反应详情

BBr3 (26 mL, 1.0 M in heptane, 25.9 mmol, 3.0 Eq.) was added dropwise to a stirred solution of 5-Bromo-3-methoxy-thiophene-2-carboxylic acid methyl ester (2.17 g, 8.62 mmol, 1.0 Eq.) in anhydrous DCM (100 mL) at −10° C. under nitrogen. After 1.5 hours, water (40 mL) was added and the aqueous layer extracted with DCM (3×20 mL). The combined organic extracts were dried (MgSO4) and concentrated in vacuo. The crude product was purified by column chromatography (50% Petroleum ether/DCM) to give the sub-title compound as a white solid (1.67 g, 7.04 mmol, 81%); 1H NMR (400 MHz, CDCl3) δ 3.90 (3H, s), 6.80 (1H, s), 9.68 (1H, br s).

1. extractionthe aqueous layer extracted with DCM (3×20 mL)
2. dry with materialThe combined organic extracts were dried (MgSO4)
3. concentrationconcentrated in vacuo
4. customThe crude product was purified by column chromatography (50% Petroleum ether/DCM)