反应详情

To a mixture of 8-methoxy-4,4-dimethyl-1,4-dihydro-2H-3,1-benzoxazin-2-one (2.1 g, 10.1 mmol), sodium acetate (1.5 g, 18 mmol) in acetic acid (30 mL) was added bromine (0.62 mL, 12 mmol) at ambient temperature. After 30 minutes, the solution was treated with a concentrated ammonium hydroxide solution (50 mL). The precipitate was collected on a filter and washed with water (3×20 mL) to yield 6-bromo-8-methoxy-4,4-dimethyl-1,4-dihydro-2H-3,1-benzoxazin-2-one (2.7 g, 93%) as off-white solid: MS (ESI) m/z 286, 288 [M +H]+.

1. customThe precipitate was collected on
2. filtrationa filter
3. washwashed with water (3×20 mL)