Tandem synthesis of quinazolinone scaffolds from 2-aminobenzonitriles using aliphatic alcohol-water system

Ru(ii) complex catalyzed tandem synthesis of quinazolinone derivatives is reported here. In this sustainable protocol, 2-aminobenzonitriles were directly transformed to quinazolinones using alcohol-water system. A variety of quinazolinones was successfully synthesized in good to excellent yields by utilizing challenging methanol and aliphatic alcohols. The practical applicability of the protocol was extended by preparative scale synthesis of various heterocycles as well as natural products. To understand the mechanism of this protocol, several control experiments and DFT studies were carried out. Based on the DFT calculations, a metal-ligand cooperative mechanism was proposed for this system.