反应详情

A solution of boron trichloride (50 mL, 1.0 M solution in CH2Cl2) was slowly added to a solution of 2,4,5-trimethoxybenzaldehyde (3.92 g, 20 mmol) in CH2Cl2 (200 mL) at −78° C. (dry ice/acetone bath). The mixture was warmed to room temperature and stirred for three hours. 10 mL of HCl (37%) aqueous solution was poured into the resulting solution at 0° C. and extracted with CH2Cl2 (150 mL×3). The combined organic layer was washed with saturated aqueous NaCl (200 mL×2), water (100 mL×1), dried over MgSO4, and evaporated to afford 3.72 g of a light brown solid (3.72 g, 99%): 1H-NMR (400 MHz, CDCl3) δ3.88 (s, 3H), 3.94 (s, 3H), 6.47 (s, 1H), 6.91 (s, 1H), 9.70 (s, 1H).

1. extractionextracted with CH2Cl2 (150 mL×3)
2. washThe combined organic layer was washed with saturated aqueous NaCl (200 mL×2), water (100 mL×1)
3. dry with materialdried over MgSO4
4. customevaporated