Preparation method for pantoprazole sodium oxynitride impurity

• Main Authors: QIN CHUNXIA, ZHANG ZHAOZHEN, WU KE, LI BAOYONG, DONG TINGHUA
• Format: Patent
• Language: English
• Published: 02.12.2015
• Subjects: CHEMISTRY; HETEROCYCLIC COMPOUNDS; METALLURGY; ORGANIC CHEMISTRY

The present invention discloses a preparation method for a pantoprazole sodium oxynitride impurity. The preparation method comprises the following steps: 2-chloromethyl-3,4-dimethoxypyridine hydrochloride is used as a raw material to react with 5-difluoromethoxy-2-mercapto-1H-benzimidazole and produce 5-difluoromethoxy-2-{[(3,4-dimethoxy-2-pyridyl)methyl]sulphur}-1H-benzimidazole; then in a presence of hydrogen peroxide and acetic acid, with copper hydroxyphosphate as a catalyst, oxidation is performed to obtain an oxynitride product of the pantoprazole; and finally a sodium salt is obtained by a reaction with sodium hydroxide, and pantoprazole sodium oxynitride impurity is obtained. According to the preparation method, no extreme reaction condition is needed, and raw materials are easy to obtain; the oxidant is capable of selective oxidations, which can not only oxidate pyridine ring, but also can oxidate thioether to sulfoxide, and by controlling the dosage of the catalyst, i.e., copper hydroxyphosphate, a peroxidation is less likely to occur (oxidate thioether to sulphone); and a post-treatment is simple and easy in operation, and the resulting product is high in purity and high in yield.