Ionic Liquid‐Mediated Facile Synthesis of Novel Spiroheterobicyclic Rings as Potential Antifungal and Antibacterial Drugs

Abstract

A pseudo four‐component reaction of urea or thiourea, diverse aryl aldehydes, and 3‐methyl‐1‐phenyl‐2‐pyrazolin‐5‐one in ionic liquids yields novel azaspiro[4.5]decene derivatives. However, the corresponding reaction in volatile organic solvents gives Knoevenagel adduct as a major product with little amount of the title compound. Interestingly, the expected pyrimidine derivative was not formed in any case. The advantageous features of this methodology are the environmentally benign character, operational simplicity, high yield processing, and easy handling without any catalyst. All the compounds were subjected to in vitro antimicrobial screening against a panel of pathogenic strains of bacteria and fungi. Some of the compounds were found to be equipotent or more potent than the commercial antibiotics.