Green Approach for the Synthesis of a New Class of Diamidomethane‐linked Benzazolyl Pyrazoles and Evaluation as Antifungals

Abstract

A new class of diamidomethane‐linked benzoxazolyl pyrazoles, benzothiazolyl pyrazoles, and benzimidazolyl pyrazoles were synthesized from the synthetic intermediates N‐benzazolylcarbamoylmethylcinnamides adopting environmentally benign methods. In fact, nitrile imine was generated from araldehyde phenylhydrazone in the presence of iodosobenzene and cetyltrimethylammonium bromide followed by oxidation with iodine in dimethylsulfoxide. The structures of compounds were characterized by IR, 1H NMR, 13C NMR, and mass spectra. The title compounds were also evaluated for their antifungal activity. Amongst all the tested compounds benzimidazolyl pyrazolyl carboxamides (13a and 13b) were found to be potential antifungal agents.

Synthesis of Antimicrobial Benzimidazole–Pyrazole Compounds and Their Biological Activities

“…Sowdari et al, synthesized a new class of diamidomethane-linked benzazolyl–pyrazoles 64a – 64c by a green approach, using the synthesis strategy indicated in Scheme 16 [ 70 ]. Compounds 64a and 64c were found to be potential antifungal agents against Aspergillus niger (MIC = 50 and 25 μg mL −1 , respectively) and Penicillium chrysogenum (MIC = 12.5 and 12.5 μg mL −1 , respectively) compared to the standard drug, Ketoconazole.…”