反应详情

A solution of 75 2-(4-Hydroxy-phenyl)-benzofuran-5-ol (0.65 g, 2.9 mmol) in CH3CN (40 mL) was treated with K2CO3 (1 g, 7.1 mmol) followed by portionwise addition of NBS (0.36 g, 2.0 mmol). After stirring for approximately 30 minutes, the reaction was worked up by addition of 2 N HCl followed by 10% Na2SO3aq. and then the CH3CN was stripped off. The aqueous layer was extracted with EtOAc and washed with brine and dried over MgSO4. The reaction mixture was concentrated and chromatographed on silica gel (EtOAc/hexanes; 1:4): Mp 196-198° C.; 1H NMR (DMSO-d6) δ 9.93 (br s, 2 H), 7.76 (d, 2H, J=8.5 Hz), 7.40 (d, 1 H, J=8.7 Hz), 7.04 (s, 1 H), 6.87 (dd, 2 H, J=9.0 Hz, 3.1 Hz); MS 305/307 (M+H)+.

1. extractionThe aqueous layer was extracted with EtOAc
2. washwashed with brine
3. dry with materialdried over MgSO4
4. concentrationThe reaction mixture was concentrated
5. customchromatographed on silica gel (EtOAc/hexanes; 1:4)