Synthesis, antibacterial and antimycobacterial activities of some new 4-aryl/heteroaryl-2,6-dimethyl-3,5-bis-N-(aryl)-carbamoyl-1,4-dihydropyridines

A novel class of 4-aryl/heteroaryl-2,6-dimethyl-3,5-bis-N-(phenyl/substituted phenyl)-carbamoyl-1,4-dihydropyridines has been synthesized by simple, economical and eco-friendly, modified Hantzsch condensation reaction making use of N-arylacetoacetamides, aryl or heteroaryl aldehydes and ammonium acetate. The newly synthesized compounds were characterized by their spectral (IR, 1H NMR, Mass), elemental analyses data and evaluated for in vitro antitubercular activity against Mycobacterium tuberculosis H37Rv ATCC 27294 and antibacterial activity against different Gram +ve and Gram −ve bacteria. The preliminary screening results revealed that some of the compounds possess promising antimicrobial activity. Amongst the new series of compounds, 6m containing pyrrolyl and 4-methylphenyl groups and 6r possessing 2-pyridyl and 2-methylphenyl groups were found to exhibit a significant antitubercular activity (MIC = 12.5–25 μg/mL) in comparison with the first line drug pyrazinamide.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We report the rapid, facile and high yielding syntheses of new 1,4-dihydropyridines. ► Few compounds exhibited potent antibacterial and antitubercular activities. ► Anti-TB activity against various strains of T.B was comparable with pyrazinamide.