methyl)-1,3-diazaspiro[4.4]non-1-en-4-one

138402-11-6  CAS NO

U.S. Patents 5,270,317 and 5,352,788, 6,162,922

The compound prepared according to US 5270317 is polymorph A

• Irbesartan is known by following chemical names:

  1. (a) 2-Butyl-3-[[2'-(1H-tetrazol-5-yl)[1,1'-biphenyl]-4-yl]methyl]-1,3-diazaspiro[4,4]non-1-en-4-one
  2. (b) 2-Butyl-3-[p-(o-1H-tetrazol-5-ylphenyl)benzyl]-1,3-diazaspiro[4,4]non-1-en-4-one
  3. (c) 2-n-butyl-4-spirocyclopentane-1-[(2'-(tetrazol-5-yl)biphenyl-4-yl) methyl]-2-imidazolin-5-one.
• The structural formula of Irbesartan is represented below.

  Irbesartan

• The synthesis of irbesartan is first disclosed in US5270317 (equivalentEP0454511 ) and subsequently, several other patents disclose the synthesis of irbesartan by different methods. Basically the synthesis of this molecule involves two common intermediates namely spiroimidazole and substituted 4′-bromomethylbiphenyl.
• US 5270317 describes preparation of irbesartan wherein 1-[(2'-cyanobiphenyl-4-yl)methyl]-2-n-butyl-4-spirocyclopentane-2-imidazolin -5-one which is reacted with tributyltin azide in xylene at reflux temperature for 66 hours to give a product which is isolated from the reaction mass as trityl irbesartan and then deprotected in methanol/THF mixture using 4N hydrochloric acid to get irbesartan.
• US5629331 describes a process for the preparation of irbesartan from 1-[(2'-cyanobiphenyl)4-yl)methyl]-2-n-butyl-4-spirocyclopentane-2-imidazolin-5-one using sodium azide, TEA.HCl in N-methylpyrrolidone. The product is isolated from the alkaline reaction mass after acidification to pH 4.7 to 5.8 and the crude product is recrystallised from IPA/water to get Form A and ethanol/water to get Form B.

Irbesartan (INN) /ɜrbəˈsɑrtən/ is an angiotensin II receptor antagonist used mainly for the treatment of hypertension. Irbesartan was developed by Sanofi Research (now part ofsanofi-aventis). It is jointly marketed by sanofi-aventis and Bristol-Myers Squibb under thetrade names Aprovel, Karvea, and Avapro.

It is marketed in Brazil by Sanofi-Aventis under the trade name Aprovel .

As with all angiotensin II receptor antagonists, irbesartan is indicated for the treatment ofhypertension. Irbesartan may also delay progression of diabetic nephropathy and is also indicated for the reduction of renal disease progression in patients with type 2 diabetes,^[1]hypertension and microalbuminuria (>30 mg/24 hours) or proteinuria (>900 mg/24 hours).^[2]

Irbesartan is also available in a combination formulation with a low dose thiazide diuretic, invariably hydrochlorothiazide, to achieve an additive antihypertensive effect. Irbesartan/hydrochlorothiazide combination preparations are marketed under similar trade names to irbesartan preparations, including Irda, CoIrda, CoAprovel, Karvezide,Avalide and Avapro HCT.

A large randomized trial following 4100+ men and women with heart failure and normal ejection fraction (>=45%) over 4+ years found no improvement in study outcomes or survival with irbesartan as compared to placebo.^[3]

BMS annual sales approx $1.3bn. Sanofi-aventis annual sales approx $2.1bn. In the United States, a generic version is available. Patent expired March 2012.

1. Lewis EJ, Hunsicker LG, Clarke WR, Berl T, Pohl MA, Lewis JB, Ritz E, Atkins RC, Rohde R, Raz I; Collaborative Study Group. (2001). “Renoprotective effect of the angiotensin-receptor antagonist irbesartan in patients with nephropathy due to type 2 diabetes”. N Engl J Med 345 (12): 851–60. doi:10.1056/NEJMoa011303.PMID 11565517.
2.  Rossi S, editor. Australian Medicines Handbook 2006. Adelaide: Australian Medicines Handbook; 2006. ISBN 0-9757919-2-3
3.  Massie BM, Carson PE, McMurray JJ, Komajda M, McKelvie R, Zile MR, Anderson S, Donovan M, Iverson E, Staiger C, Ptaszynska A (December 2008). “Irbesartan in patients with heart failure and preserved ejection fraction”. N. Engl. J. Med. 359 (23): 2456–67.doi:10.1056/NEJMoa0805450. PMID 19001508.

4……….C. A. Bernhart, P. M. Perreaut, B. P. Ferrari, Y. A. Muneaux,
J.-L. A. Assens, J. Clement, F. Haudricourt, C. F. Muneaux,
J. E. Taillades, M.-A. Vignal, J. Gougat, P. R. Guiraudou, C.
A. Lacour, A. Roccon, C. F. Cazaubon, J.-C. Brelihre, G. Le
Fur, D. Nisato, J. Med. Chem. 1993, 36, 3371–3380.
5…. K. F. Croom, M. P. Curran, K. L. Goa, Drugs 2004 64,
999–1028.
6… C. Bernhard, J.-C. Breliere, J. Clement, D. Nisato, P. M. Perreaut, C. F. Muneaux, (Elf Sanofi) US 5 270 317; Chem. Abstr. 1993, 119, 95560.
7. S. Chava, M. Bandari, K. S. Mathuresh, (Matrix Laboratories) WO 2005/122699; Chem. Abstr. 2005, 144, 88292.
5. S. Zupan~i~, A. Pe~avar, R. Zupet, (Krka) WO 2006/073376;
Chem. Abstr. 2006, 145, 124576.
8. C. V. Kavitha, S. L. Gaonkar, J. N. Chandra, S. Narendra, C.
T. Sadashiva, K. S. Rangappa, Bioorg. Med. Chem. 2007, 15,
7391–7398.
9. S. Rádl, J. Stach, O. Klecán, (Zentiva) WO 2005/021535;
Chem. Abstr. 2005, 142, 298118.
10. B. Satyanarayana, Y. Anjaneyulu, P. Veerasomaiah, P. P.
Reddy, Heterocycl. Commun. 2007, 13, 223–228.
11. V. V. Korrapati, P. Rao, R. Dandala, V. K. Handa, I. V. S. Rao,
A. Rani, A. Naidu, Synth. Commun. 2007, 37, 2897–2905.
12. J. Havlí~ek, Z. Mandelová, R. Weisemann, I. Strˇelec, S.
Rádl, Collect. Czech. Chem. Commun. 2009, 77, 347.

Irbesartan of formula (I).

The chemical name of Irbesartan is 2-Butyl-3-[[2'-(lH-tetrazol-5-yl)[l,l'-biphenyl]-4- yl]methyl]-l,3-diazaspiro[4,4]non-l-en-4-one and formula is C₂SH₂SN₆O and molecular weight is 428.53. The current pharmaceutical product containing this drug is being sold by Sanofi Synthelabo using the tradename AVAPRO, in the form of tablets. Irbesartan is useful in the treatment of diabetic neuropathy, heart failure therapy and hypertension. Irbesartan is angiotension II type I (AΙIi)-receptor antagonist. Angiotension II is the principal pressor agent of the rennin-angiotension system and also stimulates aldosterone synthesis and secretion by adrenal cortex, cardiac contraction, renal resorption of sodium, activity of the sympathetic nervous system and smooth muscle cell growth. Irbesartan blocks the vasoconstrictor and aldosterone- secreting effects of angiotension II by selectively binding to the ATi angiotension II receptor. U.S. Pat. Nos. 5,270,317 and 5,559,233 describes a process for the preparation of N- substituted heterocyclic derivatives which involves reacting a heterocyclic compound of the formula

with a (biphenyl-4-yl)methyl derivative of the formula

wherein R₁, R₂, R₃, R₄, R₅, and t, z and Hal have the meanings given in said U.S. Pat. No.

5,270,317, in the presence of an inert solvent such as DMF, DMSO or THF, with a basic reagent, for example KOH, a metal alcoholate, a metal hydride, calcium carbonate or triethylamine. The products of the reaction were purified by chromatography.

U.S. Pat. Nos. 5,352,788, and 5,559,233, and WO 91/14679 also describe identical alkylation of the nitrogen atom of the heterocyclic compound with the halo-biphenyl compound using the same inert solvent and the same basic reagents.

