Novel Annulation of Cyanuric Chloride with 2‐Aminobenzamides: A New Approach to 2‐Amino‐3‐substituted Quinazolin‐4(3H)‐ones

A simple and efficient method for preparation of 2‐amino‐ 3‐substituted quinazolin‐4(3H)‐ones by reaction of cyanuric chloride with 2‐amino N‐substituted benzamides in acetonitrile‐water (2 : 1) using sodium bicarbonate as a mild base is described. Using this metal‐free method, a variety of 2‐amino‐3‐substituted quinazolin‐4(3H)‐ones were obtained in good to excellent yields. Here, both organic and inorganic bases were found to promote this reaction and the best results were observed with sodium bicarbonate. This study is the first observation of cyanuric chloride to act as a source for creation of amine functionality in 2‐amino‐3‐substituted quinazolin‐4(3H)‐ones. A new approach has been developed for synthesis of 2‐amino‐3‐substituted quinazolin‐4(3H)‐ones by annulation reaction of cyanuric chloride with 2‐amino benzamides in high yields under metal‐free conditions. This reaction is the first observation of cyanuric chloride as an amine source, though it was known for a variety of application in organic synthesis. Detailed substrate scope, mechanistic studies and synthetic applications have been explored.