ONE-STEP SYNTHESIZING METHOD OF LEVOFLOXACIN AND OFLOXACIN

摘要

The present invention provides a one-step synthesizing method of levofloxacin and ofloxacin. S-9,10-difluoro-2,3-dihydro-3-methyl-7-oxygen-7H-pyrido[1,2,3-Delta]-[1,4]-benzoxazine-6-carboxylic acid ester or 9,10-difluoro-2,3-dihydro-3-methyl-7-oxygen-7H-pyrido[1,2,3-Delta]-[1,4]-benzoxazine-6-carboxylic acid ester is adopted as a raw material to react with alkali in an organic solvent or water or a mixed solvent of an organic solvent and water, to obtain a corresponding carboxylic acid salt; the solvent is directly removed by evaporation after a hydrolysis process; the product is directly added into N-methylpiperazine in the form of a carboxylic acid salt; and a piperazine condensation reaction is carried out to obtain levofloxacin or ofloxacin. The method is easy to operate. A process of hydrolysis and acid adjustment is not necessary. The reaction cost is reduced, the production period is short, pollution is reduced, and the raw material utilization rate is high. The method is economical and simple, and the yield and purity of obtained levofloxacin and ofloxacin are high.