• US5629331 describes a process for the preparation of irbesartan from 1-[(2'-cyanobiphenyl)4-yl)methyl]-2-n-butyl-4-spirocyclopentane-2-imidazolin-5-one using sodium azide, TEA.HCl in N-methylpyrrolidone. The product is isolated from the alkaline reaction mass after acidification to pH 4.7 to 5.8 and the crude product is recrystallised from IPA/water to get Form A and ethanol/water to get Form B.
• WO 2005/051943 A1 describes a process for the preparing irbesartan wherein 1-[(2'-cyanobiphenyl-4-yl)methyl]-2-n-butyl-4-spirocyclopentane-2-imidazolin-5-one is reacted with tributyltin chloride, sodium azide and TBAB in toluene at reflux temperature for 20 hours. Product is isolated from the reaction mass as trityl irbesartan and then deprotected in methanol and formic acid to get irbesartan.
• WO 2006/023889 describes a method for preparing irbesartan, wherein 1-(2′-cyanobiphenyl-4-yl)methyl)-2-n-butyl-4-spirocyclopentane-2-imidazolin-5-one is reacted with sodium azide and triethylamine hydrochloride in N-methyl-2-pyrrolidone to give irbesartan.
• WO 2005/113518 describes a process for preparing irbesartan wherein cyano irbesartan in xylene, is reacted with tributyltin chloride and sodium azide at reflux temperature till reaction is completed followed by aqueous work-up and recrystallization to give irbesartaN
• The process involving use of zinc salt for the transformation of nitrile to tetrazole is a safe and efficient process as reported in JOC (2001) 66, 7945-50. The use of zinc salt for transforming nitrile to tetrazole has also been published in WO9637481 and US5502191 

Also Canadian Patent No. 2050769 describes the alkylation of the nitrogen atom of the heterocycle of the formula

with a compound of the formula

wherein X, R₁, Z₁ and Z₆ have the meanings given therein, in the presence of N,N- dimethylformamide and a basic reagent, such as alkali metal hydrides for example sodium or potassium hydride.

All of the above identified patents describe alkylation in solvents, such as N₅N- dimethylformamide or DMSO, etc. in the presence of a basic reagent, for example, a metal hydride or a metal alcoholate etc. The strong bases, such as metal hydride or a metal alcoholate require anhydrous reaction conditions. Since N,N-dimethylformamide is used as a solvent, its removal requires high temperature concentration by distillation, which can result in degradation of the final product. The product intermediate is also purified by chromatography which is commercially not feasible and cumbersome on large scale. Another process given in Canadian Patent No. 2050769 provides synthetic scheme as herein given below.

This process comprises the steps of protecting carboxylic group present on cyclopentane ring which is deprotected in consecutive step by vigourous hydrogenation condition in autoclave which is operationally difficult at a large scale.

US Patent No. 2004242894 also discloses the process of preparation of lrbesartan from 4- bromomethyl biphenyl 2′-(lH-tetrazol (2-triphenylmethyl) 5-yl) and Ethyl ester of 1- Valeramido cyclopentanecarboxylic acid in toluene in presence of base and PTC, and then hydrolyzing the protecting group. However this requires chromatographic purification.

This patent also discloses the process of preparation of tetrazolyl protected lrbesartan using 2,6 lutidine and oxalylchloride in toluene. However in this process the yield is as low as 30%.

US Patent No. 2004192713 discloses the process of preparation of lrbesartan by condensing the two intermediates via Suzuki coupling reaction. The reaction scheme is as given herein below.

However, this process has several disadvantages such as use of the reagents like butyl lithium and triisobutyl borate at low temp such as -20 to -30°C under Argon atmosphere condition which is difficult to maintain at commercial scale.

WO2005113518 discloses the process of preparation of Irbesartan by condensing n- pentanoyl cycloleucine (V) with 2-(4-aminomethyl phenyl) benzonitrile (VI) using dicyclocarbodiimide (DCC) and 1 -hydroxy benzotriazole as catalyst to give an open chain intermediate of formula (VIII) which is then cyclized in the presence of an acid, preferably trifluoro acetic acid to give cyano derivative of formula (VII) and which in turn is converted to Irbesartan by treating it with tributyl tin chloride and sodium azide.

In this application further describes another process comprising the steps of reacting 2- butyl-l,3-diazasρiro[4,4]non-l-en-4-one monohydrochloride (A) with 4-bromobenzyl bromide (B) in presence of base and solvent to give 3-[4-bromobenzyl]-2-butyl-l,3- diazaspiro[4,4]non-l-en-4-one (C) which is condensed with 2-[2'-(triphenylmethyl-2'H- tetrazol-5'-yl)phenyl boronic acid in the presence of tetrakis triphenyl phosphine palladium and base to give lrbesartan (I). However these processes suffer with several disadvantages such as it uses trifluoroacetic acid for the cyclization step which is highly corrosive material. The process requires an additional step of activation by DCC. This step not only increases number of steps but also create problem in handling DCC at an industrial scale as it is highly prone to hazard which makes the process least preferred on a large scale production of lrbesartan. Further it uses phenyl boronic acid derivative and triphenyl phosphine complex which are harmful for the skin and eye tissue and also harmful for respiratory system. Tetrakis triphenyl phosphine palladium is also a costly material which increases overall cost for the production of lrbesartan. Moreover the yield is as low as 22%. All the above patents/applications are incorporated herein as reference. In summary, prior art relating to the process for the preparation of lrbesartan suffers with several drawbacks such as i) It requires chromatographic purification of intermediates at various stages. ii) It requires specific autoclave conditions for a deprotection of protecting group. iii) It requires maintaining low temperature conditions such as -30⁰C and requires special handling care and air and moisture tight condition with the reagents such as butyl lithium and triisobutyl borate. iv) It uses hazardous and highly corrosive reagents, v) It suffers low yield problem. vi) All the process is having more number of reaction steps.

• Irbesartan is described in Bernhart et al., U.S. Patent No. 5,270,317 
• Irbesartan, is a potent, long-acting angiotensin II receptor antagonist which is particularly useful in the treatment of cardiovascular ailments such as hypertension and heart failure. Its chemical name is2-n-butyl-4-spirocyclopentane-1-[(2'-(tetrazol-5-yl)biphenyl-4-yl)methyl]-2-imidazolin-5-one.

Irbesartan is an antihypertensive agent known from EP 454511. From EP 708103, which discloses their X-ray spectra, two polymorphs are known where form A can be produced form a solvent system containing less than 10% of water, while Form B from a system with more than 10% of water. The specific morphological variant of form A can be prepared having properties as disclosed in EP 1089994. Additional form has been disclosed in WO 04089938. Amorphous irbesartan is known from WO 03050110. It is said that Irbesartan produced as taught in EP 454511 is a fluffy material with relatively low bulk and tap densities and undesirable flow characteristics, which consequently has unadvantageous electrostatic properties, among them a high chargeability as measured by tribugeneration between -30 and -40 nanocoulomb/g (10^’9As/g). Alternativelyirbesartan could be prepared by complex process using sonifications and/or temperature oscillations according to EP 1089994 to exhibit a chargeability as measured by tribugeneration between -0 and -10 nanocoulomb/g.

According to EP 454511 a solid composition in form of tablets is prepared by mixing the active ingredient with a vehicle such as gelatine, starch, lactose, magnesium stearate, talc, gum Arabic or the like and can be optionally coated. The compositions containing from 20% to 70% by weight of irbesartan are known from EP 747050.

WO 04/007482 teaches the acidification to pH 2 – 3,5 of trityl irbesartan, which is sufficient to remove the protecting group, but not to convert into an acid addition salt; WO 04/065383 is likewise silent on hydrohalide acid addition salts. WO
06/011859 relates to the preparation of a hydrochloride salt of irbesartan in order to incorporate it into a pharmaceutical formulation. W099/38847 mentions optional conversion of irbesartan into hydrochloride, hydrobromide or hydrogen sulfate salts

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WO2006023889A2

Example 1Preparation of Compounds of formula IVa and IVb:

• A jacketed 1,000 mL 3-neck flask was charged with 4′-methylbiphenyl-2-carbonitrile (Compound 1, 100.0 g) and CH₂CI₂ (500 mL) under nitrogen. To a 500 mL Erlenmeyer flask with magnetic stirrer, sodium bromate (NaBrO₃; 31.2 g) was dissolved in water (170 mL). The NaBrO₃ solution was transferred to the 1,000 mL flask and the reaction mixture was cooled to about 5 °C or less. Aqueous HBr solution (48 %, 105.0 g) was added to the 1,000 mL flask and the resulting reaction mixture was recycled though a UV lamp reactor. The reaction mixture was kept at 0-20 °C and the recycling was continued until the reaction was deemed complete by HPLC. Optionally, additional sodium bromate and hydrogen bromide may be added. The relative amounts of Compound 2 and Compound 3 were about 80-90% and about 10-20% respectively. Aqueous sodium metabisulfite solution (2.0 g of in 10 mL water) was added to the reaction mixture. Allow the phases to settle and the methylene chloride phase was washed with water and used in the next step without further purification.

