Method for preparing (S)-pantoprazole sodium

The invention discloses a method for preparing (S)-pantoprazole sodium. The method is characterized by including the steps of firstly, allowing 5-difluoromethoxy-2-[[(3,4-dimethoxy-2-pyridyl)methyl]sulfur]-1H-benzimidazole to have contact reaction with dimethyl dioxirane in an organic solvent under nitrogen protection and in the presence of an L-glutamic acid derivative to obtain (S)-pantoprazole; secondly, allowing the (S)-pantoprazole obtained in the first step to have reaction with sodium methoxide to obtain the (S)-pantoprazole sodium. The method is mild in condition, short in reaction time, high in (S)-pantoprazole sodium yield, high in selectivity and suitable for large-scale industrial production. 本发明公开了种制备(S)-泮托拉唑钠的方法，其特征在于，该方法包括：1)氮气保护下，在L-谷氨酸衍生物存在下，将5-二氟甲氧基-2-[[(3,4-二甲氧基-2-吡啶基)甲基]硫]-1H-苯并咪唑与二甲基二氧杂环丙烷在有机溶剂中进行接触反应得到得到(S)-泮托拉唑；2)将步骤1)得到的(S)-泮托拉唑与甲醇钠进行反应得到(S)-泮托拉唑钠。本发明提供的制备(S)-泮托拉唑钠的方法条件温和、反应时间短，并且(S)-泮托拉唑钠收率高，选择性高，适合用于大规模工业化生产。