6-FLUORO-1,4-DIHYDRO-4-OXO-7-SUBSTITUTED PIPERAZINYLQUINOLINE-3-CARBOXYLIC ACID DERIVATIVE

摘要

NEW MATERIAL:A compound expressed by formula I (R1 is lower alkyl; R2 and R4 are different H or CH3; R3 is H or lower alkyl; R5 is H or F) and a pharmacologically acceptable salt thereof. EXAMPLE:7-( 3,5-Dimethyl-1-piperazinyl )-1-ethyl-6-fluoro-1, 4-dihydro-4-oxoquinoline-3-carboxylic acid hydrochloride. USE:An antimicrobial agent useful as a medicine having wide antimicobial action on Gram-positive and Gram-negative bacteria. PREPARATION:(a) A compound expressed by formula II (X is Cl or F) is reacted with a compound expressed by formula III without or in a solvent or (b) a compound expressed by formula IV is reacted with a compound expressed by the formula R6CHO (R6 is H or lower alkyl) in the presence of formic acid. Alternatively, (c) the compound expressed by formula IV is reacted with a compound expressed by the formula R3A (A is halogen) in a solvent to afford the aimed compound expressed by formula I.