反应详情

温度

80 °C

To a solution of 2-amino-4-bromophenol (25 g, 133.0 mmol), NaHCO3 (22.4 g, 266.0 mmol) in 4-methylpentan-2-one (50 mL) and water (50 mL) at 0° C. was added 2-chloroacetyl chloride (10.0 mL, 200.0 mmol) dropwise. The reaction mixture was stirred at 80° C. for 24 h then cooled to ambient temperature and filtered. The filtrate was washed with water (3×10 mL) and dried over anhydrous Na2SO4. After filtration, the organic phase was evaporated to give 6-bromo-4H-benzo[1,4]oxazin-3-one as a white solid (27 g, 89%). 1H NMR (CDCl3, 400 MHz): δ 8.49 (brs, 1H), 7.08 (dd, J=8.4 Hz, J=2.0 Hz, 1H), 6.93 (d, J=2.0 Hz, 1H), 6.87 (d, J=8.4 Hz, 1H), 4.61 (s, 2H).

1. temperaturethen cooled to ambient temperature
2. filtrationfiltered
3. washThe filtrate was washed with water (3×10 mL)
4. dry with materialdried over anhydrous Na2SO4
5. filtrationAfter filtration
6. customthe organic phase was evaporated