Green Synthetic Approach and Antimicrobial Evaluation for Some Novel Pyridyl Benzoate Derivatives

Abstract

Two series of substituted pyridyl 4-chlorobenzoates have been synthesized by microwave-assisted condensation of the corresponding 2-oxo-1,2-dihydropyridine-3-carbonitriles with 4-chlorobenzoyl chloride under solvent-free conditions. Alternatively, some compounds have also been prepared by conventional heating in methylene chloride in the presence of triethylamine. The structure of the synthesized compounds has been confirmed by spectral data (FTIR, 1D and 2D NMR). The new pyridyl benzoates were evaluated for antibacterial activity against gram-negative and gram-positive bacteria. The activity of 3-cyano-5-[(4-hydroxyphenyl)diazenyl]-4-methyl-6-phenylpyridin-2-yl 4-chlorobenzoate against gram-positive bacteria (Bacillus subtilis and Staphylococcus aureus) was comparable to that of amikacin used as standard antibiotic.