| abstract |
NEW MATERIAL:A compound shown by the formula I (R1 is 1-4C alkyl; R2 is aminocarbonyl, carboxyl, 1-4C alkyl, or 5-7C cycloalkyl; R3 is 1-4C alkyl, or H; R4 is H, or F) and its salt. EXAMPLE:1-Ethyl-6-fluoro-7-[ 3-(aminocarbonyl)-1-piperazinyl ]-4-oxo-1,4-dihydroquinoline-3-carboxylic acid. USE:Having a wide antibacterial action on Gram-positive and Gram-negative bacteria, extremely useful as a drug. PREPARATION:A 7-halogeno-6-fluoro-4-oxo-1,4-dihydroquinoline-3-carboxylic acid derivative shown by the formula II (X is Cl, or F) is reacted with a piperazine derivative shown by the formula III in a solventless state of in a solvent such as butanol, etc. at room temperature -200 deg.C, to give a compound shown by the formula I . |