Synthesis and pharmacological evaluation of novel 2H/6H-thiazolo-[3′,2′:2,3][1,2,4]triazolo[1,5-a]pyridine-9-carbonitrile derivatives

In the present study a new series of 3-hydroxy-7-isocyano-6-oxo-8-phenyl-2-(substitutedphenyl(piperidin-1-yl)methyl)-6H-thiazolo-[3′,2′:2,3][1,2,4]triazolo[1,5-a]-pyridine-9-carbonitrile (5a–j) and (Z)-2-(4-substitutedbenzylidene)-7-isocyano-3,6-dioxo-8-phenyl-3,6-dihydro-2H-thiazolo-[3′,2′:2,3][1,2,4]triazolo[1,5-a]pyridine-9-carbo-nitrile derivatives (4a–j) were synthesized. The newly synthesized compounds were characterized by IR, 1H NMR, LC–MS mass, and C, H, N analyses. All newly synthesized compounds were screened for their antibacterial (Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, Streptococcus pyogenes, and Klebsiella pneumoniae) and antifungal (Aspergillus flavus, Aspergillus fumigatus, Candida albicans, Penicillium marneffei and Trichophyton mentagrophytes) activity. The results revealed that all synthesized compounds have a significant biological activity against the tested microorganisms. Compounds 4a, 4f, 4i, 4j, 5a, 5i, and 5j exhibited good antimicrobial activity.