反应详情

温度

80 °C

Iron powder (36.42 g) was suspended in 5% aqueous acetic acid (69 ml) and heated to 80° C. To the suspension, a solution of ethyl 5-fluoro-2-nitrophenoxyacetate (15.86 g) in acetic acid (65 ml) and ethyl acetate (65 ml) was dropwise added, and the resultant mixture was heated at 60° to 80° C. under reflux for 3 hours. After removal of residue by filtration, the filtrate was extracted with ethyl acetate. The extract was washed with water and sodium bicarbonate solution, dried and concentrated to give 7-fluoro-2H-1,4-benzoxazin-3(4H)-one (6.82 g). m.p., 186.720 C. 1H-NMR (CDCl3 +DMSO-D6) δ ppm: 4.2 (1H, broad), 4.51 (2H, s), 6.5-7.0 (3H, m).

1. temperatureunder reflux for 3 hours
2. customAfter removal of residue
3. filtrationby filtration
4. extractionthe filtrate was extracted with ethyl acetate
5. washThe extract was washed with water and sodium bicarbonate solution
6. customdried
7. concentrationconcentrated