[Synthesis and antibacterial action of 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-aroylthiocarbamoyl-1-piperaziny l)-3-quinoline carboxylic acids].

Thirteen new 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-aroyl-thiocarbamoyl- 1 piperazinyl)-3-quinoline carboxylic acids were prepared, Their structures were characterized by elemental analysis, IR, HNMR and MS spectra.Preliminary pharmacological tests indicated that some of compounds Ia～m possess strong inhibiting activity against Escherichia coli, Bacillus subtilis and Proteus at concentration of 100 μg/ml.