利福昔明的合成研究

摘要

以利福霉素S、液溴、2-氨基-4-甲基吡啶、抗坏血酸（VC）为主要原料，经过溴化、环合、还原三个步骤制备了利福昔明。结果表明，最优工艺条件为：溴化反应采用乙醇和水溶剂体系，利福霉素S与溴的摩尔比为1∶1.2；环合反应中3-Br-利福霉素S与2-氨基-4-甲基吡啶的摩尔比为1∶1.6，反应温度为63℃。在该优化条件下，产品总收率达85.1%。%In this paper, rifaximin was prepared with rifamycin S, bromine, 2-amino-4-methylpyridine and vitamin C as the main raw material, via three steps of bromination, cyclization and reduction. The result showed that the optimum reaction conditions were determined as follows: In reduction, the solvent was ethanol/water and the molar ratio of rifamycin S to bromine of 1∶1.2. In cyclization, the molar ratio of ri-famycin S to 2-amino-4-methyl-pyridine of 1∶1.6 and the reaction temperature is 60℃. Under the optimum condition, the yield of the product reached 85.1%.