Example 2Preparation of Compound II:

• A 1L 3-neck flask was charged with Compound V (134.0 g), MTBAC (5.0 g) and CH₂Cl₂ (170 mL) and cool to -5 to 5 °C. An aqueous solution of KOH (182.6 g in 212 mL water) was added slowly to the 1L flask and the reaction temperature was kept at ≤ 5 °C. The methylene chloride solution of Compound IVa and Compound IVb from Example 1 was added to the reaction mixture slowly, while maintaining the temperature at 0-10 °C. Diethyl phosphite (39.66g) was added drop wise at 0-10 °C. Check the reaction mixture for completion of the reduction reaction, and additional diethyl phosphite may be added.
• The reaction mixture was allowed to warm to ambient (20-30 °C) and agitated until the reaction was deemed complete by HPLC. Water (150 mL) was added and the phases were separated. The organic layer was extracted with water (230 mL) and polish filtered.
• The methylene chloride (which contained the crude Compound II) was distilled off and exchanged with about 400 mL of methyl tert-butyl ether (MTBE) (optionally, the MTBE recycled from washing below can be used here). Upon cooling, crystallization occurred (optionally seeds were added) and after further cooling to below 25°C, crystals of Compound II were isolated, washed with MTBE and dried in vacuum at a temperature of less than 60°C. HPLC retention time: 18.126 min. Typically, the yield was about 85 to about 88%. Alternatively, IPA could be used as the crystallization and washing solvent
• Optionally, the solvent (i.e., MTBE or IPA) used to wash the crystals of Compound II above can be recycled and used to crystallize the crude Compound II in the next batch. Since the washed solvent contains Compound II as well as impurities, it was surprisingly found that the washed solvent can be recovered and used again in crystallizing the crude compound of formula II in the next batch without sacrificing its purity while increasing its yield.

Example 3Preparation of Compound I:

• A reactor was charged with Compound II (1 kg), triethylamine chlorhydrate (0.713 kg), sodium azide (0.337 kg) and N-methyl pyrrolidinone (2.07 kg), and the reaction mixture was heated to about 122°C under stirring. After completion of the reaction as determined by HPLC, the reaction mixture was cooled to about 45°C, and an aqueous solution of sodium hydroxide (35%, 5.99 kg) and water (3.0 kg) were added, the resulting mixture was stirred at a temperature between about 20 and about 40°C for about 0.5 hours. The aqueous phase was discarded and the organic phase was treated with toluene (1.73 kg) and water (5.0 kg), and stirred for about 0.5 hours at about 20 – about 30°C. The toluene phase was discarded and the aqueous phase was washed with ethyl acetate (1.8 kg) and treated with aqueous HCl until pH was adjusted to about 4.8 – about 5.2. Precipitation occurred and the resulting suspension was stirred for about 1 hour at about 20 – about 25°C. The precipitation was collected and washed with water three times (1.0 kg x 3). The crude wet product was recrystallized using a mixture of iso-propanol (0.393 kg) and water (4.5 kg). HPLC retention time: 11.725 min. The yield for Compound I was about 87%.

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SPECTRAL DATA

The ESI mass spectrum of irbesartan showed a protonated molecular ion peak at m/z 429.3 confirming the molecular weight 428. The fragmentation pattern of parent ion 429.3 showed the fragment ions at m/z 385.9, 235.1, 207, 195.4, 192.1, 180.2 and 84

The FT-IR spectrum exhibited a characteristic stretching absorption band at 1732 cm-1 for the carbonyl group of amide functionality. The presence of this band at higher frequency was due to the ring stretching due to five member ring system. Another band at 1614cm-1 was due to C=N stretching vibrations

1H and 13C- NMR were recorded using DMSO-d6 as a solvent. In 1H-NMR the signal due to tetrazole NH proton was not detected may probably due to the tautomerism.

SEE

http://orgspectroscopyint.blogspot.in/2013/12/irbesartan-spectral-data.html

DP 1 IS IMPURITY

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NMR

WO2007049293A1

¹H-NMR (DMSO d6): δppm 0.78 (t, 3H); 1.17-1.30 (sex, 2H); 1.40-1.50 (quent, 2H); 1.64-1.66 (m, 2H); 1.80-1.82 (m, 6H); 2.22-2.29 (t, 2H); 4.67 (s, 2H); 7.07 (s, 4H); 7.50- 7.68 (m, 4H) M⁺: 429.6

,…………………..

m.p:181-182oC,

IR (KBr, cm-1) 1732 (C=O), 1616 (C=N); 1H NMR (DMSO-d6): δ 7.95–7.32 (m, 8 H), 4.80 –4.60 (s, 2 H), 3.60– 3.00 (br s, 1 H), 2.40– 2.20 (t, 2 H , J = 6.04 Hz), 2.00– 1.60 (m, 8 H),1.60–1.45 (quint, 2 H), 1.40– 1.20 (sext, 2 H), 0.91–0.70 (t, 3H, J = 7.41 Hz);

13C-NMR (DMSOd6): δ 186.5, 162.0,155.9, 141.9, 139.2, 137.2. 131.9, 131.4, 130.1, 128.7, 127.1, 124.3, 76.7, 43.1,
37.7, 28.3, 27.4, 26.3, 22.4, 14.5;

MS: m/z= 429 [M+1];

Anal. Calcd for C25H28N6O : C, 70.07; H,
6.59; N, 19.61. Found: C, 70.04; H, 6.57; N, 19.58.

http://www.acgpubs.org/OC/2011/Volume%204/Issue%201/13-OC-1106-199.pdf

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HPLC condition:

Column: Alltima C18 (Alltech 88050) 15.0cm in length x 4.6mm in internal diameter and 5 micron particle size;
Column temperature: 40 C;
Solvent A: Buffer solution A 1.1 g of heptanesulfonic acid in 1 liter of water and adjust the pH to 2.5;
Solvent B: Methanol Flow rate: 1.2mL/min;
Gradient Elution Condition:
Time% A % %B
0 min 50 50
35 min 15 85
Detector: 240 nm;
Injection volume: 10 uL.

The chromatographic purity of
the compounds was analyzed using Agilent 1200 series HPLC instrument under the following conditions:
Column : Symmetry C18, 4.6 × 75 mm, 3.5 µm
Mobile phase : Eluent A: Deionized water, Eluent B: HPLC grade Methanol
Chromatographic Conditions
a. Column temperature : Ambient
b. Sample compartment : Ambient
c. Detector : 225 nm
d. Injection volume : 10 µL
e. Run time : 45 minutes
f. Flow rate :1.0 mL/min
g. Injector :Auto sampler with variable volume injector
h. Diluent : HPLC grade Acetonitrile

DUBLIN, Jan. 8, 2014 /PRNewswire/ — Actavis plc today announced that it has received approval from the U.S. Food and Drug Administration (FDA) on its Abbreviated New Drug Application (ANDA) for Telmisartan Immediate-Release Tablets, 20 mg, 40 mg and 80 mg, a generic equivalent to Boehringer Ingelheim’s Micardis. Actavis intends to launch the product immediately.

http://www.drugs.com/news/actavis-version-micardis-receives-fda-approval-49915.html?utm_source=ddc&utm_medium=email&utm_campaign=Today%27s+news+summary+-+January+8%2C+2014

MIDAZOLAM

8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine

59467-70-8 ^{CAS NO OF FREE BASE}

59467-94-6 MALEATE, Launched – 1982, Roche (Originator)

59467-96-8 (HCl)

A short-acting hypnotic-sedative drug with anxiolytic and amnestic properties. It is used in dentistry, cardiac surgery, endoscopic procedures, as preanesthetic medication, and as an adjunct to local anesthesia. The short duration and cardiorespiratory stability makes it useful in poor-risk, elderly, and cardiac patients. It is water-soluble at pH less than 4 and lipid-soluble at physiological pH.

Midazolam (/mɪˈdæzəlæm/, marketed in English-speaking countries and Mexico under the trade names Dormicum, Hypnovel, andVersed,) is a short-acting drug in the benzodiazepine class developed by Hoffmann-La Roche in the 1970s. The drug is used for treatment of acute seizures, moderate to severe insomnia, and for inducing sedation and amnesia before medical procedures. It possesses profoundly potentanxiolytic, amnestic, hypnotic, anticonvulsant, skeletal muscle relaxant, and sedative properties.^[6][7][8] Midazolam has a fast recovery time and is the most commonly used benzodiazepine as a premedication for sedation; less commonly it is used for induction and maintenance of anesthesia.Flumazenil, a benzodiazepine antagonist drug, can be used to treat an overdose of midazolam, as well as to reverse sedation.^[7] However, flumazenil can trigger seizures in mixed overdoses and in benzodiazepine-dependent individuals, so is not used in most cases.^[9][10]

midazolam

Administration of midazolam by the intranasal or the buccal route (absorption via the gums and cheek) as an alternative to rectally administereddiazepam is becoming increasingly popular for the emergency treatment of seizures in children. Midazolam is also used for endoscopyprocedural sedation and sedation in intensive care. The anterograde amnesia property of midazolam is useful for premedication before surgery to inhibit unpleasant memories. Midazolam, like many other benzodiazepines, has a rapid onset of action, high effectiveness and low toxicity level. Drawbacks of midazolam include drug interactions, tolerance, and withdrawal syndrome, as well as adverse events including cognitive impairment and sedation. Paradoxical effects occasionally occur, most commonly in children and the elderly, particularly after intravenous administration. The drug has also recently been hastily introduced for use in executions in the USA in combination with other drugs.

