One-Pot Three-Component Reaction for the Synthesis of 3,4-Dihydroquinazolines and Quinazolin-4(3H)-ones

Abstract

A highly efficient and straightforward one-pot synthesis of diversely substituted 3,4-dihydroquinazolines and quinazolin-4(3H)-ones has been achieved through a domino three-component assembly reaction of arenediazonium salts, nitriles, and bifunctional aniline derivatives. This new protocol involves three C−N bond formations through the initial formation of N-arylnitrilium intermediates from arenediazonium salts and nitriles, followed by the sequential nucleophilic addition and cyclization reactions with bifunctional anilines, leading to such Nheterocyclic compounds of biological and pharmacological importance. This method offers a simple, expedient, and robust approach with the use of amenable and easily accessible reactants/ reagents under metal-free mild conditions, good functional group tolerance, and high efficiency. The synthetic applications were also demonstrated by derivatization of the products obtained from these processes and syntheses of a diverse range of valuable polycyclic N-heterocycles.