| abstract |
The present invention relates to quinolonecarboxylic acid derivatives having more excellent and broad antibacterial activities than the existing quinolone-series antibiotics. More specifically, it pertains to novel quinolonecarboxylic acid derivatives represented by formula (1), which have a derivative of 7-[8-(alcoxyimino)-2,6-diazaspiro[3,4]oct-6-yl] as a substituent, and pharmaceutically acceptable salts and isomers thereof; wherein A is C-H, C-F, C-Cl, C-O-CH3 or N; Y is H or amino; R1 is cyclopropyl or 2,4-difluorophenyl; R2 is C1-4 alkyl; and R3 is H or C1-4 alkyl. |