Synthesis and antibacterial evaluation of some new 4-substituted-3-aryl-1- (2,6-dimethylpyrimidin-4-yl)pyrazoles

摘要

Synthesis of a series of new 4-substituted-3-aryl-1-(2,6-dimethylpyrimidin- 4-yl)pyrazoles (2a-g, 3a-g, and 4a-g) is described. All the synthesized compounds were evaluated in vitro for their antibacterial activity against two gram-positive and two gram-negative bacteria, namely, Bacillus subtilis (MTCC 8509), Bacillus stearothermophilus (MTCC 8508), Escherichia coli (MTCC 51), and Pseudomonas putida (MTCC 121), and their activity was compared with two commercial antibiotics, streptomycin and chloramphenicol. Two compounds, namely, 3-(4-anisyl)-1-(2,6-dimethylpyrimidin-4-yl)pyrazole-4-carboxaldehyde (2b) and 3-(2-thienyl)-1-(2,6-dimethyl pyrimidin-4-yl)pyrazole-4-carboxaldehyde (2g) were found to be equipotent to streptomycin and chloramphenicol against gram-negative bacteria, E. coli having minimum inhibitory concentration (MIC) value = 4 βg/mL. Compounds 4b and 4d also displayed good activity against E. coli with MIC = 8 βg/mL.