Midazolam is a short-acting benzodiazepine in adults with an elimination half-life of one to four hours; however, in the elderly, as well as young children and adolescents, the elimination half-life is longer. Midazolam is metabolised into an active metabolite alpha1-hydroxymidazolam. Age related deficits, renal and liver status affect the pharmacokinetic factors of midazolam as well as its active metabolite. However, the active metabolite of midazolam is minor and contributes to only 10 percent of biological activity of midazolam. Midazolam is poorly absorbed orally with only 50 percent of the drug reaching the bloodstream. Midazolam is metabolised by cytochrome P450 (CYP) enzymes and by glucuronide conjugation. The therapeutic as well as adverse effects of midazolam are due to its effects on the GABA_A receptors; midazolam does not activate GABA_A receptors directly but, as with other benzodiazepines, it enhances the effect of the neurotransmitter GABA on the GABA_A receptors (↑ frequency of Cl− channel opening) resulting in neural inhibition. Almost all of the properties can be explained by the actions of benzodiazepines on GABA_A receptors. This results in the following pharmacological properties being produced: sedation, hypnotic, anxiolytic, anterograde amnesia, muscle relaxation and anti-convulsant.Midazolam maleate is a benzodiazepine that is commercialized by Astellas Pharma and Roche as an intravenous or intramuscular injection for the long-term sedation of mechanically ventilated patients under intensive care. The drug is also available in a tablet formulation, and is currently distributed in various markets, including Germany, Japan, Switzerland and the U.K. In March 2002, two lots of a syrup formulation were recalled in the U.S. due to the potential presence of a crystalline precipitate of an insoluble complex of midazolam and saccharin. Subsequently, the injection and syrup formulations of the product were both withdrawn from the U.S. market. In 2010, a Pediatric Use Marketing Authorization (PUMA) was filed for approval in the E.U. by ViroPharma for the treatment of prolonged, acute, convulsive seizures in infants, toddlers, children and adolescents, from 3 months to less than 18 years. In 2011, a positive opinion was assigned to the PUMA and final approval was assigned in June 2011. The product was launched in the U.S. in November 2011. This product was filed for approval in Japan in 2013 by Astellas Pharma for the conscious sedation in dentistry and dental surgery. In the same year the product was approved for this indication.

In terms of clinical development, a nasal formulation of the drug is in phase III clinical trials at Upsher-Smith for rescue treatment of seizures in patients on stable anti-epileptic drug regimens who require control of intermittent bouts of increased seizure activity (seizure clusters). The Hopitaux de Paris had been developing a sublingual tablet formulation of midazolam to be used in combination with morphine for the treatment of pain in children following bone fractures; however, no recent development has been reported for this indication. NovaDel Pharma had been developing the compound preclinically for the treatment of generalized anxiety, however no recent developments have been reported.

Midazolam achieves its therapeutic effect through interaction with the gamma-aminobutyric acid benzodiazepine (GABA-BZ) receptor complex. Subunit modulation of the GABA-BZ receptor chloride channel macromolecular complex is hypothesized to be responsible for some of the pharmacological properties of benzodiazepines, which include sedative, anxiolytic, muscle relaxant, and anticonvulsive effects in animal models. GABA acts at inhibitory synapses in the brain by binding to specific transmembrane receptors in the plasma membrane of both pre- and post-synaptic neurons, opening ion channels and bringing about a hyperpolarization via either chloride or potassium ion flow.

In 2008, fast track designation was assigned to midazolam maleate in the U.S. for the treatment of seizure disorders.

In 2009, Orphan Drug Designation was received in the U.S. by for the treatment of seizure disorders in patients who require control of intermittent bouts of increased seizure activity (e.g. acute repetitive seizures, seizure clusters). This designation was assigned in the U.S. for the treatment of nerve agent-induced seizures.

In 2010, midazolam maleate was licensed to Upsher-Smith by Ikano Therapeutics for the treatment of acute repetitive seizure in patients with epilepsy. However, in 2010, Ikano closed and dissolved its business. Previously, Ikano had transferred to Upsher-Smith ownership of it nasal midazolam maleate program.

Midazolam is among about 35 benzodiazepines which are currently used medically, and was synthesised in 1975 by Walser and Fryer at Hoffmann-LaRoche, Inc in the United States.Owing to its water solubility, it was found to be less likely to cause thrombophlebitis than similar drugs.The anticonvulsant properties of midazolam were studied in the late 1970s, but not until the 1990s did it emerge as an effective treatment for convulsive status epilepticus. As of 2010, it is the most commonly used benzodiazepine in anesthetic medicine. In acute medicine, midazolam has become more popular than other benzodiazepines, such as lorazepam and diazepam, because it is shorter lasting, is more potent, and causes less pain at the injection site.Midazolam is also becoming increasingly popular in veterinary medicine due to its water solubility.

Midazolam is a water-soluble benzodiazepine available as a sterile, nonpyrogenic parenteral dosage form for intravenous or intramuscular injection. Each mL contains midazolam hydrochloride equivalent to 1 mg or 5 mg midazolam compounded with 0.8% sodium chloride and 0.01% edetate disodium with 1% benzyl alcohol as preservative, and sodium hydroxide and/or hydrochloric acid for pH adjustment. pH 2.9-3.7.

Midazolam is a white to light yellow crystalline compound, insoluble in water. The hydrochloride salt of midazolam, which is formed in situ, is soluble in aqueous solutions. Chemically, midazolam HCl is 8-chloro-6-(2-fluorophenyl)-1-methyl-4H- imidazo[1,5-a] [1,4] benzodiazepine hydrochloride. Midazolam hydrochloride has the molecular formula C₁₈H₁₃ClFN₃•HCl, a calculated molecular weight of 362.25 and the following structural formula:

In the Netherlands, midazolam is a List II drug of the Opium Law. Midazolam is a Schedule IV drug under the Convention on Psychotropic Substances. In the United Kingdom, midazolam is a Class C controlled drug. In the United States, midazolam (DEA number 2884) is on the Schedule IV list of the Controlled Substances Act as a non-narcotic agent with low potential for abuse.

midaolam hydrochloride NDA 018654, 075154

REF

U.S. Pat. No. 4,280,957

U.S. Pat. No. 5,693,795

U.S. Pat. No. 6,512,114

Midazolam Maleate
Drugs Fut 1978, 3(11): 822

Bioorganic and Medicinal Chemistry, 2012 ,  vol. 20,  18  pg. 5658 – 5667

Journal of Heterocyclic Chemistry, 1983 ,  vol. 20,  3  pg. 551 – 558.. 32 maleate

WO 2001070744

WO 2001002402

WO 2012075286

US2011/275799 A1… no 5

Journal of Organic Chemistry, 1978 ,  vol. 43, p. 936,942, mp free base, nmr

……………………….

introduction

4H-imidazo[1,5-a][1,4]benzodiazepines or, more simply, imidazobenzodiazepines, are a class of benzodiazepines having the general formula (I),

wherein the 1,4-diazepine ring is fused with a 1,3-imidazole ring. The main compounds part of the 4H-imidazo[1,5-a][1,4]benzodiazepines are Midazolam of formula (IV):

an active ingredient currently commercially available as a hydrochloride salt under the name of Versed or Hypnovel for anaesthetic and sedative use and the maleate salt currently commercially available under the name Dormicum or Flormidal.
Other important compounds are Climazolam of formula (VII):

Imidazenil of formula (VIII):

1-Hydroxymidazolam of formula (IX):

and Desmethyl midazolam of formula (X):

all these being biologically active substances and having psychotropic and sedative action.
The synthesis of the Midazolam as described in U.S. Pat. No. 4,280,957 of Hoffmann-La Roche provides for the decarboxylation reaction of the 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylic acid of formula (VI) according to the following scheme:

The process for preparing the intermediate (VI) via basic hydrolysis of the corresponding ester is described in such patent publication and it is well known in the art.
The thermal decarboxylation reaction in high boiling solvent such as mineral oil at 230° C. for 5 min results in a mixture of products of Midazolam of formula (IV) and of Isomidazolam of formula (IV-bis), a non-pharmacologically active isomer, at a 80:20 ratio. The two products are separated by chromatography.
At industrial level, the formation of the Isomidazolam isomer impurity requires a further isomerisation reaction performed on the mixture of the two compounds to convert the isomer into the active product. The reaction mixture obtained from the thermal decarboxylation is thus subjected to basic treatment under the action of KOH in EtOH followed by an acid treatment which thus provides a mixture of Midazolam-Isomidazolam at a 95:5 ratio. The final removal of the Isomidazolam impurity from the product occurs through crystallisation of the product from AcOEt and EtOH. In order to limit this isomerisation treatment, in the subsequent U.S. Pat. No. 5,693,795 of Hoffmann-La Roche dated 1999, there is described a process for performing the decarboxylation of the compound of formula (VI) in n-butanol in a continuous tubular reactor with a 4 minutes permanence period with a yield between 47-77%. However, the reaction, performed at high temperature and pressure (280° C., 100 bars) results in the formation of a considerable percentage of Isomidazolam (85:15 Midazolam/Isomidazolam ratio) which still requires the basic isomerisation step.
Lastly, in U.S. Pat. No. 6,512,114 of Abbott Laboratories there is described the decarboxylation of the compound of formula (VI) in mineral oil or in N,N-Dimethylacetamide (DMA) at 160-230° C. for at least 3 hours obtaining a 3/1 to 6/1 Midazolam/Isomidazolam ratio with a yield of isolated product equal to just 54%.
Though performed using dedicated apparatus and in extreme conditions, the prior art processes do not allow selectively performing the decarboxylation reaction of the intermediate (VI) to Midazolam thus requiring a further synthetic passage followed by crystallisation with ensuing reduction of the overall yield.

