An environmentally friendly, chemoselective, and efficient protocol for the preparation of coumarin derivatives by Pechman condensation reaction using new and reusable heterogeneous Lewis acid catalyst polystyrene-supported GaCl3

An environmentally benign Pechman protocol for the one-pot synthesis of 4-substituted coumarins through the condensation reactions of phenol substrates with β-ketoesters using polystyrene-supported GaCl3 (PS–GaCl3) as a highly active and reusable solid Lewis acid catalyst under mild and heterogeneous conditions in good to excellent yields is described. This new protocol is easy, simple, cost-effective, chemoselective, and in addition has the advantages of easy availability, stability, reusability and eco-friendly character of the catalyst, high to excellent yields, simple experimental and work-up procedure.