PROCESS FOR THE PREPARATION OF QUINOLINE CARBOXYLIC ACIDS

摘要

The invention relates to a new process for the preparation of compounds of the general Formula I <IMG> /I/ /wherein R stands for piperazinyl, 4-methyl-piperazinyl or 4-ethyl-piperazinyl group/ and pharmaceutically acceptable salts thereof which comprises reacting a compound of the general Formula II <IMG> /II/ /wherein R1 and R2 stand for halogen, for an aliphatic acyloxy group containing 2 to 6 carbon atoms and optionally substituted by halogen, or for an aromatic acyloxy group containing 7 to 11 carbon atoms/ with a piperazine derivative of the general Formula /III/ <IMG> /wherein R3 stands for hydrogen, methyl or ethyl/ or a salt thereof and subjecting the compound of the general Formula IV <IMG> /IV/ thus obtained /wherein R, R1 and R2 are as stated above/ to hydrolysis after or without isolation and if desired converting the compound of the general Formula I thus obtained into a salt thereof or setting free the same from its salt. The compounds of the general Formula I are known antibacterial agents. The advantage of the present invention is that it makes the desired compounds of the general Formula I available in a simple manner, with high yields and in a short reaction time.