[go: up one dir, main page]

AP216A - Improved method for synthesis. - Google Patents

Improved method for synthesis. Download PDF

Info

Publication number
AP216A
AP216A APAP/P/1991/000274A AP9100274A AP216A AP 216 A AP216 A AP 216A AP 9100274 A AP9100274 A AP 9100274A AP 216 A AP216 A AP 216A
Authority
AP
ARIPO
Prior art keywords
omeprazole
phase
reaction mixture
compound
aqueous phase
Prior art date
Application number
APAP/P/1991/000274A
Other versions
AP9100274A0 (en
Inventor
Arne Elof Brandstrom
Original Assignee
Ab Astra
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Ab Astra filed Critical Ab Astra
Publication of AP9100274A0 publication Critical patent/AP9100274A0/en
Application granted granted Critical
Publication of AP216A publication Critical patent/AP216A/en

Links

Classifications

    • CCHEMISTRY; METALLURGY
    • C07ORGANIC CHEMISTRY
    • C07DHETEROCYCLIC COMPOUNDS
    • C07D401/00Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom
    • C07D401/02Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings
    • C07D401/12Heterocyclic compounds containing two or more hetero rings, having nitrogen atoms as the only ring hetero atoms, at least one ring being a six-membered ring with only one nitrogen atom containing two hetero rings linked by a chain containing hetero atoms as chain links

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Plural Heterocyclic Compounds (AREA)
  • Pharmaceuticals Containing Other Organic And Inorganic Compounds (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
  • Feeding, Discharge, Calcimining, Fusing, And Gas-Generation Devices (AREA)

Abstract

Omeprazole is obtained by reacting

Description

Technical field
The present invention relates to an improved method for the synthesis of 5-methoxy-2-[[(4-methcxy-3,5-dimethyl-2pyridinyl)-methyl]sulfinyl-lH-benizimidazoie, referred to under its generic name omeprazole throughout the following specification and claims.
Prior art
US-A-4 255 431 discloses a process for the synthesis of omeprazole comprising the steps of reacting 5-methoxy-2[ ( 4-methoxy-3,5-dimethyl-2-pyridinyl)-methyithio]-1Hbenzimidazole in a methylene chloride solution with mchloroperoxybenzoic acid resulting in the formation of omeprazole and m-chlorobenzoic acid, omeprazole is highly sensitive to acids, and the reaction mixture has to be maintained at a low temperature to prevent excessive decomposition in the reaction mixture.
The product is worked-up by filtering-off of m-chlorobenzoic acid formed during the reaction. The filtrate is diluted with methylene chloride, is extiacted with ^200^ solution, dried and evaporated. The resultinq omeprazole product is contaminated with starting materials and byproducts .
Summary of the invention
The object of the present invention is to provide an improved method for the synthesis of omeprazole, which eliminates the drawbacks of previously known methods.
This object is achieved according to the present inven-
BAD ORIGINAL
AP 0 0 0 2 1 6 »
tion, which is characterized by the steps of reacting 5methoxy-2-[(4-methoxy-3,5-dimethy1-2-pyridinyl)-methylthioj-ΙΗ-benzimidazole (below denoted Compound I) with mchloroperoxybenzoic acid in a methylene chloride solution at a substantially constant pE of about 8.0 to 8.6; extracting the reaction with aqueous NaCH; separating the aqueous phase from the organic phase; and adding an alkyl formate to the aqueous phase, resulting in crystallization of omeprazole.
The m-chloroperoxybenzoic acid is suitably used in an amount of 0.7 - 1.4 molar equivalents of Compound I, and preferably in an amount of 0.9 - 1.2 molar equivalents.
According to one embodiment of the invention, the alkyl formate is methylformate or ethylformate, methylformate being preferred.
The alkyl formate is suitably used in an amount of 1.2 2.0 molar equivalents of Compound I, and preferably in an amount of 1.5 - 1.8 molar eqv.ivalents.
One important feature of the method according to the invention is that unreacted sulfide is not transferred into the aqueous phase upon the extraction with aqueous NaOH. Another important feature is that m-chlorobenzoic acid does not crystallize upon the addition of methylformate to the aqueous phase, thereby eliminating the need of filtering-off of m-chlcrobenzoic acid in a previous step.
The pH of the reaction mixture may be maintained within the pH range of 8.0 - 8.6 with the aid of pH static titration with NaOH or with the. use of a buffer. Preferred buffers are sodium bicarbonate and potassium bicarbonate.
BAD ORIGINAL A
AP 0 0 0 2 1 6 f
it
A great advantage of the method according to the invention is that the reaction takes place in the organic methylene chloride phase while the m-chlorobenzoic acid formed during the reaction goes into the aqueous phase containing the buffer, in the case a buffer is used. Because of this, omeprazole formed does not stay in contact with the acid and the reaction may be performed at a temperature above 0°C.
According to one embodiment of the invention the pH of the aqueous NaCH phase is kept at above about 12.
According to another embodiment of the invention the crystallization of omeprazole is performed at a pH of above 9.
The invention will be further illustrated below with a non-limiting example.
Example
5-methoxy-2-[ ( 4-rnethoxy-3,5-dimethyl-2-pyridinyl) methylthio]-lH-benzimidazole (16.2 g; 0.0492 mol) is reacted with m-chlcroperoxybenzoic acid (13.6 g; 0.0537 mol) in CH2C12 acting as a solvent at a pH of 8.6, which is maintained by the presence of KHCO^ (5.6 g; 0.056 mol) acting as a buffer. The temperature is maintained at about 0°C during the addition.
Diluted NaOH is added to a pH above 12 and the CH2C12 phase is separated off.
Methylformate (1.7 g) is charged to the water phase and the pH is kept above 9, whereupon omeprazole crystallizes. The crystals are filtered off and are washed with water and methanol at a temperature of about 0°C. The washed crystals are dried under vacuum. Yield: 15.6 g (92 %).

