Synthesis and evaluation of antibacterial activity of novel 3-methyl-1H-indazole derivatives

Aim of the study was designed to synthesize and evaluate antibacterial activity of novel heterocyclic compounds, 3-methyl-1H-indazole derivatives. The heterocyclic compounds, 3-methyl-1H-indazole derivatives (1a-1d and 2a-2d) were synthesized; all of them characterized physically by melting point, R_f value, appearance & solubility; and some of them characterized spectroscopically by IR and ¹H NMR spectroscopy. All the synthesized derivatives were evaluated for their antibacterial activity against both Gram positive bacteria, Bacillus subtilis and Gram negative bacteria, Escherichia coli by cup plate method using ciprofloxacin as a standard drug. All the synthesized heterocyclic compounds, 3-methyl-1H-indazole derivatives (1a-1d and 2a-2d), had shown antibacterial activity against the B. subtilis and E. coli. Compound 1d i.e., 1-(2-(piperidin-1-yl)ethan-1-oyl)-3-methyl-1H-indazole at the concentration of 300 ​μg/ml showed best antibacterial activity against the bacteria B. subtilis and E. coli as compared to standard drug, ciprofloxacin. The methodology for the synthesis of heterocyclic compounds, 3-methyl-1H-indazol-1-yl derivatives was simple as well as economical and gave better yield of the synthesized compounds. The compound, 1-(2-(piperidin-1-yl)ethan-1-oyl)-3-methyl-1H-indazole had shown best antibacterial activity against the bacteria B. subtilis and E. coli.