Midazolam (8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine) is represented by the following structural formula (I):

Midazolam is a central nervous system (CNS) depressant, used for short term treatment of insomnia. Like other benzodiazepines, midazolam binds to benzodiazepine receptors in the brain and spinal cord and is thus used as a short-acting hypnotic-sedative drug with anxiolytic and amnestic properties. It is currently used in dentistry, cardiac surgery, endoscopic procedures, as a preanesthetic medication, as an adjunct to local anesthesia and as a skeletal muscle relaxant. Depending on the pH value, midazolam can exist in solution as a closed ring form (I) as well as an open ring form (IA), which are in equilibrium, as shown in Scheme 1:

The amount of the open ring form (IA) is dependent upon the pH value of the solution. At a pH value of about 3, the content of the open ring form (IA) can be 40%, while at pH value of 7.5, the closed ring form (I) can be more than 90%.

Clinical studies have demonstrated that there are no significant differences in the clinical activity between midazolam hydrochloride and midazolam maleate, however the use of intravenous midazolam hydrochloride has been associated, in some cases, with respiratory depression and arrest.

U.S Pat. No. 4,280,957 (hereinafter the ’957 patent) describes a synthetic process for preparing midazolam, which is depicted in Scheme 2 below. This process includes reacting 2-aminomethyl-7-chloro-2,3-dihydro-5-(2-fluorophenyl)-1H-1,4-bezodiazepine (II) with acetic anhydride in dichloromethane to produce 2-acetamido-methyl-7-chloro-2,3-dihydro-5-(2-fluorophenyl)-1H-1,4-bezodiazepine (III). The latter is heated with polyphosphoric acid at 150° C. to produce 8-chloro-6-(2-fluorophenyl)-3a,4-dihydro-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine of formula (IV), which is purified by column chromatography. Compound IV is then mixed with toluene and manganese dioxide and heated to reflux to afford midazolam base, which is crystallized from ether to yield a product with mp of 152-154° C.

The ’957 patent further describes an alternative process which includes reacting 2-aminomethyl-7-chloro-2,3-dihydro-5-(2-fluorophenyl)-1H-1,4-bezodiazepine (II) (optionally as a dimaleate salt) with triethylorthoacetate in ethanol and in the presence of p-toluenesulfonic acid to afford 8-chloro-6-(2-fluorophenyl)-3a,4-dihydro-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine (IV). This product is dissolved in xylene and treated with activated manganese dioxide to afford the crude base, which is reacted in situ with maleic acid in ethanol and crystallized by addition of ether to produce the midazolam maleate having melting point of 148-151° C. The process is depicted in Scheme 3 below.

The preparation of midazolam maleate from the isolated midazolam base is also described in a further example of the ’957 Patent, wherein a warm solution of midazolam base in ethanol is combined with a warm solution of maleic acid in ethanol. The mixture is diluted with ether and at least part of the solvents is evaporated using a steam bath to obtain crystalline midazolam maleate having melting point of 148-151° C. The yield and the purity of the obtained midazolam maleate are not disclosed.

U.S. Pat. No. 6,512,114 (hereinafter the ’114 patent) describes another synthetic process for preparing midazolam, which is depicted in Scheme 4 below. According to this Process, the starting material 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine-3-carboxylic acid (V) is heated in mineral oil for 3 hours at 230° C. until it is decarboxylated, followed by treatment with potassium tert-butoxide, to afford midazolm (I), isomidazolam (VI) and a midazolam dimmer (VII). Midazolam base is obtained in 54.5% yield after two re-crystallizations from ethyl acetate and heptane; however, the purity of the product is not disclosed.

The preparation of midazolam by conventional routes is liable to produce impurities such as isomidazolam (VI) and a midazolam dimmer (VII), and possibly other impurities. There is, therefore, a need in the art for a midazolam purification process that will provide highly pure midazolam containing minimal amounts of impurities produced. The present invention provides such a process.

This example describes the preparation of midazolam base as taught in the ’957 patent.

16 g (0.03 mol) of 2-aminomethyl-7-chloro-5-(2-fluorophenyl)-2,3-dihydro-1H-1,4-bezodiazepine dimaleate was dissolved in 200 ml of toluene and 10 ml of 25% ammonium hydroxide solution was added and mixing was maintained for an hour. Then, the phases were separated and the toluene phase was dried by azeotropic distillation using a Dean Stark apparatus. 7 ml (0.038 mol) of triethylorthoacetate was added and the solution was heated to reflux for 4 hours, after which time the solution was left to cool to ambient temperature. 25 ml of methyl tert-butyl ether was added and the mixture was cooled overnight to produce 8-chloro-6-(2-fluorophenyl)-3a,4-dihydro-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine, which was isolated by filtration. The product was mixed with 200 ml of toluene and dried by azeotropic distillation using a Dean Stark apparatus. Then, 30 g of manganese dioxide was added and the mixture was heated to reflux for two hours. The excess manganese dioxide was filtered off to afford a solution of midazolam base in toluene, which was evaporated to obtain a product having 97.9% purity and containing 0.44% of impurity VIII and 1.14% of impurity IX (according to HPLC).

…………………………

US4280957

EXAMPLE 28

2-Aminomethyl-7-chloro-2,3-dihydro-5-(2-fluorophenyl)-1H-1,4-benzodiazepine dimaleate

A suspension of 17 g (0.05 m) of 7-chloro-1,3-dihydro-5-(2-fluorophenyl)-2-nitromethylene-2H-1,4-benzodiazepine-4-oxide in 200 ml of tetrahydrofuran and 100 ml of methanol was hydrogenated in presence of 17 g of Raney nickel at an initial pressure of 155 psi for 24 hrs. The catalyst was removed by filtration and the filtrate was evaporated. The residue was dissolved in 50 ml of 2-propanol and warmed on the steambath. A warm solution of 17 g of maleic acid in 60 ml of ethanol was added and the salt was allowed to crystallize by cooling in the ice bath. The final product consisted of yellow crystals with mp 196

EXAMPLE 14

8-Chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine

Acetic anhydride, 7 ml., was added to a solution of 6.16 g. of crude 2-aminomethyl-7-chloro-2,3-dihydro-5-(2-fluorophenyl)-1H-1,4-benzodiazepine in 200 ml. of methylene chloride. The solution was layered with 200 ml. of saturated aqueous sodium bicarbonate and the mixture was stirred for 20 minutes. The organic layer was separated, washed with sodium bicarbonate, dried over sodium sulfate and evaporated to leave 6.2 g. resinous 2-acetaminomethyl-7-chloro-2,3-dihydro-5-(2-fluorophenyl)-1H-1,4-benzodiazepine. This material was heated with 40 g. of polyphosphoric acid at 150 water, made alkaline with ammonia and ice and extracted with methylene chloride. The extracts were dried and evaporated and the residue (5.7 g.) was chromatographed over 120 g. of silica gel using 20% methanol in methylene chloride. The clean fractions were combined and evaporated to yield resinous 8-chloro-3a,4-dihydro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[ 1,5-a][1,4]benzodiazepine. A mixture of this material with 500 ml. of toluene and 30 g. of manganese dioxide was heated to reflux for 11/2 hours. The manganese dioxide was separated by filtration over celite. The filtrate was evaporated and the residue was crystallized from ether to yield a product with m.p. 152 was recrystallized from methylene chloride/hexane

EXAMPLE 49

8-Chloro-6-(2-fluorophenyl)-1-methyl-6H-imidazo[1,5-a][1,4]benzodiazepine

Potassium t-butoxide, 0.625 g. (5.5 mmol), was added to a solution of 1.625 g. (5 mmol) of 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine in 20 ml. of dimethylformamide cooled to -30 nitrogen for 10 min. at -30 ml. of glacial acetic acid and was then partitioned between aqueous bicarbonate and toluene/methylene chloride (3:1 v/v). The organic layer was separated, dried and evaporated. The residue was chromatographed over 60 g. of silica gel using 25% (v/v) methylene chloride in ethyl acetate. The less polar product was eluted first and was crystallized from ethylacetate/hexane to yield product with m.p. 180

EXAMPLE 50

8-Chloro-6-(2-fluorphenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine

Potassium t-butoxide, 0.125 g. (1.1 mmol) was added to a solution of 0.325 g. (1 mmol) of 8-chloro-6-(2-fluorophenyl)-1-methyl-6H-imidazo[1,5-a][1,4]benzodiazepine in 20 ml. of dimethylformamide cooled to -30 -30 by addition of 0.2 ml. of glacial acetic acid and was partitioned between aqueous sodium bicarbonate and methylene chloridetoluene (1:3). The organic phase was washed with water, dried and evaporated. The residue was chromatographed over 20 g. of silica gel using ethyl acetate for elution. After elution of starting material, product was collected and crystallized from ether/hexane, m.p. 156

hyd and dihydrochloride

EXAMPLE 24

8-Chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine dihydrochloride

A solution of 0.32 g (1 mmol) of 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine in 5 ml of ethanol was treated with excess ethanolic hydrogen chloride. The salt was crystallized by addition of 2-propanol and ether. The colorless crystals were collected, washed with ether and dried to leave a final product with mp 290

