Copper‐Catalysed Tandem Synthesis of Substituted Quinazolines from Phenacyl Azides and O‐Carbonyl Anilines

An efficient protocol for the synthesis of substituted quinazolines from 2‐aminoacetophenones/benzophenones and phenacyl azides using copper catalysed base mediated system is developed. This method utilizes phenacyl azides for generation of imine precursors for transimination with o‐carbonyl anilines followed by condensation to yield quinazolines. This mild catalytic system is efficient in construction of two C−N bonds in a single operation. The reaction proceeded well to give a series of 22 examples of quinazolines with good to excellent yields and wide range of functional group tolerance. A copper‐catalysed base mediated approach was developed for the synthesis of substituted quinazolines. The present work involves various phenacyl azides as starting materials, which liberates –N2 under basic conditions to provide a reactive intermediate that reacts with o‐carbonyl ketones to give quinazolines in good to excellent yields. This operationally simple method provides quinazolines in short reaction time, showed wide range of functional group tolerance and broad substrate scope.