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

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-substitu- ted 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, Trichophyton tonsurans 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, 1H NMR, 13C NMR, HMBC ( 13C, 1H), 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 µg mL ^−1 and 4 µg mL ^−1 , respectively).