Novel 1,2,3-triazole-1,4-dihydropyridine-3,5-dicarbonitrile derivatives: synthesis and antibacterial evaluation

The purpose of this study was the synthesis of a novel series of 1,2,3-triazole-1,4-dihydropyridine-3,5-dicarbonitrile derivatives (3a-3o) via Cu(I) catalyzed reaction between a terminal alkyne and substituted alkyl or aryl azides.  The synthesized triazoles were characterized by 1 H NMR, 13 C NMR, and single crystal X-Ray. They were screened in vitro for antibacterial activity against a set of 10 bacterial cultures by the broth microdilution method. The significant antibacterial activity with MIC: 50 μg mL - 1 was displayed by compounds 3j and 3h against Pseudomonas aeruginosa and compounds 3c and 3g against Salmonella paratyphi as well as compound 3f against Enterobacter aerogenes , Klebsiella pneumoniae , Proteus vulgaris , and Shigella flexneri . Compound 3e was the only compound that was found to inhibit Escherichia coli with MIC: 200 μg mL -1 .