Microwave-Assisted, Green Synthesis of 4(3H)-Quinazolinones under CO Pressure in γ-Valerolactone and Reusable Pd/β-Cyclodextrin Cross-Linked Catalyst

The development of alternative, green solvents is an important and ongoing challenge. Our latest contribution to the field is the use of γ-valerolactone in aminocarbonylative coupling reactions for the clean synthesis of several 4(3H)-quinazolinones under microwave irradiation. The palladium-catalyzed, four-component carbonylative coupling reactions of o-iodoanilines, trimethyl orthoformate, and a variety of amines have been carried out under CO pressure (2.5 bar). This protocol was found to be highly efficient and selective for 4(3H)-quinazolinones, which were isolated in good yields in the presence of two different, recyclable Pd catalysts which were prepared under ultrasound irradiation; a novel lead-free Pd/boehmite catalyst and a β-cyclodextrin-cross-linked Pd catalyst.