EXAMPLE 258-Chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine hydrochloride

A solution of 0.325 g (1 mmol) of 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine in 3 ml of ethanol was combined with a suspension of 0.4 g (1 mmol) of the dihydrochloride of this compound in 5 ml of ethanol. After filtration, the solution was treated with ether and heated on the steambath for 5 min to crystallize. The crystals were collected, washed with ether and dried to leave the monohydrochloride with mp 295

maleate

EXAMPLE 22

8-Chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine maleate

A warm solution of 6.5 g (0.02 m) of 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine in 30 ml of ethanol was combined with a warm solution of 2.6 g (0.022 m) of maleic acid in 20 ml of ethanol. The mixture was diluted with 150 ml of ether and heated on the steam bath for 3 min. After cooling, the crystals were collected, washed with ether and dried in vacuo to yield a final product with mp 148

…

Synthesis

US20110275799

Midazolam, can be described according to scheme 4 indicated below:

8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepin-3-carboxylic acid of formula (VI)was prepared according to processes known in the art (e.g. U.S. Pat. No. 4,280,957) which comprise the basic hydrolysis of the corresponding ester.
For the reactions performed in the microreactor, the solutions containing the substrates to be decarboxylated were loaded into 5 and 10 mL gastight glass syringes (Hamilton, item n. 81527, 81627) mounted on syringe pumps (KD Scientifics, model KDS100). A pipe made of PTFE® (OD=1.58 mm, ID=0.8 mm, Supelco, item n. 58696-U) was used for making the reaction channel.A counterpressure valve sold by Swagelok (item n. SS-SS1-VH) was used for regulating the flow within the channel.Example 1Synthesis of the Compound of Formula (V)—Example of the Invention

50 g (0.135 mol) of 8-chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepin-3-carboxylic acid of formula (VI) and 250 mL of ethanol were loaded into a two-neck 500 mL flask, equipped with a magnetic stirrer. 40 mL of an aqueous solution of 1 M HCl are dripped in about 10 minutes. The open di-hydrochloride intermediate of formula (V) starts precipitating into the reaction environment already after 3 minutes from the beginning of the addition of the acid solution. The mixture is maintained stirred at RT for 3 hrs and then it is filtered on buckner washing the solid with ethanol. The moist product is dried in an oven under vacuum at 60° C. up to reaching a constant weight. A light yellow crystalline product is obtained (51.5 g, 83% yield). The crude product was used for the decarboxylation without further purifications.

ESI-MS [MeCN+0.1% HCOOH]: m/z 388 (V); 370 (VI).

¹H-NMR (250 MHz, CD3OD): 2.52 (s, 3H); 4.27-4.41 (m, 2H); 7.22-8.1 (m, 7H). M.p.: 217° C.

Example 2

Synthesis of Midazolam of Formula (IV)—Performed in Batch—Example of the Invention

30 g (0.065 mol) of 5-(aminomethyl)-1-{(4-chloro-2-[(2-fluorophenyl)carbonyl]phenyl}-2-methyl-1H-imidazole-4-carboxylic acid dihydrochloride of formula (V) and 90 mL of NMP are loaded into a three-neck 250 mL flask, equipped with a magnetic stirrer and coolant. The mass is heated using an oil bath at T=195-203° C. for one hour. Thus, 1 mL of solution is collected for performing HPLC analysis. The reaction product is Midazolam having 82% titre (w/w) (determined via HPLC titre correcting it using the solvent) and it contains 1% of Isomidazolam. The product is extracted using Isopropyl acetate after raising the pH to 10 by adding aqueous Na2CO3.

Example 3

Synthesis of Midazolam of Formula (IV)—Performed in a Micro-Reactor—Example of the Invention

3.22 g (7 mmol) of 5-(aminomethyl)-1-{4-chloro-2-[(2-fluorophenyl)carbonyl]phenyl}-2-methyl-1H-imidazole-4-carboxylic acid dihydrochloride of formula (V) and 10 mL of NMP are loaded into a 10 mL flask equipped with a magnetic stirrer. In order to facilitate the complete solubilisation of the substrate, it is necessary to slightly heat the reaction mixture (about 40° C.) for a few minutes. The solution thus obtained is transferred into a 10 mL gastight glass syringe mounted on a KDS100 syringe pump (FIG. 1) and the flow is regulated at 1.0 mL/h so as to set a residence period of 30 minutes at 200° C. The reaction product is Midazolam having an 89% titre (w/w) (determined via HPLC titre correcting it using the solvent) and containing 3% (w/w) of Isomidazolam.

Example 4Synthesis of Midazolam of formula (IV)—Comparison of the InventionA table is reported which summarises the results of the decarboxylation of the compound of formula (V) and (V-bis) (for the latter see Examples 6 and 7) obtained according to some embodiments of the invention and those obtained by way of experiment through the decarboxylation of the intermediate of formula (VI) (process of the prior art) both performed in 3 volumes of NMP at 200° C., both in batch method (Example 4) and in continuous method with the microreactor (MR) made of PTFE of FIG. 1. (Examples 4-1, 4-2, 4-3).

Example	substrate	Mode	Solv.	T° C.	t min.	Midazolam (p/p)	Isomidaz. (P/P)
2	(V)	Batch	NMP	200	60	82	1
3	(V)	MR	NMP	200	30	89	3
7	(V-bis)	Batch	NMP	200	60	68	3
4	(VI)	Batch	NMP	200	60	78	18
4-1	(VI)	MR	NMP	200	38	81	17
4-2	(VI)	MR	NMP	200	20	77	18
4-3	(VI)	MR	NMP	200	15	58	22
U.S. Pat. No.	(VI)	Tubular	n-BuOH	290	4	85 *	15 *
5,693,795		reactor
U.S. Pat. No.	(VI)	Batch	Olio	230	180	75 *	25 *
6,512,114			min.			87.5 *	12.5 *
			or DMA
* = Midazolam/Isomidazolam ratio only (other impurities not considered).

The product of the comparative experiments 4, 4-1, 4-2, 4-3 and of the two USA patents should be subjected to a further isomerisation process to reduce the high amount of Isomidazolam so as to be able to obtain Midazolam free of Isomidazolam after further crystallization, which would not be required for the product obtained according to the invention (examples 2 and 3).

Preparation of 8-Chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine maleate (Midazolam Maleate)

A 4-neck RBF was charged under nitrogen flow with: 10 g of Midazolam (IV) (prepared according to example 2) and 40 mL of Ethanol. The slurry was stirred until complete dissolution at 25/30° C. In an other flask was prepared the following solution: 3.72 g of maleic acid are dissolved in 15 mL of Ethanol. The slurry was stirred until complete dissolution at 25/30° C. The maleic acid solution is dropped in 30/40 minutes and keeping T=25/30° C. into the solution containing Midazolam. The slurry was cooled down at −15° C. in one hour and kept at that temperature for at least 2 hours. The slurry was then filtered and the cake was washed with 40 mL of cool Ethanol. The filter was discharged and the product was dried at 40° C. under vacuum for 2 hours and then at 60° C. for 8 hours. 12.8 g of Midazolam Maleate as white solid were collected (Molar yield=94.5%). m.p.=149-152° C. (by DSC).

Preparation of 8-Chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine dihydrochloride (Midazolam dihydrochloride)

A 4-neck RBF was charged under nitrogen flow with: 1 g of Midazolam (IV) (prepared according to example 2) and 15 mL of Ethanol. The slurry was stirred until complete dissolution at 25/30° C. 5 mL of a ethanolic solution of Hydrochloric acid 2N were slowly added. 20 mL of Isopropanol were added over 30 minutes at RT. The slurry was cooled down at −15° C. in one hour and kept at that temperature for at least 2 hours. The slurry was then filtered and the cake was washed with 10 mL of cool isopropanol. The filter was discharged and the product was dried at 40° C. under vacuum for 2 hours and then at 60° C. for 8 hours. Midazolam dihydrochloride as white solid was collected.

MIDAZOLAM HYDROCHLORIDE

Example 10

Preparation of 8-Chloro-6-(2-fluorophenyl)-1-methyl-4H-imidazo[1,5-a][1,4]benzodiazepine hydrochloride (Midazolam hydrochloride)

A 4-neck RBF was charged under nitrogen flow with: 1 g of Midazolam (IV) (prepared according to example 2) and 10 mL of Ethanol. The slurry was stirred until complete dissolution at 25/30° C. In an other flask was prepared the following suspension: 1.22 g of Midazolam dihydrochloride (prepared according to example 9) and 15 mL of Ethanol. The Midazolam ethanolic solution was added to the Midazolam dihydrochloride suspension. After filtration, the solution was treated with MTBE and heated at 60° C. until crystallization. After cooling to RT, the slurry was filtered, the cake washed with MTBE and the product was dried to provide Midazolam (mono)hydrochloride as a white solid.

…..