Claims (11)

1. A method for the synthesis of omeprazole comprising reacting 5-methoxy-2-[(4-methoxy-3,5-dimethyl-2-pyridinyl) methylthio J-ΙΗ-benzimidazole (Compound I) with m-chloropercxybenzoic acid in a methylene chloride solution at a substantially constant pH of about 3.0 to 8.6; extracting the reaction mixture with aqueous NaOH; separating the aqueous phase from the organic phase; and adding an alkyl formate to the aqueous phase; whereby omeprazole crystallises from the aqueous phase.
2. Method according to claim 1, wherein the m-chloroperoxybenzoic acid is used in an amount of 0.7 1.4, preferably 0.9 - 1.2, molar equivalents of Compound I.
3. Method according to claim 1 or 2, wherein the alkyl formate is methyl formate .
4. Method according to any one of the preceding claims wherein the pH of the reaction mixture is maintained within the pH range of 8.0 - 8.6 by means of pH static titration with NaOH.
5. Method according to any one of the preceding claims wherein the pH of the reaction mixture is maintained within the pH range of 8.0 - 8.6 with the use of a buffer.
6. Method according to claim 5, wherein the buffer is sodium bicarbonate or potassium bicarbonate.
7. Method according to any one of the preceding claims wherein the pH of the aqueous NaOH phase is kept at above about 12.
BAD ORIGINAL $
AP Ο Ο Ο 2 1 6
8. Method according to any one of the preceding claims wherein the alkyl formate is added in an amount of 1.2 2.0, preferably 1.5 - 1.8, molar equivalents of Compound I.
9. Method according to any one of the preceding claims
5 wherein the omeprazole crystallises at a pH of above 9.
10. Method according to claim 1 substantially as hereinbefore described.
11. Omeprazole when obtained by a method according to any one of'the preceding claims.
bad original $
APAP/P/1991/000274A 1990-06-07 1991-06-07 Improved method for synthesis. AP216A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
SE9002043A SE9002043D0 (en) 1990-06-07 1990-06-07 IMPROVED METHOD FOR SYNTHESIS

Publications (2)

Publication Number Publication Date
AP9100274A0 AP9100274A0 (en) 1991-07-31
AP216A true AP216A (en) 1992-09-02

Family

ID=20379708

Family Applications (1)

Application Number Title Priority Date Filing Date
APAP/P/1991/000274A AP216A (en) 1990-06-07 1991-06-07 Improved method for synthesis.

