Diazonium Salts Induced Divergent Synthesis of α,β-Unsaturated-Azo-Substituted-Quinazolin-2(1H)-ones and Quinolinones via Sequential Cyclization and Skeletal Rearrangement

Abstract

We have successfully developed a novel synthetic route for the synthesis of α,β-unsaturated-azo-substituted-quinazolin-2(1H)-one via a reaction between 1,3-diphenylurea analogues and diazonium salts, facilitated by a diazonium salt-induced intramolecular cyclization process. Notably, this reaction exhibits remarkable tolerance toward a wide range of substituents, resulting in the formation of diverse products under mild reaction conditions. Additionally, we discovered that rearrangement occurs under alkaline conditions, leading to the formation of α,β-unsaturated-azo-substituted-quinolinone derivatives.