反应详情

A solution of Br2 (1.12 mL, 21.8 mmol) in CCl4 was added dropwise to a stirred and cooled (0° C.) solution of 8 (7.10 g, 21.8 mmol) and pyridine (2.1 mL, 26.2 mmol) in dry CHCl3 (330 mL). Progress of the reaction was followed by TLC. When the reaction was completed, aqueous NaHCO3—Na2S2O3 solution was added. The organic solution was separated and the aqueous layer was extracted with CH2Cl2 (3×100 mL). Combined organic solutions were dried (MgSO4), concentrated and purified by SGC with hexane:benzene as eluent in gradient (up to 14% benzene) to afford 9 (8.47 g, 91%) as tan solid. 1H NMR (400 MHz, CDCl3) δ 0.65 (s, 6H), 0.97 (s, 9H), 7.02-7.10 (m, 1H), 7.29 (s, 1H), 7.33-7.38 (m, 1H), 7.40-7.47 (m, 2H), 7.97 (d, J=2.2 Hz, 1H), 8.51 (d, J=2.2 Hz, 1H).

1. customThe organic solution was separated
2. extractionthe aqueous layer was extracted with CH2Cl2 (3×100 mL)
3. dry with materialCombined organic solutions were dried (MgSO4)
4. concentrationconcentrated
5. custompurified by SGC with hexane