Selective synthesis of 2-substituted 2,3-dihydroquinazolin-4(1H)-ones and quinazolin-4(3H)-ones catalyzed by Schiff base dioxomolybdenum(VI) complex

Schiff base dioxomolybdenum(VI) complex is found to be a novel and efficient catalyst for the selective synthesis of 2-substituted 2,3-dihydroquinazolin-4(1H)-ones via condensation of 2-aminobenzamide with aldehydes or ketones. Also, this catalyst is also found to be efficient for the construction of quinazolin-4(3H)-ones while in the presence of hydrogen peroxide as oxidant. At higher temperature the aldehydes undergo an oxidative cyclization reaction affording the quinazolin-4(3H)-ones. Herein we report a novel protocol with practical simplicity, broad substrate scope, good selectivity, moderate to excellent yields, and low catalyst loading (0.5% mol).

Automated summary

In this study, a novel and practical method was reported for the selective synthesis of 2-substituted 2,3-dihydroquinazolin-4(1H)-ones via condensation of 2-aminobenzamide with aldehydes or ketones, using a Schiff base dioxomolybdenum(VI) complex as an efficient catalyst with low loading (0.5% mol). Additionally, this catalyst was also found to be efficient for the construction of quinazolin-4(3H)-ones in the presence of hydrogen peroxide, through an oxidative cyclization reaction at higher temperature.