Synthesis and Antibacterial Activity of Azetidinonyl Norfloxacin Congeners

Some novel Schiff bases and azetidinone congeners of norfloxacin have been synthesized and screened for antibacterial activity. The structures of compounds 1-ethyl-6-fluoro-7-piperazinyl-4-oxo-3-(substitutedarylidinylcarboxy- hydrazido)quinolines (2-6) and 1-ethyl-6-fluoro-7-pipera-zinyl-4-oxo-3-(3′-choloro-2′-oxo-4′-substitutedaryl-3′-aze-tidinyl)-aminocarboxy quinolines (7-11) were established by spectral and elemental analysis. The compounds 2-11 were evaluated in vitro against various strains of bacteria: E. coli ATCC 25922, B. subtilis ATCC 1633 and S. aureus ATCC 25923 to determine their antibacterial activity and feasible structure-activity relationships. The results of the study were compared with reference drug. Compound 8: 1-ethyl-6-fluoro-7-piperazinyl-4-oxo-3-(3′-choloro-2′-oxo-4′-(4′′-methoxyphenyl)-3′-azetidinyl)-aminocarboxyquinoline has displayed more potent antibacterial activity as compared to standard drug, chloramphenicol.