反应详情

温度

0 °C

A mixture of 5 (1.39 g, 4.23 mmol), N-bromosuccinimide (0.75 g, 4.23 mmol) and AIBN (33 mg, 0.2 mmol) in CCl4 (70 mL) was refluxed for 15 hours under a flow of dry N2 gas. The reaction mixture was cooled to 0° C. and the precipitate was removed by filtration while maintaining the temperature at 0° C. After the solvent was evaporated, the residue was washed with small amount of ethanol several times to afford a pinkish solid 6 (1.14 g, 66%): 1H-NMR (500 MHz, CDCl3) δ3.60 (s, 3H), 3.97 (s, 3H), 3.99 (s, 3H), 4.96 (s, 2H), 5.31 (s, 2H), 6.85 (s, 1H), 7.30 (t, 1H, J=8.0 Hz), 7.40 (d, 1H, J=8.0 Hz), 7.51 (d, 1H, J=8.0 Hz), 7.66 (s, 1H).

1. customthe precipitate was removed by filtration
2. temperaturewhile maintaining the temperature at 0° C
3. customAfter the solvent was evaporated
4. washthe residue was washed with small amount of ethanol several times