反应详情

To a combined solution of acetonitrile (360 mL) and water (90 mL) was added 6-bromo-1H-benzo[d][1,3]oxazine-2,4-dione (24.2 g, 0.1 mol), 1,2-dimethyl-isothiourea hydriodic (23.2 g, 0.1 mol) followed by anhydrous sodium carbonate (11.7 g, 0.11 mol) and the mixture was heated to reflux for 3 hours. After cooling down, the precipitate was collected by filtration, washed with water to afford 6-bromo-2-methylamino-1H-quinazolin-4-one (16.5 g, 65 mmol, 65%) as a light yellow powder. 1H NMR (DMSO-d6): δ 11.20 (b, 1H), 7.91-7.90 (d, 1H), 7.64-7.63 (d, 1H), 7.20-7.18 (d, 1H), 6.30 (b, 1H), 2.82-2.81 (d, 3H).

1. temperaturethe mixture was heated
2. temperatureto reflux for 3 hours
3. temperatureAfter cooling down
4. filtrationthe precipitate was collected by filtration
5. washwashed with water