反应详情

温度

5 °C

To a suspension of 6-chloro-8-methyl-2H-3,1-benzoxazine-2,4(1H)-dione (211.6 g, 1000 mmol) in acetonitrile (700 mL) was added acetic acid (7.3 g, 122 mmol). Then 40% aqueous methylamine (104 mL) was added dropwise over 30 minutes at 25-30° C. Stirring was continued for 2 h, and then water (700 mL) was added slowly. The resulting suspension was cooled to 5° C., and stirred for 30 minutes at this temperature. The suspension was then filtered, and the solids were washed with water (3×200 mL) and dried under nitrogen to afford the title compound as off-white needles, 172.8 g (87.0% yield), m.p. 141-143° C.

1. stirringstirred for 30 minutes at this temperature
2. filtrationThe suspension was then filtered
3. washthe solids were washed with water (3×200 mL)
4. customdried under nitrogen