Country Status (41)

Country Link
US (1) US5386032A (en)
EP (1) EP0533752B1 (en)
JP (1) JP2993122B2 (en)
KR (1) KR0178045B1 (en)
CN (1) CN1040536C (en)
AP (1) AP216A (en)
AT (1) ATE162790T1 (en)
AU (1) AU640246B2 (en)
BG (1) BG61265B1 (en)
CA (1) CA2083605C (en)
CZ (1) CZ279928B6 (en)
DE (1) DE69128832T2 (en)
DK (1) DK0533752T3 (en)
DZ (1) DZ1504A1 (en)
EG (1) EG19392A (en)
ES (1) ES2113378T3 (en)
FI (1) FI102967B (en)
GR (1) GR3026642T3 (en)
HR (1) HRP920770B1 (en)
HU (1) HU214323B (en)
IE (1) IE911845A1 (en)
IL (1) IL98274A (en)
IS (1) IS1752B (en)
LT (1) LT3584B (en)
LV (1) LV10271B (en)
MA (1) MA22171A1 (en)
NO (1) NO300541B1 (en)
NZ (1) NZ238224A (en)
PL (1) PL165433B1 (en)
PT (1) PT97873B (en)
RO (1) RO111366B1 (en)
RU (1) RU2061693C1 (en)
SA (1) SA91120027B1 (en)
SE (1) SE9002043D0 (en)
SG (1) SG48053A1 (en)
SK (1) SK278505B6 (en)
TN (1) TNSN91042A1 (en)
UA (1) UA32524C2 (en)
WO (1) WO1991018895A1 (en)
YU (1) YU47570B (en)
ZA (1) ZA913779B (en)

