Synthesis of Quinazolin-4(3H)-ones via Pd(II)-Catalyzed Intramolecular C(sp2)-H Carboxamidation of N-arylamidines

An efficient synthesis of quinazolin-4(3H)-ones from N-arylamidines, through palladium-catalyzed intramolecular C(sp(2))-H carboxamidation, has been developed. The reaction, carried out in the presence of 1.0 equiv of CuO as oxidant under atmospheric pressure of CO, provides diversified 2-aryl(alkyl)-quinazolin-4(3H)-ones in reasonable to good yields from N-arylamidines, which are readily derived from anilines and nitriles. Compared with existing approaches to quinazolin-4(3H)-ones, the current strategy features atom-economy and step-efficiency.