Synthesis of tetrahydrobenzo[b]pyran derivatives using a novel zirconia supported sodium hexamolybdochromate(III) catalyst

Novel zirconia supported sodium hexamolybdochromate(III) has been synthesized and used as an efficient catalyst for the synthesis of 4H-benzo[b]pyran derivatives by one-pot three-component condensation of aldehydes, C-H activated compound and dimedone in ethanol at reflux condition. The catalyst was characterized by FT-IR, XRD, EDS, SEM and TGA. EDS analysis explored the pure form of the catalyst, while the XRD pattern indicates that, sodium hexamolybdochromate(III) underegoes in amorphous state. The catalyst is heterogeneous and can be recovered by a simple filtration method. It is reused four times without any major activity loss.