Heteropolyacid-clay nano-composite as a novel heterogeneous catalyst for the synthesis of 2,3-dihydroquinazolinones

The present research work is intended to synthesize a series of substituted 2,3-dihydro-2-phenylquinazolin-4(1H)-ones using clay-supported heteropolyacid as a novel heterogeneous, reusable and inexpensive catalyst. This catalyst afforded excellent yields in very short reaction times that shows high selectivity without affecting other functional groups, such as carbon–carbon double bond and heterocyclic moieties. The catalyst could be recycled at least six times and reused. The synthesis involves cyclo-condensation of anthranilamide with an aldehyde at room temperature in the presence of small amount of the catalyst. No column purification is required and products can be purified by simple crystallization.