A regioselective three-component reaction for synthesis of novel 1′H-spiro[isoindoline-1,2′-quinazoline]-3,4′(3′H)-dione derivatives

A ring opening and regioselective three-component reaction of isatoic anhydride, isatins, and aromatic or aliphatic primary amines in the presence of catalytic amount of KAl(SO4)2·12H2O (alum) to yield a novel series of 1′H-spiro[isoindoline-1,2′-quinazoline]-3,4′(3′H)-dione is described.