利福昔明合成工艺的研究

Research on synthesis of rifaximin

以利福霉素S和2-氨基-4-甲基吡啶为原料,二氯甲烷为溶剂,碘为催化剂,亚硫酸钠为还原剂,合成一种新药利福昔明。结果表明,优化工艺条件为:利福霉素S与催化剂碘的摩尔比为3∶1,2-氨基-4-甲基吡啶与利福霉素S的摩尔比为2.5∶1,反应温度为30℃,反应时间为24 h。在该优化条件下,产品的产率达85.2%。

A new-type drug, rifaximin was synthesized with rifamycin S and 2-amino-4-methyl-pyridine in the presence of iodine as catalyst and sodium sulfite as reducing agent, the reaction is carried out in di- chloromethane. The result showed that the optimum reaction conditions were determined as follows：the molar ratio of rifamycin S to iodine of 3： 1, the molar ratio of 2-amino-4-methyl-pyridine to rifamycin S of 2.5： 1, reaction temperature of 30 ℃, reaction time of 24 h. Under the optimum condition, the yield of the product reached 85.2%.