[EN] AN IMPROVED PROCESS FOR THE PREPARATION OF PANTOPRAZOLE AND ITS PHARMACEUTICALLY ACCEPTABLE SALTS<br/>[FR] PROCÉDÉ AMÉLIORÉ DE PRÉPARATION DE PANTOPRAZOLE ET DE SES SELS PHARMACEUTIQUEMENT ACCEPTABLES
申请人:MSN LAB LTD
公开号:WO2008001392A2
公开(公告)日:2008-01-03
[EN] The present invention related to an improved process for the preparation of Pantoprazole sodium sesquihydrate comprising the reaction of 5-difluoromethoxy-2-mercapto benzimidazole with 2-chloromethyl-3,4-dimethoxy pyridine hydrochloride in an aqueous alkali, which upon oxidation with sodium hypochlorite having pH of about 8.5-9.0 and assay of about 3.0-3.5 in chloro solvent followed by reaction with sodium hydroxide in acetone. The invention also relates to the process for the preparation of pantoprazole sodium sesquihydrate form-I. [FR] L'invention concerne un procédé amélioré de préparation de pantoprazole sodium sesquihydrate consistant à faire réagir un 5-difluoromethoxy-2-mercapto benzimidazole avec un 2-chloromethyl-3,4-dimethoxy pyridine hydrochloride en présence d'un alcali aqueux, à effectuer une oxydation à l'aide d'un hypochlorite de sodium présentant un pH d'environ 8,5-9,0 et un dosage d'environ 3,0-3,5 dans un solvant chloro, puis à le faire réagir avec un hydroxyde de sodium dans de l'acétone. L'invention concerne également un procédé de préparation d'un pantoprazole sodium sesquihydrate de forme I.
A chemoselective demethylation method for various methoxypyridine derivatives has been developed. Treatment of 4-methoxypyridine with L -selectride in THF for 2 h at reflux temperature afforded 4-hydroxypyridine in good yield; no reaction to anisole occurred. The utility of our method was demonstrated by the efficient synthesis of the metabolic substances of the antiulcer agent omeprazole. Chemoselective