Families Citing this family (62)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
SE521100C2 (en) * 1995-12-15 2003-09-30 Astra Ab Process for the preparation of a benzimidazole compound
US6489346B1 (en) 1996-01-04 2002-12-03 The Curators Of The University Of Missouri Substituted benzimidazole dosage forms and method of using same
US5840737A (en) 1996-01-04 1998-11-24 The Curators Of The University Of Missouri Omeprazole solution and method for using same
US6699885B2 (en) 1996-01-04 2004-03-02 The Curators Of The University Of Missouri Substituted benzimidazole dosage forms and methods of using same
US6645988B2 (en) * 1996-01-04 2003-11-11 Curators Of The University Of Missouri Substituted benzimidazole dosage forms and method of using same
SE508669C2 (en) * 1996-04-26 1998-10-26 Astra Ab New procedure
SK283805B6 (en) 1996-09-09 2004-02-03 Slovakofarma, A. S. Method of omeprazole preparation
SE510666C2 (en) * 1996-12-20 1999-06-14 Astra Ab New Crystal Modifications
CA2204580A1 (en) * 1997-05-06 1998-11-06 Michel Zoghbi Synthesis of pharmaceutically useful pyridine derivatives
US6437139B1 (en) 1997-05-06 2002-08-20 Pdi-Research Laboratories, Inc. Synthesis of pharmaceutically useful pyridine derivatives
KR100463031B1 (en) * 1997-05-26 2005-04-06 동아제약주식회사 New preparation method of 5-methoxy-2- [3,5-dimethyl-4-methoxypyridylmethyl) sulfinyl] -1H-benzimidazole
SE510650C2 (en) * 1997-05-30 1999-06-14 Astra Ab New association
SE510643C2 (en) * 1997-06-27 1999-06-14 Astra Ab Thermodynamically stable omeprazole sodium form B
ES2137862B1 (en) * 1997-07-31 2000-09-16 Intexim S A ORAL PHARMACEUTICAL PREPARATION INCLUDING A COMPOUND OF ANTI-ULCER ACTIVITY AND PROCEDURE FOR ITS OBTAINING.
US6096340A (en) * 1997-11-14 2000-08-01 Andrx Pharmaceuticals, Inc. Omeprazole formulation
US6174548B1 (en) 1998-08-28 2001-01-16 Andrx Pharmaceuticals, Inc. Omeprazole formulation
SE9704183D0 (en) 1997-11-14 1997-11-14 Astra Ab New process
SI20019A (en) * 1998-07-13 2000-02-29 LEK, tovarna farmacevtskih in kemi�nih izdelkov, d.d. An improved process for synthesis of 5-methoxy-2-/(4-methoxy-3,5-dimethyl-2-pyridyl)methyl/ sulphynyl-1h-benzimidazol
US6191148B1 (en) 1998-08-11 2001-02-20 Merck & Co., Inc. Omerazole process and compositions thereof
US6166213A (en) * 1998-08-11 2000-12-26 Merck & Co., Inc. Omeprazole process and compositions thereof
US6733778B1 (en) 1999-08-27 2004-05-11 Andrx Pharmaceuticals, Inc. Omeprazole formulation
UA72748C2 (en) * 1998-11-10 2005-04-15 Astrazeneca Ab A novel crystalline form of omeprazole
IL142703A (en) 1998-11-10 2006-04-10 Astrazeneca Ab Crystalline form of omeprazole
US6362202B1 (en) 1999-03-02 2002-03-26 Sepracor Inc. Methods and compositions using (−) norcisapride in combination with proton pump inhibitors or H2 receptor antagonists
US6353005B1 (en) 1999-03-02 2002-03-05 Sepracor, Inc. Method and compositions using (+) norcisapride in combination with proton pump inhibitors or H2 receptor antagonist
US6268385B1 (en) 1999-08-26 2001-07-31 Robert R. Whittle Dry blend pharmaceutical formulations
US6316020B1 (en) 1999-08-26 2001-11-13 Robert R. Whittle Pharmaceutical formulations
US6780880B1 (en) 1999-08-26 2004-08-24 Robert R. Whittle FT-Raman spectroscopic measurement
US6369087B1 (en) 1999-08-26 2002-04-09 Robert R. Whittle Alkoxy substituted benzimidazole compounds, pharmaceutical preparations containing the same, and methods of using the same
US6312712B1 (en) 1999-08-26 2001-11-06 Robert R. Whittle Method of improving bioavailability
US6326384B1 (en) 1999-08-26 2001-12-04 Robert R. Whittle Dry blend pharmaceutical unit dosage form
US6262086B1 (en) 1999-08-26 2001-07-17 Robert R. Whittle Pharmaceutical unit dosage form
US6262085B1 (en) 1999-08-26 2001-07-17 Robert R. Whittle Alkoxy substituted Benzimidazole compounds, pharmaceutical preparations containing the same, and methods of using the same
US6312723B1 (en) 1999-08-26 2001-11-06 Robert R. Whittle Pharmaceutical unit dosage form
RU2247120C2 (en) * 1999-10-28 2005-02-27 Грюненталь Гмбх Method for preparing anti-ulcerous therapeutic agents
DE19951960C2 (en) 1999-10-28 2002-06-27 Gruenenthal Gmbh Process for the preparation of benzimidazole derivatives suitable as ulcer therapeutics
JP2004524303A (en) 2001-02-02 2004-08-12 テバ ファーマシューティカル インダストリーズ リミティド Method for producing substituted 2- (2-pyridylmethyl) sulfinyl-1H-benzimidazoles
KR100783020B1 (en) * 2001-03-23 2007-12-07 동아제약주식회사 2-Methylchloride Pyridine Derivative and Preparation Method of Benzimidazole Derivative Using the Same
CA2450433C (en) * 2001-07-16 2010-05-25 Janssen Pharmaceutica N.V. Improved process for preparing benzimidazole-type compounds
JP2005521662A (en) * 2002-01-25 2005-07-21 サンタラス インコーポレイティッド Transmucosal delivery of proton pump inhibitors
SE0203092D0 (en) 2002-10-18 2002-10-18 Astrazeneca Ab Method for the synthesis of a benzimidazole compound
WO2004073654A2 (en) * 2003-02-20 2004-09-02 Santarus, Inc. A novel formulation, omeprazole antacid complex-immediate release for rapid and sustained supression of gastric acid
US8993599B2 (en) * 2003-07-18 2015-03-31 Santarus, Inc. Pharmaceutical formulations useful for inhibiting acid secretion and methods for making and using them
MXPA06000529A (en) * 2003-07-18 2006-08-11 Santarus Inc Pharmaceutical composition for inhibiting acid secretion.
CA2531566C (en) * 2003-07-18 2013-05-07 Santarus, Inc. Pharmaceutical formulation and method for treating acid-caused gastrointestinal disorders
US20070292498A1 (en) * 2003-11-05 2007-12-20 Warren Hall Combinations of proton pump inhibitors, sleep aids, buffers and pain relievers
US8815916B2 (en) * 2004-05-25 2014-08-26 Santarus, Inc. Pharmaceutical formulations useful for inhibiting acid secretion and methods for making and using them
US8906940B2 (en) * 2004-05-25 2014-12-09 Santarus, Inc. Pharmaceutical formulations useful for inhibiting acid secretion and methods for making and using them
EP2264025B1 (en) 2004-09-13 2013-11-06 Takeda Pharmaceutical Company Limited Method for producing lansoprazole
WO2006040635A1 (en) * 2004-10-11 2006-04-20 Ranbaxy Laboratories Limited Processes for the preparation of substituted sulfoxides
KR100641534B1 (en) 2005-07-28 2006-11-01 한미약품 주식회사 Method for preparing esomeprazole and salts thereof
EP2998288B1 (en) 2005-12-01 2022-08-24 ACADIA Pharmaceuticals Inc. Substituted phenethylamines with serotoninergic and/or norepinephrinergic activity
EP1801110A1 (en) 2005-12-22 2007-06-27 KRKA, tovarna zdravil, d.d., Novo mesto Esomeprazole arginine salt
WO2007129328A2 (en) * 2006-05-09 2007-11-15 Cadila Healthcare Limited Process for preparing 2-[pyridinyl]sulfinyl-substituted benzimidazoles
US20090092658A1 (en) * 2007-10-05 2009-04-09 Santarus, Inc. Novel formulations of proton pump inhibitors and methods of using these formulations
EP2114919A2 (en) 2007-01-31 2009-11-11 Krka Tovarna Zdravil, D.D., Novo Mesto Process for the preparation of optically pure omeprazole via salt formation with a chiral amine or treatment with an entiomer converting enzyme and chromatographic seperation
DK2125698T3 (en) 2007-03-15 2016-11-07 Auspex Pharmaceuticals Inc Deuterated d9-VENLAFAXINE
CN102066396B (en) * 2008-03-31 2014-03-12 科学与工业研究委员会 Pharmaceutical composition for use as antigastric secretory or antiulcer agent
WO2010134099A1 (en) 2009-05-21 2010-11-25 Cadila Healthcare Limited One pot process for preparing omeprazole and related compounds
CN102786513A (en) * 2011-05-18 2012-11-21 中国医学科学院药物研究所 Omeprazole crystal E substance, its preparation method and its applications in medicines and healthcare products
WO2013108068A1 (en) 2012-01-21 2013-07-25 Jubilant Life Sciences Limited Process for the preparation of 2-pyridinylmethylsulfinyl benzimidazoles, their analogs and optically active enantiomers
US12364721B2 (en) 2019-09-24 2025-07-22 Prolacta Bioscience, Inc. Compositions and methods for treatment of inflammatory and immune diseases

