反应详情

温度

-5 °C

To a mixture of 1-(2-fluoro-4-hydroxy-phenyl)-ethanone (5 g, 32.5 mmol) in concentrated sulfuric acid (50 mL) at −5° C. was added KNO3 (3.29 g, 32.6 mmol) in portions and the mixture was stirred for 3 h at −5° C. The mixture was poured into ice water (120 mL) and the aqueous solution was extracted with EtOAc (3×50 mL). The combined organic phase was washed with brine (100 mL), dried over anhydrous Na2SO4 and filtered. The filtrate was evaporated in vacuo and the residue was purified by column chromatography on silica gel (eluting with 2-10% EtOAc in petroleum ether) to give 1-(2-fluoro-4-hydroxy-5-nitro-phenyl)-ethanone as a yellow solid (4.59 g, 71%). 1H-NMR (CDCl3, 400 MHz): δ 10.95 (s 1H), 8.79 (d, J=7.2 Hz, 1H), 6.92 (d, J=11.2 Hz, 1H), 2.63 (d, J=5.2 Hz, 3H).

1. extractionthe aqueous solution was extracted with EtOAc (3×50 mL)
2. washThe combined organic phase was washed with brine (100 mL)
3. dry with materialdried over anhydrous Na2SO4
4. filtrationfiltered
5. customThe filtrate was evaporated in vacuo
6. customthe residue was purified by column chromatography on silica gel (eluting with 2-10% EtOAc in petroleum ether)