| abstract |
The present invention relates to the novel pyridonecarboxylic acid derivatives of formula (I) and to their pharmaceutically acceptable steroisomers and salts. Wherein R1, R2, R3 and R4 may be the same or different and independently represent hydrogen or lower alkyl, X represents oxygen or sulfur, Y represents hydrogen or methyl, and n denotes an integer that can be 0 and 1 compounds of the formula (I ) that has a broad antibacterial spectrum and has strong antibacterial activity against both Gram-positive and Gram-negative bacteria. The present invention also relates to processes for preparing those compounds. |