反应详情

Boric acid (20.45 g, 330.7 mmol), and hydrogen peroxide (35%, 36.8 mL) in tetrahydrofuran (150 ml) was treated with concentrated sulfuric acid (15 ml) and the mixture was stirred at rt for 30 min. 1-(5-Fluoro-2-hydroxy-3-nitrophenyl)ethanone (15 g, 75.4 mmol) in tetrahydrofuran (45 ml) was added and reaction heated for 48 h at 75° C. The reaction mixture was cooled to rt, diluted with water and extracted with DCM (3×500 ml). The combined organic phases were dried on magnesium sulphate, evaporated and the residue was subjected to column chromatography on silica gel using a 20%-80% EtOAc: 40-60 petroleum ether gradient to provide the desired compound (6.55 g, 50%), a 5:1 mixture of desired product and 1-(5-fluoro-2-hydroxy-3-nitrophenyl)ethanone (4 g) and recovered 1-(5-fluoro-2-hydroxy-3-nitrophenyl)ethanone (1.5 g).

1. customreaction
2. temperatureheated for 48 h at 75° C
3. temperatureThe reaction mixture was cooled to rt
4. extractionextracted with DCM (3×500 ml)
5. customThe combined organic phases were dried on magnesium sulphate
6. customevaporated