反应详情

To a solution of 1,2-dimethoxy-3-methyl-benzene (13.8 g, 76.66 mmol) cooled to −30° C. (dry ice/acetone) in dichloromethane (200 mL) was added boron trichloride (230 mL, 230 mmol) dropwise and the mixture was left to stir overnight at room temperature. The solution was cooled to 0° C. and ice/water was added carefully, and then extracted with excess of dichloromethane. The organic layer was washed with water, dried (Na2SO4) and the solvent was evaporated. Purification by silica gel column chromatography (10-20% EtOAc/hexane) gave the title compound as a crystalline solid: yield 9.2 g (80%). 1H NMR (400 MHz, CDCl3) δ (ppm): 11.11 (s, 1H), 9.82 (s, 1H), 7.05 (d, J=8.2 Hz, 1H), 6.81 (d, J=8.6 Hz, 1H), 5.67 (s, 1H), 2.33 (s, 3H).

1. waitthe mixture was left
2. temperatureThe solution was cooled to 0° C.
3. extractionextracted with excess of dichloromethane
4. washThe organic layer was washed with water
5. dry with materialdried (Na2SO4)
6. customthe solvent was evaporated
7. customPurification by silica gel column chromatography (10-20% EtOAc/hexane)