[Synthesis and antibacterial activities of 1-amino-6-fluoro-1,4-dihydro-4-oxo-7-(substituted) piperazinyl-3-quinolinecarboxylic acids and their derivatives].

The title compounds 6-24 were obtained by the reaction of 5 with corresponding benzaldehydes. 5 was prepared with ethyl 7-chloro-6-fluoro-1,4-dihydro-4-oxo-3- quinolinecarboxylate by hydrolysis, amination and condensation with piperazine. Anti-bacterial activities of 5-24 were tested in vitro.