Synthesis of novel imidazo[1,2-a] pyridines and evaluation of their antifungal activities

Abstract

New 2-(imidazo[1,2-a] pyridin-2-ylcarbonyl)-N-substituted hydrazinecarbothioamides (4a-j), N'-(3-substituted-4-oxo-1,3-thiazolidin-2-ylidene) imidazo[1,2-a] pyridine-2-carbohydrazides (5a-f), and N-(nonsubstituted/4-substituted phenyl)-5-(imidazo[1,2-a] pyridine-2-yl)-1,3,4-oxadiazole-2-amines (6a-d) were synthesized from imidazo[1,2-a] pyridine-2-carbohydrazide (3) and evaluated for antifungal activity against Microsporum gypseum NCPF 580, M. canis, Trichophytontonsurans NCPF 245, T. rubrum, Candida albicans ATCC 10231, and C. parapsilosis ATCC 22019 using amphotericin B as the standard. The chemical structures of the compounds were confirmed by elemental analysis, IR, H-1 NMR, C-13 NMR, HMBC (C-13, H-1), and mass spectra. Most of the tested compounds showed moderate antifungal activity. Hydrazinecarbothioamide derivatives 4h and 4f exhibited the highest activity against M. canis (MIC: 2 mu g mL(-1) and 4 mu g mL(-1), respectively).