反应详情

To a mixture of compound from step A (2 g, 8.61 mmol) and N-bromosuccinamide (1.84 g, 10.33 mmol) in carbon tetrachloride (50 ml) was added benzoyl peroxide (209 mg, 0.86 mmol) and the resulting mixture heated at reflux for 4 h. The reaction mixture cooled and filtered through celite, and filtrate evaporated. The residue purified by MPLC (Biotage Horizon: FLASH 40+s) eluent: 100% Hexanes (190 ml), gradient rising from 100% hexanes to 10% EtOAc in Hexanes (1000 ml), then 10% EtOAc in Hexanes (250 ml) to afford the title compound 2.04 g (76%). 1H NMR (CDCl3): 1.75 (s, 9H), 4.82 (s, 2H), 7.39 (m, 1H), 7.58 (m, 1H), 7.87 (d, J 8.0 Hz, 1H), 8.15 (d, J 8.5 Hz, 1H).

1. temperaturethe resulting mixture heated
2. temperatureat reflux for 4 h
3. temperatureThe reaction mixture cooled
4. filtrationfiltered through celite, and filtrate
5. customevaporated
6. customThe residue purified by MPLC (Biotage Horizon: FLASH 40+s) eluent