Silica supported zinc (II) chloride (SiO 2 -ZnCl 2 ) as an efficient and non-toxic heterogeneous catalyst have been used for the simple and facile synthesis of 2,3-dihydroquinazolin-4(1H)-ones through the direct cyclo-condensation of anthranilamide and aldehydes or one-pot three-component cyclo-condensation of isatoic anhydride, ammonium acetate (or amines) and aldehydes under solvent-free conditions.