Research on antibacterial and antifungal agents. XI. New antibacterial quinolones related to pirfloxacin.

The synthesis and antimicrobial activities against Gram-positive and Gram-negative bacteria of some 1-substituted quinolones related to pirfloxacin are reported. Compounds with a benzyl moiety at 1-position were generally found to be less active than the analogues bearing an unsaturated alkyl chain at the same position. Introduction of fluorine or chlorine in the benzyl moiety did not increase the antibacterial activity. All derivatives here reported were inferior to pirfloxacin as regards antibacterial power, but always superior in comparison with nalidixic acid and pipemidic acid against Gram-positive microorganisms.