An Oxidant-Free and Mild Strategy for Quinazolin-4(3<i>H</i>)-One Synthesis via CuAAC/Ring Cleavage Reaction

Abstract

An oxidant-free and highly efficient synthesis of phenolic quinazolin-4(3H)-ones was achieved by simply stirring a mixture of 2-aminobenzamides, sulfonyl azides, and terminal alkynes. The intermediate N-sulfonylketenimine underwent two nucleophilic additions and the sulfonyl group eliminated through the power of aromatization. The natural product 2-(4-hydroxybenzyl)quinazolin-4(3H)-one can be synthesized on a large scale under mild conditions with this method.

Keywords

• CuAAC/ring cleavage reaction
• nucleophilic addition
• natural product
• quinazolin-4(<i>3H</i>)-ones
• ketenimine