Rapamycin (Sirolimus)

READ AT

http://worlddrugtracker.blogspot.in/2014/01/rapamycin-sirolimus.html

http://www.allfordrugs.com/2014/01/15/rapamycin-sirolimus-for-the-prophylaxis-of-organ-rejection-in-patients-receiving-renal-transplants/

Spironolactone

Spironolactone, Supra-puren, Suracton, спиронолактон, سبيرونولاكتون ,

螺内酯 , Abbolactone, Aldactide, SNL, Spiroctanie, Sprioderm, Verospirone,  Opianin

7α-Acetylthio-17α-hydroxy-3-oxopregn-4-ene-21-carboxylic acid γ-lactone

(1’S,2R,2’R,9’R,10’R,11’S,15’S)-9′-(acetylsulfanyl)-2′,15′-dimethylspiro[oxolane-2,14′-tetracyclo[8.7.0.0^2,7.0^11,15]heptadecan]-6′-ene-5,5′-dione

MF C₂₄H₃₂O₄S, MW 416.573 Da

Spironolactone, marketed under the brand name Aldactone among others, is a medication primarily used to treatfluid build-up due to heart failure, liver scarring, or kidney disease.^[1] Other uses include high blood pressure, low blood potassium that does not improve with supplementation, early puberty, excessive hair growth in women,^[1] and as a component of hormone replacement therapy for transgender women.^[6] It is taken by mouth.^[1]

Common side effects include electrolyte abnormalities particularly high blood potassium, nausea, vomiting, headache, a rash, and a decreased desire for sex. In those with liver or kidney problems extra care should be taken.^[1]Spironolactone has not been well studied in pregnancy and should not be used to treat high blood pressure of pregnancy.^[7] It is a steroid that blocks mineralocorticoid receptors. It also blocks androgen, and blocks progesterone. It belongs to a class of medications known as potassium-sparing diuretics.^[1]

Spironolactone was introduced in 1959.^[8][9] It is on the World Health Organization’s List of Essential Medicines, the most important medications needed in a basic health system.^[10] It is available as a generic medication.^[1] The wholesale cost in the developing world as of 2014 is between 0.02 and 0.12 USD per day.^[11] In the United States it costs about 0.50 USD per day.^[1]

Medical uses

Spironolactone is used primarily to treat heart failure, edematous conditions such as nephrotic syndrome or ascites in people with liver disease, essential hypertension, hypokalemia, secondary hyperaldosteronism (such as occurs with hepatic cirrhosis), and Conn’s syndrome (primary hyperaldosteronism). On its own, spironolactone is only a weak diuretic because it primarily targets the distal nephron (collecting tubule), where only small amounts of sodium are reabsorbed, but it can be combined with other diuretics to increase efficacy.

Spironolactone is an antagonist of the androgen receptor (AR) as well as an inhibitor of androgen production. Due to the antiandrogenic effects that result from these actions, it is frequently used off-label to treat a variety of dermatological conditions in which androgens, such as testosterone and dihydrotestosterone (DHT), play a role. Some of these uses include androgenic alopecia in men (either at low doses or as a topical formulation) and women, and hirsutism, acne, and seborrhea in women.^[12] Spironolactone is the most commonly used drug in the treatment of hirsutism in the United States.^[13] Higher doses of spironolactone are not recommended in males due to the high risk of feminization and other side effects. Similarly, it is also commonly used to treat symptoms of hyperandrogenism in polycystic ovary syndrome.^[14]

Spironolactone (SL) is known to be a potent aldosterone antagonist at mineralocorticoid steroid hormone receptors, and it is widely used in humans for the treatment of essential hypertension, congestive heat failure and refractory edema or hyperaldosteronism. However, the prolonged use of SL is associated with undesirable endocrine side effects such as gynecomastia and lose of libido in men and menstrual irregularities in women due to interaction of SL with gonadal steroid hormone biosynthesis and target cell gonadal steroid receptors.

The nature and prevalence of the undesirable side effects limit the usefulness of spironolactone as a therapeutic agent. Gynecomastia or tender breast enlargement has been found to occur in 10% of hypertensive patients using spironolactone for therapy as compared to 1% of men in the placebo group. Recent studies by Pitt, et al. with spironolactone have shown that in patients with congestive heart failure (CHF) taking digoxin and a loop diuretic—spironolactone therapy in conjunction with digitalis and ACE inhibitor—reduces mortality by 30%. See Pitt, B., et al., The Effect of Spironolactone on Morbidity and Mortality in Patients with Severe Heart Failure, Randomized Aldactone Evaluation Study Investigors; N. Engl. J. Med., 1999, 341:709-717. These authors stated that the 30% reduction in the risk of death among patients in the group receiving spironolactone could be attributed to a lower risk of both death from progressive heart failure and sudden death from cardiac arrhythmic causes. In addition, they found that the frequency of hospitalization for worsening heart failure is 35% lower in the spironolacotone treated group than in the placebo group. These authors concluded that patients who received spironolactone had a significant improvement in the symptoms of severe heart failure caused by systolic left ventricular dysfunction. Overall, 8% of the patients in the spironolactone group discontinued treatment because of adverse events. The purpose of the present invention is to make available the individual chiral isomers of spironolactone that would be effective in treating CHF and in reducing hypertension, and at the same time would be devoid of undesirable side effects such as gynecomastia, lose of libido in men, and menstrual irregularities in women.

Spironolactone is the name commonly used for a specific spirolactone that has the full chemical name 17-hydroxy-7-alpha-mercapto-3-oxo-17-alpha-pregn-4-ene-21-carboxylic acid gamma-lactone acetate. The term “spirolactone” denotes that a lactone 10 ring (i.e., a cyclic ester) is attached to another ring structure in a spiro configuration (i.e., the lactone ring shares a single carbon atom with the other ring). Spirolactones that are coupled to steroids are the most important class of spirolactones from a pharmaceutical perspective, so they are widely referred to in the pharmaceutical arts simply as spirolactones. As used herein, “spironolactone” refers to a molecule comprising a lactone structure coupled via a spiro configuration to a steroid structure or steroid derivative.

Spironolactone, its activities, and modes of synthesis and purification are described in a number of U.S. patents, notably U.S. Pat. Nos. 3,013,012, 4,529,811 and 4,603,128.

Intracellular receptors (IRs) form a class of structurally-related genetic regulators that act as ligand-dependent transcription factors. See Evans, R. M., “The Steroid and Thyroid Hormone Receptor Superfamily”, Science, May 13, 1988; 240(4854):889-95. Steroid receptors are a recognized subset of the IRs, including the progesterone receptor (PR), androgen receptor (AR), estrogen receptor (ER), which can be referred to collectively as the gonadal steroid receptors, glucocorticoid receptor (GR), and mineralocorticoid receptor (MR). Regulation of a gene by such factors requires both the IR itself and a corresponding ligand that has the ability to selectively bind to the IR in a way that affects gene transcription.

Ligands for the IRs can include low molecular weight native molecules, such as the hormones aldosterone, progesterone, estrogen and testosterone, as well as synthetic derivative compounds such as medroxyprogesterone acetate, diethylstilbesterol and 19-nortestosterone. These ligands, when present the fluid surrounding a cell, pass through the outer cell membrane by passive diffusion and bind to specific IR proteins to create a ligand/receptor complex. This complex then translocates to the cell’s nucleus, where it binds to a specific gene or genes present in the cell’s DNA. Once bound to DNA, the complex modulates the production of the protein encoded by that gene. In this regard, a compound that binds to an IR and mimics the effect of the native ligand is referred to as an “agonist”, while a compound that binds to an IR and inhibits the effect of the native ligand is called an “antagonist”.

The therapeutic mechanism of action of spironolactone involves binding to intracellular mineralocorticoid receptors (MRs) in kidney epithelial cells, thereby inhibiting the binding of aldosterone. Spironolactone has been found to counteract the sodium reabsorption and potassium excretion effects of aldosterone and other mineralocorticoids. Spironolactone has also been shown to interfere with testosterone biosynthesis, has anti-androgen action and inhibits adrenal aldosterone biosynthesis. Large doses of spironolactone in children appear to decrease the testosterone production rate.

Spironolactone is found to exhibit intra-individual variability of pharmacokinetic parameters and it presumably belongs to the group of drugs with high inter-subject variability. Spironolactone has poor water solubility and dissolution rate.

In order to prolong the half-life and decrease the side effects associated with spironolactone, syntheses of spironolactone derivatives have been developed (e.g. synthesis of mexrenone, prorenone, spirorenone). Slight modifications of the spironolactone steroid skeleton, e.g. such as formation of 11β-allenic and epoxy compounds, have been shown to effect important variations in the affinity and specificity for the mineralocorticoid receptor. These results suggest that it is possible to develop spironolactone analogues that do not interact with the androgen receptor or cytochrome P-450 and are therefore free of spironolactone undesirable side-effects.

METABOLISM

SYNTHESIS

METHOD 1 REF 150

REF 130, 150

METHOD 2 REF 140

METHOD 3 REF 150

Synthesis

Cella, John A.; Tweit, Robert C. (1959). Journal of Organic Chemistry 24: 1109. doi:10.1021/jo01090a019.

(See also part 1 and part 3)

SPECTROSCOPY UV

SPECTROSCOPY IR

KBR

The principal absorption peaks of the spectrum shown in Figure 5 were noted at 1765,
1693, 1673, 1240, 1178, 1135, 1123 and 1193 cm -1.

