| abstract |
The present invention relates to the novel quinolone carboxylic acid derivatives of formula (I) and their pharmaceutically acceptable salts and their hydrates. In said formula, X is a hydrocarbon, fluorocarbon or nitrogen atom, Y is a hydrogen or methyl group, R1 is a hydrogen or alkyl group having 1 to 5 carbon atom, R2 is (a) (wherein A and B are a fluorocarbon or nitrogen atom, provided that, if A=CF, B=N and if A=N, B=CF) and R3 is (b) (wherein R4 is an amino group which makes a racemate or (S)-enantiomer) or (c) (wherein R?5, R6 and R7¿ are respectively hydrogen or alkyl group having 1 to 3 carbon atom). The quinolone carboxylic acid derivative of formula (I) is prepared by the condensation of the compound of formula (II) and the compound of formula HR3 in a solvent in the presence of an acid-acceptor or an excess of the compound of formula HR3 which is a reactant; and the solvent is selected from the group consisting of pyridine, acetonitrile and N,N-dimethylformamide. In formula (II) and HR3 X, Y, Z, R?1, R2 and R3¿ are each as described. The compounds according to the present invention are used for antibacterial agent. |