左旋氧氟沙星合成的新工艺研究

介绍了一种新的合成氟喹诺酮抗菌药左旋氧氟沙星的方法。以2，3，4，5-四氟苯甲酸为原料，经酰氯化后与N，N-二甲氨基丙烯酸乙酯偶联，S-（＋）-2-氨基丙醇置换、环合水解后与N-甲基哌嗪缩合制得，总收率为52．3％。与老工艺相比，新起始原料N，N-二甲氨基丙烯酸乙酯的应用缩减了丙二酸二乙酯缩合、部分水解脱羧及原甲酸三乙酯缩合三步反应。本合成工艺原料易得，操作简单，光学纯度好，产品收率高，有较好的工业应用前景。

Study on New Process of Synthesizing Levofloxacin

New process for preparing the fluoroquinolone antibacterial drug levofloxacin was described. The object compound was prepared from 2,3,4,5-tetrafluorobenzoic acid, via acyl chlorination, ethyl N,N-dimethylaminoacrylate coupling, S-(+)-2-aminopropanol displacement, cyclization, hydrolysis, and finally N-methylpiperazine condesation, the total yield is 52.3%. Comparing to the old process conventionally used at present, the application of the new starting material ethyl N, N-dimethylaminoacrylate can curtail three reaction steps, they are the diethyl malonate condensation, partial hydrolysis decarboxylation and triethylorthoformate condensation. New process has many advantages, such as simple procedure, short reaction period, high optical purity, cheaper raw material,higher yield. So it should have a good prospect for industrial application.