反应详情

温度

70 °C

1-(5-Acetoxy-6,7-dimethyl-benzofuran-2-yl)-ethanone (83 mg) (prepared from 1-(5-hydroxy-6,7-dimethyl-benzofuran-2-yl)-ethanone from Example 14 with acetanhydride and pyridine), was dissolved in chloroform (10 mL). Bromine (50 mg) was added and the solution was stirred at 70° C. for 10 min. When the color of bromine disapeared, the mixture was evaporated to dryness. The residue was purified by silica gel column eluting with 30% EtOAc in hexane to give 85 mg of 2-bromo-1-(5-acetoxy-6,7-dimethyl-benzofuran-2-yl)-ethanone as a white solid. 1H NMR (CDCl3, 300 MHz) δ: 7.58 (s, 1H), 7.26 (s, 1H), 4.43 (s, 2H), 2.51, 2.37, 2.21 (3s, 9H) ppm. 13C NMR (CDCl3, 75 MHz) δ: 182.55, 170.13, 153.71, 150.74, 146.81, 131.21, 124.51, 122.92, 115.15, 113.28, 30.69, 21.27, 13.54, 12.80 ppm.

1. customthe mixture was evaporated to dryness
2. customThe residue was purified by silica gel column
3. washeluting with 30% EtOAc in hexane