abstract |
Novel 4-oxoquinoline-3-carboxylic acid compounds of the formula: <IMAGE> [1] wherein R1 is cyclopropyl which may have 1 to 3 substituents of alkyl and halogen; phenyl which may be substituted by 1 to 3 substituents of alkoxy, halogen and OH; alkyl which may be substituted by halogen, alkanoyloxy or OH; alkenyl; or thienyl, R2 is 5- to 9-membered saturated or unsaturated heterocyclic ring which may be sustituted, R3 is alkyl or halogen, R4 is alkyl or halogen, R is H or alkyl, R1 and R3 may be taken together to form <IMAGE> wherein R31 is H or alkyl, and X is halogen, provided that R3 and R4 are not simultaneously halogen, and salts thereof, said compounds having excellent antimicrobial activity and hence being useful as an antimicrobial agent, and a pharmaceutical composition containing said compound as an active ingredient. |