反应详情

To a solution of ethyl 2-methyl-4-(4-(methylsulfonyl)phenoxy)benzofuran-6-carboxylate (252d) (226 mg, 0.604 mmol) and NBS (183 mg, 1.03 mmol) in CHCl3 (10 mL) was added benzoyl peroxide (14.6 mg, 0.0604 mmol). After stirring the mixture at refluxed for 4 hr, the solvent was evaporated. The product was purified by gradient silica gel chromatography with hexanes/EtOAc (100/0 to 70/30) to give the title compound (200 mg, 73%) as a white solid. 1H NMR (300 MHz, CHLOROFORM-D) δ ppm 1.39 (t, J=7.16 Hz, 3 H) 3.07 (s, 3 H) 4.39 (q, J=7.16 Hz, 2 H) 4.53 (s, 2 H) 6.62 (s, 1 H) 7.05-7.18 (m, 2 H) 7.62 (d, J=0.75 Hz, 1 H) 7.86-7.98 (m, 2 H) 8.07 (d, J=0.75 Hz, 1 H).

1. temperatureat refluxed for 4 hr
2. customthe solvent was evaporated
3. customThe product was purified by gradient silica gel chromatography with hexanes/EtOAc (100/0 to 70/30)