反应详情

Step AI (3): 2-Bromo-5-methylbenzaldehyde (500 mg, 2.51 mmol) was dissolved in methanol (5.0 mL). p-Toluenesulfonic acid monohydrate (90 mg, 0.52 mmol) and trimethoxymethane (5 mL) were added. The reaction mixture was heated at reflux for 5 h. The reaction mixture was extracted with DCM and washed with saturated aqueous sodium bicarbonate. The combined organic phases were dried over Na2SO4, filtered and concentrated in vacuum to yield 1-bromo-2-(dimethoxymethyl)-4-methylbenzene (615 mg, 99%) as a colorless oil. LC-MS (M−OCH3)+=213.25. 1H NMR (CD3OD, 500 MHz) δ 7.41-7.39 (m, 2H) 6.98 (d, J=10 Hz, 1H) 5.51 (s, 1H) 3.37 (s, 6H) 2.30 (s, 3H).

1. temperatureThe reaction mixture was heated
2. temperatureat reflux for 5 h
3. extractionThe reaction mixture was extracted with DCM
4. washwashed with saturated aqueous sodium bicarbonate
5. dry with materialThe combined organic phases were dried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated in vacuum