CuBr-catalysed one-pot multicomponent synthesis of 3-substituted 2-thioxo-2,3-dihydroquinazolin-4(1H)-one derivatives

A novel methodology is presented for the synthesis of 3-substituted 2-thioxo-2,3-dihydroquinazolin-4(1H)-one derivatives based on an efficient tandem multicomponent reaction using copper bromide as catalyst. This methodology is based on the multicomponent one-pot reaction of methyl 2-bromobenzoate, phenylisothiocyanate derivatives and sodium azide in the presence of copper bromide and l-proline under basic conditions. To show the generality of the method, various phenylisothiocyanates bearing electron-donating or electron-withdrawing functionalities were used and the desired products were obtained in high isolated yields.