Palladium-catalyzed four-component carbonylative synthesis of 2,3-disubstituted quinazolin-4(3H)-ones: Convenient methaqualone preparation

Abstract

A palladium-catalyzed four-component carbonylative cyclization reaction for the synthesis of 2,3-disubstituted quinazolin-4(3H)-ones has been developed. A range of different 2,3-disubstituted quinazolin-4(3H)-one derivatives were prepared in moderate to good yields employing simple and readily accessible 2-iodoanilines, nitro compounds and acid anhydrides as the synthetic precursors. Mo(CO)6 acted both as a solid CO source and a reductant. Notably, methaqualone as a sedative and hypnotic medication can be prepared easily in 68% yield (4b) under our conditions as well.