Synthesis of N3-substituted-quinazoline-2,4(1H,3H)-diones via CuI-catalyzed coupling of 2-iodobenzamides with potassium cyanate

Abstract

Herein, we disclosed the synthesis of N3-substituted-quinazoline-2,4(1H,3H)-diones via the consecutive copper-catalyzed coupling/annulation of 2-iodobenzamides and KOCN. This transformation is characterized by the in situ-generation of arylisocyante through C(sp²)-N(sp²) bond formation, which enriches the library of preparation quinazolindiones. Moreover, it is worth noting that replacing the iodo group with bromo also produced a comparable yield of the corresponding quinazolinedione derived under the present conditions.