| 摘要 |
<p>The present invention relates to novel quinolone derivatives of formulae (I), (III) and (IV) having a broad antibacterial spectrum and to processes for preparing the same: wherein X1 represents hydrogen, amino group, chloro, fluoro, or methyl; X2 represents hydrogen or halogen; Y1 and Y2 each represent hydrogen, or lower alkyl (C1-3) group; R1 represents ethyl, cyclopropyl, halogen(F, Cl)-substituted cyclopropyl or halogen-substituted phenyl; R2 represents hydrogen, methyl, ethyl or t-butoxycarbonyl; R3 and R4 each represent hydrogen, nitro group, methoxycarbonyl group, ethoxycarbonyl group or nitryl group; and A represents nitrogen atom, methyn group, fluoromethyn group, chloromethyn group, methoxymethyn group, or methylmethyn group.</p> |
