Silica sulfuric acid: An efficient reusable heterogeneous catalyst for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones in water and under solvent-free conditions

Silica sulfuric acid as a heterogeneous reagent catalysed eco-friendly and efficient synthesis of 2,3-dihydroquinazolinones by the reaction of isatoic anhydride, a primary amine or ammonium acetate and an aromatic aldehyde in water or under solvent-free conditions. The solid acidic catalyst could be recycled and reused.