New quinoline derivatives, their preparation and therapeutic compositions containing the same

摘要

The invention relates to new quinoline derivatives of the formula: <IMAGE> I wherein R stands for C2H5, C2H4F, CH2-O-CH2-CH2OH, <IMAGE> +TR <IMAGE> to a process for their preparation comprising reacting, for 12-24 hours, at 70 DEG -95 DEG C., in dimethylformamide, the 1,4-dihydro- 3-ethoxycarbonyl- 6,8- difluoro-4-oxo-quinoline with an excess of RX (2-5 mol of RX for one mol of quinoline), in the presence of K2CO3 and subsequently hydrolyzing the obtained 3-ester by HCl under reflux conditions and to pharmaceutical compositions comprising at least one 1,4-dihydro- 3-carboxy- 6,8-difluoro- 1-R-4-oxo-quinoline derivative in admixture with a pharmaceutically acceptable diluent or carrier.