Process for the preparation of 9-fluoro-10-(4-methyl-1-piperazinyl)-7-oxo-2,3-dihydro-7H-pyrido¬1,2,3-de ¬1,4 benzothiazine-6-carboxylic acid hydrochloride

摘要

Process for the preparation of 9-fluoro-10-(4-methyl-1-piperazinyl)-7-oxo-2,3-dihydro-7H-pyrido [1,2,3-de][1,4]benzothiazine-6-carboxylic acid hydrochloride (Rufloxacin) of formula (I) by reaction of 2,3,5-trifluoro-4-(4-methyl-1-piperazinyl)benzoyl ethyl acetate of formula (II) with N,N-dimethylformamide dimethylacetal, followed by reaction with 2-aminoethanethiol, intramolecular cyclization by treatment with NaH, hydrolysis with H2O and salification with HCl.