Novel dibenzo-18-crown-6 ether functionalized bis-benzimidazole derivatives: synthesis and antifungal evaluation

Abstract

A series of novel 18-crown-6 ether functionalized bis-benzimidazole derivatives (3a–g) have been synthesized by reacting various substituted ortho-phenylene diamines and pyridine diamines with 4,4′-diformyl dibenzo-18-crown-6 ether (1). The required starting material 4,4′-diformyl dibenzo-18-crown-6 ether (1) was prepared by Duff formylation method. All synthesized novel molecules have been identified on the basis of infrared (IR), 1H nuclear magnetic resonance (NMR), 13C NMR, mass spectroscopy (MS), and elemental analyses. The title compounds (3a–g) were tested for antifungal activity against Aspergillus niger, Trichothecium sp., Rhizopus sp., and Sclerotium rolfsii fungi species using agar well diffusion method, showing mild to good results.