Poly(4-vinylpyridinium)hydrogensulfate as an efficient and convenient catalyst for a three-component synthesis of 7-methyl-10-aryl-10H-5,8-dioxa-benzo[b]fluoren-9,11-diones

A simple and facile synthesis of 7-methyl-10-aryl-10 H -5,8-dioxa-benzo[ b ]fluoren-9,11-dione derivatives was accomplished via a one-pot condensation of aldehydes, 4-hydroxy-6-methylpyran-2-one, and 2 H -indene-1,3-dione at 80 °C under solvent-free conditions in the presence of poly(4-vinyl)pyridinium hydrogen sulfate as a solid acid catalyst. This method has several advantages including high yield of products, shorter reaction times, simple work-up, and cleaner reaction profile.