Onion (Allium cepa L.) Extract: A Green and Eco-friendly Catalyst for MW-Assisted Solvent-Free Synthesis of Pyrroles via Paal–Knorr Reaction

Abstract

An environmentally friendly and highly efficient method for onion extract-catalyzed microwave-assisted solvent- free synthesis of pyrroles via Paal–Knorr reaction with hexane-2,5-dione has been developed. This method is applicable to a wide range of aromatic, aliphatic, and heterocyclic primary amines, and it affords various pyrrole derivatives in good to excellent yields (up to 98%) at 80°C. The use of onion extract as catalyst makes the process environmentally benign.