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3404610A1 (en) * 1983-02-11 1984-08-16 Aktiebolaget Hässle, Mölndal BENZIMIDAZOLE DERIVATIVES, METHOD FOR THE PRODUCTION THEREOF AND MEDICINAL PRODUCTS CONTAINING THE SAME
EP0197013A1 (en) * 1985-03-01 1986-10-08 Aktiebolaget Hässle Substituted benzimidazoles for the manufacture of a medicament for treatment of intestinal inflammatory diseases
EP0242341A1 (en) * 1986-02-14 1987-10-21 Aktiebolaget Hässle Benzimidazoles, process for their preparation and preparations containing same

Family Cites Families (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
IN148930B (en) * 1977-09-19 1981-07-25 Hoffmann La Roche
SE7804231L (en) * 1978-04-14 1979-10-15 Haessle Ab Gastric acid secretion
US4307102A (en) * 1981-02-19 1981-12-22 Sterling Drug Inc. Phenanthro[2,3-c]pyrazole
ZW4585A1 (en) * 1984-04-19 1985-11-20 Hoffmann La Roche Imidazole derivatives
IL76839A (en) * 1984-10-31 1988-08-31 Byk Gulden Lomberg Chem Fab Picoline derivatives,processes for the preparation thereof and pharmaceutical compositions containing the same
FI91754C (en) * 1986-12-02 1994-08-10 Tanabe Seiyaku Co An analogous method for preparing an imidazole derivative useful as a medicament
DE3722810A1 (en) * 1987-07-10 1989-01-19 Hoechst Ag SUBSTITUTED BENZIMIDAZOLES, METHOD FOR THE PRODUCTION THEREOF, THE PHARMACEUTICAL PREPARATIONS CONTAINING THEM AND THE USE THEREOF
SE9002206D0 (en) * 1990-06-20 1990-06-20 Haessle Ab NEW COMPOUNDS
NZ244301A (en) * 1991-09-20 1994-08-26 Merck & Co Inc Preparation of 2-pyridylmethylsulphinylbenzimidazole and pyridoimidazole derivatives from the corresponding sulphenyl compounds

