Facile and efficient synthesis of quinazoline-2,4(1H,3H)-diones through sequential hydrogenation condensation

ABSTRACT

The heterocyclizations from various methyl (2-nitrobenzoyl)carbamates to substituted quinazoline-2,4(1H,3H)-diones under hydrogenation conditions were investigated in this study. In the presence of p-toluenesulfonic acid monohydrate in methanol, various quinazoline-2,4(1H, 3H)-diones were obtained in good to excellent yields within 12 h. The reaction was proposed to proceed through the cascade reactions of nitro reduction and condensation.

GRAPHICAL ABSTRACT

KEYWORDS:

• Cascade reaction
• heterocyclization
• hydrogenation condensation
• quinazoline-2,4(1H,3H)-dione

Additional information

Funding

This work was supported by the National Natural Science Foundation of China under Grant 81703362; CAMS Innovation Fund for Medical Sciences under Grant CAMS-2016-I2M-1-010; and Fundamental Scientific Research Fund of Chinese Academy of Medical Sciences under Grant 2016ZX350030.