Optically active ofloxacin derivs. - with increased antimicrobial activity and reduced toxicity

摘要

derivs. of formula (VI) are new: X1 = halo; R1 = 1-4C alkyl; R3 = 1-3C alkyl. Also claimed are H-substd. benzoxazine derivs. of formula (X): each of X1 and X2 = halo, Q = H or a gp. of formula (a): R2 = substd. sulphonyl, alkoxycarbonyl or aralkyloxycarbonyl; Specifically claimed S(-)-9-fluoro-3-methyl-10-(4-methyl-1-piperazinyl)-7- oxo-2,3-dyhydro-7H -pyrido(1,2,3-de)(1,4) benzoazine-6-carboxylic acid (Ia) and the corresp. 10-(4-1-piperazinyl) cpd.