反应详情

To 500 mg of 5% Pd/C in a Parr bottle was added 100 ml of EtOH followed by 5.0 g (21.8 mmol) of methyl 5-fluoro-2-nitrophenoxyacetate. The flask was placed in a Parr Apparatus, evacuated and then charged with hydrogen. The suspension was then shaken for 2 hours. After evacuating the flask and recharging with nitrogen, the solids were removed by vacuum filtration through Celite®. Since some product does precipitate, the filter cake is repeatedly rinsed with EtOAc (200 ml). The filtrate is refluxed for 4 hours and then evaporated to dryness in vacuo to give the desired material, 7-fluoro-2H-1,4-benzoxazin-3(4H)-one, as a white solid (m.p. 201°-202° C.) in quantitative yield.

1. customevacuated
2. additioncharged with hydrogen
3. customAfter evacuating the flask
4. customthe solids were removed by vacuum filtration through Celite®
5. washthe filter cake is repeatedly rinsed with EtOAc (200 ml)
6. temperatureThe filtrate is refluxed for 4 hours
7. customevaporated to dryness in vacuo