One-pot synthesis of mono- and disubstituted (3H)-quinazolin-4-ones in dry media under microwave irradiation

AlCl3/ZnCl2 mixture supported on silica gel is an efficient medium for one-pot synthesis of (3H)-quinazolin-4-ones in the absence of solvent under microwave irradiation or classical heating. The reaction of orthoesters with 2-aminobenzamides ends up with the formation of monosubstituted (3H)-quinazolin-4-ones. One-pot synthesis of disubstituted (3H)-quinazolin-4-ones is also achieved by the reaction of isatoic anhydride with primary amines and orthoesters.