反应详情

温度

80 °C

To a 0° C. mixture of 2-amino-4-bromo-5-fluorophenol (38.0 g, crude from previous step) and K2CO3 (76.0 g, 553 mmol) in DMF (100 mL) was added 2-chloroacetyl chloride (23.0 g, 15.3 mL, 203 mmol) drop-wise. The reaction mixture was heated at 80° C. overnight then cooled to ambient temperature and poured into water (300 mL). The precipitate was collected by filtration, washed with water and dried to give 6-bromo-7-fluoro-4H-benzo[1,4]oxazin-3-one (41.0 g, 90%). 1H NMR (DMSO-d6, 400 MHz): δ 7.13 (m, 2H), 4.62 (s, 2H). The amide proton was not observed.

1. temperaturethen cooled to ambient temperature
2. filtrationThe precipitate was collected by filtration
3. washwashed with water
4. customdried