ABSTRACT
The aim of the work is to improve the synthetic process of dexrabeprazole sodium,enhance quality and yield of the product,simplify synthetic steps,and offer a stable and feasible process. Starting from 2-[[[4-(3-methoxypropoxy)-3-methylpyridine-2-yl]methyl]thio]-1 H-benzimidazole,dexrabeprazole was produced by asym-metric oxidation reaction with oxidant cumene hydroperoxide in the presence of chiral catalyst tetraisopropyl titan-ate and L-(+)-tartaric acid diethyl ester. Dexrabeprazole sodium was obtained by the reaction of purified dexrabeprazole with sodium hydroxide in a total yield of 79%with an HPLC purity of ＞99. 5%. The structure of dexrabeprazole sodium was confirmed by NMR,IR,elemental analysis and LC-MS. The improved process of dexrabeprazole sodium possesses simple operations,good yield and high purity,which is feasible for industrializa-tion.
ABSTRACT
Esomeprazole sodium is a widely used proton pump inhibitor which is mainly applied to the treatment of gastric ul-cer,duodenal ulcer,digestive esophagitis and gastritis. By reviewing the literature over the past decade on the asymmetric oxidation of esomeprazole sodium ,the paper summarizes the synthetic process and focuses on the comparison of the critical steps. To choose suit-able chiral catalyst to reduce the cost of synthesis of esomeprazole sodium,this paper compares beyond the yield,enantioselectivity and other aspects. The conclusion is that the catalysts used in the most of oxidation systems are with a large load and high cost ,and compared with the classical Kagan-Modena system,the Ti-salan catalyst has advantages in the synthesis of esomeprazole sodium,and can be widely used.