反应详情

温度

-78 °C

To a solution of the product from step 2 (1.0 g, 5.23 mmol) in methylene chloride (25 ml) was slowly added boron tribromide (2.00 ml, 15.7 mmol) at −78° C., and stirred at −78° C. for 1 h. After it was stirred at room temperature for 16 h, the reaction mixture was poured into ice-water. The product was collected on a filter, washed with ether to yield the product from step two (0.84 g, 84%). 1HNMR (400 MHz, CDCl3) δ 6.88 (d, J=8.8 Hz, 2H), 7.67 (d, J=3.2 Hz, 1H), 7.79 (d, J=8.8 Hz, 2H), 7.85 (d, J=3.2 Hz, 1H), MS (ESI−) m/z 176 (M−1).

1. customat −78° C.
2. stirringAfter it was stirred at room temperature for 16 h
3. customThe product was collected on a filter
4. washwashed with ether