Pyridonecarboxylic Acids as Antibacterial Agents. VI. Synthesis and Structure-Activity Relationship of 7-(Alkyl, Cycloalkyl, and Vinyl)-1-cyclopropyl-6-fluoro-4-quinolone-3-carboxylic Acids

Abstract

The title compounds (1a-i) have been synthesized starting with ethyl 1-cyclopropyl-6, 7-difluoro-4-quinolone-3-carboxylate (2). The 7-cyclopropyl and 7-vinyl derivatives (1e and 1i) exhibited potent in vitro antibacterial activities against both gram-positive and gram-negative bacteria, being equipotent with ciprofloxacin (CPFX) except for the activity against Pseudomonas aeruginosa. The two compounds were significantly less toxic than CPFX in terms of convulsion-induction as determined by intracerebral administration to mice, but showed lower urinary recoveries on intravenous administration.