Synthesis, characterization and in vitro antifungal evaluation of novel benzimidazo[1,2-c]quinazolines

Abstract

The synthesis of a series of new benzimidazo[1,2-c]quinazolines starting from 2-nitrobenzaldehyde and o-phenylendiamine is described. The structure elucidation of the products is based on detailed NMR analysis of experiments such as H-1-COSY, NOESY, DEPT, HSQC and HMBC. These compounds showed antifungal properties only against dermatophytes. Among them, those with electron-donor substituents on the 6-phenyl ring inhibited mainly T. rubrum and E. floccosum with MICs between 25-250 mu g/mL and M. canis, M gypseum and T. mentagrophytes with MICs between 50-250 mu g/mL. Structures with electron-withdrawing substituents on the phenyl ring did not show any activities up to 250 mu g/ml. Methyl substituents on the benzimidazole ring seem negatively affect the antifungal behaviour of this series.