SPECTROSCOPY 1H NMR

SPECTROSCOPY 13C NMR

SPECTROSCOPY MASS SPECTRUM

130 J.A. Cola, E.A. Brown, and R.R. Burtner, 3. Org. Chem., 24, 1109(1959).

 140 Remington’s: The Science and Practice of Pharmacy, 19 t~ edn.Volume II, K.G. Alfonso, ed.; Mack Publishing Co., Pennsylvania (1995) p.1048.
150. G. Anner and H. Wehrli (Ciba-Geigy, A.-G.), German Often 2,625,723 (cl.C07J21/00), Dec,1976; Swiss Appl. 75/7, 696, 13Jun. 1975; pp. 37.

ANALYTICAL

• High-Performance Liquid Chromatographic Conditions
  Column	LiChrosorb RP-8, 5 μm. 150 × 4.6 mm I.D.
  Eluent	Acetonitrile-0.05 M phosphate buffer, pH 4 (45:55)
  Flow-rate	1 ml/min
  Temperature	25° C.
  Detector	UV detector, wavelength 286 nm or 271 nm
  Recorder	Chart speed 0.5 cm/min
  Sample loop	10 μl

• The concentration of canrenone is determined in plasma and urine samples by high-performance liquid chromatography (HPLC) with UV-detection. An aliquot of 300 ng of spironolactone derivative is added to the samples as internal standard, which are then extracted twice with 1 ml n-hexane-toluene (1:1, v/v). The organic phase is taken to dryness and re-dissolved in 250 μl HPLC eluent (methanol-water, 60:40, v/v). (25×4.6 mm; 5 μm). Detection is performed with the UV detector set at λ=285 nm.

Flurometric Method

Five ml of water is a reagent blank and 5 ml of working standards containing 0.05 μg and 0.20 μg of SC-9376 are carried through the entire procedure. Lower sales are read vs. the 0.05 μg standard at full scale, and higher samples vs. the 0.20 μg standard. Fluorescence readings are proportional to the concentrations of the standards in this range.

Pipette 0.2 ml of heparinized plasma into a 50-ml polyethylene-stoppered centrifuge tube, dilute to 5 ml with water and add 15 ml of methylene chloride (Du Pont refrigeration grade, redistilled). Shake for 30 seconds, centrifuge and discard the aqueous supernatant. Add 1 ml 0.1 N NaOH, shake 15 seconds, centrifuge and discard the supernatant. Transfer a 10-ml aliquot of the methylene chloride phase to another tube containing 2 ml of 65% aqueous sulfuric acid, shake 30 seconds, centrifuge and remove organic phase by aspiration. The material is allowed to stand at room temperature for about 1 hour and then about 1 ml of the sulfuric acid phase in transferred to a quartz cuvette. Fluorescence intensity is determined in an Aminco-Bowman spectrophotofluorometer (activation maximum, 465 nm).

Gas Liquid Chromatography

The GLC estimation is carried out on a Fractovap Model 251 series 2150 (Carlo Erba) instrument equipped with a Nickel-63 electron capture detector. A 6-foot, 0.4 mm internal diameter, U-shaped glass column, packed with OV-17 2% or XE-60 1% on gas chrom A, 100-120 mesh (Applied Science Lab) is conditioned for 3 days before use. Argon with 10% methane which passed through a molecular sieve before entering the column is used as the carrier gas. The conditions of analysis are: column 255° C., detector 275° C., carrier gas flow 30 ml/min. Samples are injected on the column with a 10 μl Hamilton syringe. The injector in not heated.

PATENT

https://www.google.com/patents/US20090325918

EXAMPLE 1Chiral Separation

The separation of 7 beta isomer of SL is schematically described below.

• Chromatographic Method for Isolation of SL Isomers

  The basic method is described in Chan, Ky, et al., J. Chromatog, Nov. 15, 1991:571 (1-2) 291-297. The separation is performed using spectra-physics HPLC instrument and UV variable wavelength detector set at 254 nm. For chiral separation, the chromatographic column is either a pre-packed 25 mm×4.6 mm ID Cyclobond 1 (5 μm particle size), or a pre-packed 150 mm×4 mm ID Resolvosil BSA-7 column (5 μm) operated using the conditions described herein.

  Analysis of the isomers present in the peaks in the chromatograms and their chiral extract purity analysis can be determined in each case by high resolution NMR spectroscopy using a chiral shift reagent. Based on this information and the determination of molecular weight by mass spectrometry and/or optical activity, structural configuration is assigned to each isomer. Eluted samples of isomers may be re-chromatographed in order to obtain adequate quantities of isomers having desired optical purity for study. For future use, reference standards that are optically pure will be compared for confirmation of purity and identity to the isolated isomers that are obtained after their chromatographic separation.

EXAMPLE 2Chemical Synthesis of Optical Isomers

As an example, the desire spironolactone 7-beta-isomer is synthesized following the scheme that is described below:

• Diene (i) is prepared from commercially available starting materials using methods well known in the art of chemical synthesis.
  Diene (i) is treated with acetic acid and the mixture is heated to reflux to yield 7-alpha-acetate ester (ii). The 7-alpha-ester (ii) is further subjected to nucleophilic substitution, followed by hydrolysis to obtain the 7-beta-isomer (iii). The 7-beta-isomer (iii) is then esterified with an acyl halide in the presence of a base to generate the desired spironolactone 7-beta-isomer (iv).

EXAMPLE 3Preparation of Radiolabeled Probe Compounds of the Invention

Using known methods, the compounds of the invention may be prepared as radiolabeled probes by carrying out their synthesis using precursors comprising at least one atom that is a radioisotope. The radioisotope is preferably selected from at least one of carbon (preferably

¹⁴

C), hydrogen (preferably

³

H), sulfur (preferably

³⁵

S), or iodine (preferably I). Such radiolabeled probes are conveniently synthesized by a radioisotope supplier specializing in customer synthesis of radiolabeled probe compounds. Such suppliers include Amersham Corporation, Arlington Heights, Ill.; Cambridge Isotope Laboratories, Inc., Andover, Mass.; SRI International, Menlo Park, Calif.; Wizard Laboratories, West Sacramento, Calif.; ChemSyn Laboratories, Lexena, Kans.; American Radiolabeled Chemicals, Inc., St. Louis, Mo.; and Moravek Biochemicals Inc., Brea, Calif.

Tritium labeled probe compounds are also conveniently prepared catalytically via platinum-catalyzed exchange in tritiated acetic acid, acid-catalyzed exchange in tritiated trifluoroacetic acid, or heterogeneous-catalyzed exchange with tritium gas. Tritium labeled probe compounds can also be prepared, when appropriate, by sodium borotritide reduction. Such preparations are also conveniently carried out as a custom radiolabeling by any of the suppliers listed in the preceding paragraph using the compound of the invention as substrate.

EXAMPLE 4Isolation and Purification Procedure

The optical isomers of spironolactones may be isolated from fluid sample such as urine or blood as follows:

Extraction from Urine

The urine sample is extracted with dichloromethane and the extract washed with NaOH (0.1 N) and then with water to neutrality. The residue obtained after evaporation of the dichloromethane extract is purified on TLC in three different systems: benzene-acetone-water, (150:100:0.4); chloroform-ethanol, (90:10); ethyl acetate-cyclohexane-ethanol, (45:25:10), using aldosterone as reference standard.

The extract is then purified by high performance liquid chromatography (HPLC) on a Waters 6000 A, 480 U.V. detector instrument with radial pressure. The extract is first run through a C

₁₈

10μ column using methanol-water (70:30) as the eluent, followed by a silica 5μ column using dichloromethane-methanol (95:5). In both cases, the rate of the eluent is 1.5 ml/min. A small part of the extract is subjected to heptafluorobutyrylation for GLC investigation.

References

Spironolactone

Systematic (IUPAC) name
7α-Acetylthio-17α-hydroxy-3-oxopregn-4-ene-21-carboxylic acid γ-lactone
Clinical data
Pronunciation	/spɪˌroʊnəˈlæktoʊn, spaɪ–, spə–, –ˈrɒ–, –noʊ–/or /ˌspaɪrənoʊˈlæktoʊn/[2][3][4]
Trade names	Aldactone
AHFS/Drugs.com	Monograph
MedlinePlus	a682627
Pregnancy category	AU: B3 US: C (Risk not ruled out)
Routes of administration	Oral[1]
Legal status
Legal status	UK: POM (Prescription only) US: ℞-only
Pharmacokinetic data
Protein binding	90%+[5]
Metabolism	Hepatic CYP450
Biological half-life	1.3-2 hours
Excretion	Urine, bile
Identifiers
CAS Number	52-01-7
ATC code	C03DA01 (WHO)
PubChem	CID 5833
IUPHAR/BPS	2875
DrugBank	DB00421
ChemSpider	5628
UNII	27O7W4T232
KEGG	D00443
ChEBI	CHEBI:9241
ChEMBL	CHEMBL1393
Chemical data
Formula	C24H32O4S
Molar mass	416.574 g/mol

///////Spironolactone, Supra-puren, Suracton, спиронолактон, سبيرونولاكتون ,

螺内酯 , Abbolactone, Aldactide, SNL, Spiroctanie, Sprioderm, Verospirone,  Opianin

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