Photocatalytic synthesis of 2,4-substituted quinazolines via a one-pot, three-component reaction under catalyst-free conditions

A novel, catalyst-free photoinduced synthesis of 2,4-substituted quinazoline using 2-amino-aryl ketone, an aldehyde, and ammonium acetate was developed. A series of 2,4-substituted quinazoline compounds were obtained via irradiating the reactants with a light-emitting diode light (18 W) at room temperature. The broad substrate range and excellent gram-scale experimental results demonstrate the versatility of the reaction. To the best of our knowledge, the synthesis of 2,4-substituted quinazoline using ammonium acetate as the nitrogen source under photocatalysis has not been reported thus far. This method utilizes visible light oxidation to eliminate the use of oxidants in the reaction and is complementary to previous methods.