体系pH值对利福霉素恶嗪环合反应的影响

Effect of System pH Value on the Rifamycin Oxazine Cyclization Reaction

基于利福平合成反应中间体利福霉素恶嗪的环合反应机制,考察反应体系的pH值对利福霉素恶嗪纯度的影响,以及调节反应体现的pH值对环合反应的温度、时间、合成利福霉素恶嗪和终产品利福平纯度和收率的影响,确定环合反应体系最佳pH值范围在5-7范围时,可以使环合反应的温度从60℃降低到55℃,反应时间由2 h缩短到1.5 h,并可以抑制副反应的发生,提高利福霉素恶嗪和终产品利福平的纯度和收率。

Based on the cyclization reaction mechanism of intermediate rifamycin oxazine in synthesis of rifampicin, effect of pH value on purity of rifamycin oxazine was investigated as well as influences of regulating pH on cyclization reaction temperature, cyclization reaction time , purity and yield of fifamycin oxazine and rifampicin. The best pH value was determined to be from 5 to 7, under this condition side reaction can be restrained , purity and yield of rifamyein oxazine and rifampiein influence can be improved.