Synthesis of new series of 1-Aryl-1,4-dihydro-4-oxo-6-methyl pyridazine-3-carboxylic acid as potential antibacterial agents.

New series of 1-aryl-1,4-dihydro-4-oxo-6-methyl pyridazine-3-carboxylic acid has been synthesized and the structures of the new compounds were established on the basis of 1H-NMR, mass (ES/MS), elemental analysis and IR spectral data. In vitro antibacterial activity (MIC activity) was evaluated and compared with standard drugs ciprofloxacin, sparfloxacin and trovafloxacin. Most of the compounds in the series have shown very interesting antibacterial activity against both gram-positive and gram-negative organisms. In this paper, we describe studies leading to identification of antibacterial agents incorporating novel pyridazine ring surrogate. In a gratifying result, the initial pyridazine-3-carboxylic acid analogues prepared were found to exhibit in vitro antibacterial activity approaching that of corresponding fluoroquinolone progenitor.