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3404610A1 (en) * 1983-02-11 1984-08-16 Aktiebolaget Hässle, Mölndal BENZIMIDAZOLE DERIVATIVES, METHOD FOR THE PRODUCTION THEREOF AND MEDICINAL PRODUCTS CONTAINING THE SAME
GB2174988A (en) * 1983-02-11 1986-11-19 Haessle Ab Intermediates for pyridyl alkylthio-benzimidazole derivatives
EP0197013A1 (en) * 1985-03-01 1986-10-08 Aktiebolaget Hässle Substituted benzimidazoles for the manufacture of a medicament for treatment of intestinal inflammatory diseases
EP0242341A1 (en) * 1986-02-14 1987-10-21 Aktiebolaget Hässle Benzimidazoles, process for their preparation and preparations containing same

Also Published As

Publication number Publication date
HK1003831A1 (en) 1998-11-06
NO924682L (en) 1992-12-04
TNSN91042A1 (en) 1992-10-25
HU9203855D0 (en) 1993-03-29
HU214323B (en) 1998-03-02
HUT63408A (en) 1993-08-30
GR3026642T3 (en) 1998-07-31
YU99291A (en) 1993-11-16
NZ238224A (en) 1993-11-25
AP9100274A0 (en) 1991-07-31
IL98274A (en) 1995-03-30
EP0533752B1 (en) 1998-01-28
DK0533752T3 (en) 1998-06-02
MA22171A1 (en) 1991-12-31
PL165433B1 (en) 1994-12-30
CN1058211A (en) 1992-01-29
FI925529A0 (en) 1992-12-04
US5386032A (en) 1995-01-31
CN1040536C (en) 1998-11-04
SK278505B6 (en) 1997-08-06
FI102967B1 (en) 1999-03-31
LV10271B (en) 1995-04-20
RU2061693C1 (en) 1996-06-10
HRP920770B1 (en) 2000-06-30
EP0533752A1 (en) 1993-03-31
HRP920770A2 (en) 1995-12-31
CA2083605A1 (en) 1991-12-08
AU640246B2 (en) 1993-08-19
NO300541B1 (en) 1997-06-16
LTIP1711A (en) 1995-07-25
ATE162790T1 (en) 1998-02-15
UA32524C2 (en) 2001-02-15
SE9002043D0 (en) 1990-06-07
ES2113378T3 (en) 1998-05-01
IS3711A7 (en) 1991-12-08
ZA913779B (en) 1992-02-26
DE69128832D1 (en) 1998-03-05
CZ279928B6 (en) 1995-08-16
FI925529L (en) 1992-12-04
SG48053A1 (en) 1998-04-17
BG61265B1 (en) 1997-04-30
DZ1504A1 (en) 2004-09-13
JPH05507699A (en) 1993-11-04
SA91120027B1 (en) 2002-06-03
IS1752B (en) 2000-07-21
PT97873B (en) 1998-10-30
KR0178045B1 (en) 1999-03-20
BG97146A (en) 1993-12-24
EG19392A (en) 1995-06-29
JP2993122B2 (en) 1999-12-20
LV10271A (en) 1994-10-20
AU8080791A (en) 1991-12-31
LT3584B (en) 1995-12-27
NO924682D0 (en) 1992-12-04
WO1991018895A1 (en) 1991-12-12
FI102967B (en) 1999-03-31
IL98274A0 (en) 1992-06-21
PT97873A (en) 1992-04-30
RO111366B1 (en) 1996-09-30
YU47570B (en) 1995-10-03
DE69128832T2 (en) 1998-05-28
CS172691A3 (en) 1992-01-15
CA2083605C (en) 1998-12-08
IE911845A1 (en) 1991-12-18

Similar Documents

Publication Publication Date Title
AP216A (en) Improved method for synthesis.
AU704422B2 (en) Method for the synthesis of a benzimidazole compound
NO20010677D0 (en) Improved omeprazole method and preparations prepared therefrom
KR840007733A (en) Process for preparing C-20- and C-23-modified macrolide derivatives
KR840005124A (en) Method for preparing new substituted (+)-cyanidan-3-ol derivatives
HK1003831B (en) Improved method for synthesis
KR100632521B1 (en) Method for preparing heterocyclic compound
WO2003062223A1 (en) A method of eliminating sulfone analog in the synthesis of pyridine-benzimidazole sulfoxides
EP0115323A2 (en) Process for producing heterocyclic compound having nitromethylene group as the side chain group
JP2997035B2 (en) Method for producing porphyrin alkali salt
JO1707B1 (en) Improved method for synthesis
TH26860A (en) Improved method for synthesis
TH16348B (en) Improved method for synthesis
KR840004421A (en) Process for preparing 4- (substituted alkyl) -N- (1,3-dithiolane-2-ylidene) aniline