反应详情

温度

170 °C

Urea (Sigma; 3.78 g, 63.0 mmol) and 2-amino-3-bromo-benzoic acid (Aldrich; 4.00 g, 18.52 mmol) were combined and heated, open to air, in a 170° C. oil bath. After 3 h, additional urea (Sigma; 3.78 g, 63.0 mmol) was added and stirring continued. After 5 h, the reaction was judged complete and cooled, treated with water, filtered, and the solid dried overnight in vacuo to give 4.7 g. The material was treated with water and stirred rapidly for 3 h to give a fine suspension. The solid was collected by filtration and dried in vacuo overnight, to give 8-bromoquinazoline-2,4(1H,3H)-dione (4.30 g, 17.84 mmol, 96% yield) as a light yellow solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 11.50 (1H, br. s.), 10.25 (1H, br. s.), 7.93 (2H, dq, J=7.8, 1.4 Hz), 7.13 (1H, t, J=7.8 Hz). m/z (ESI, +ve ion) 240.9/242.9 (M+H)+.

1. waitAfter 5 h
2. temperaturecooled
3. filtrationfiltered
4. customthe solid dried overnight in vacuo
5. customto give 4.7 g
6. stirringstirred rapidly for 3 h
7. customto give a fine suspension
8. filtrationThe solid was collected by filtration
9. customdried in vacuo overnight