Novel Pumice Supported Perchloric Acid Promoted Protocol for the Synthesis of Tetrahydrobenzo[b]pyran via Multi-component Approach

A novel heterogeneous pumice supported perchloric acid catalyzed synthesis of tetrahydrobenzo[b]pyran has developed via multi-component condensation of aromatic aldehydes, dimedone and malononitrile. The catalyst was characterized by IR, XRD, EDS, SEM, and TGA techniques which confirmed the formation novel pumice supported perchloric acid. The present protocol proved to have numerous advantages like one-pot reaction, good yield, short reaction time, inexpensive catalyst, recyclability and reusability of the catalyst, simple experimental and work up procedure, and purification of targeted molecules without column chromatography.