反应详情

To 4-hydroxybenzaldehyde (20 g, 0.164 mol) in acetone (300 mL) was added K2CO3 (34 g, 1.5 equiv.) and the reaction was stirred at room temperature during 30 minutes. Ethyl 2-bromo-2-methylpropionate (36.2 mL, 1.5 equiv.) was added dropwise and the mixture was heated under reflux during 3 hours. K2CO3 (34 g, 1.5 equiv.) and ethyl 2-bromo-2-methylpropionate (36.2 mL, 1.5 equiv.) were added and the mixture was heated under reflux during 16 hours and then pourred into water and extracted with CH2Cl2 (3×300 mL). The combined organic layers were dried over Na2SO4, filtered and the solvent evaporated to afford crude intermediate. After chromatography on silicagel, eluting with cyclohexane/CH2Cl2 (6/4, then 8/2) and then with CH2Cl2, the titled compound was obtained as an oil (27 g, 69.85%)

1. temperaturethe mixture was heated
2. temperatureunder reflux during 3 hours
3. temperaturethe mixture was heated
4. temperatureunder reflux during 16 hours
5. extractionextracted with CH2Cl2 (3×300 mL)
6. dry with materialThe combined organic layers were dried over Na2SO4
7. filtrationfiltered
8. customthe solvent evaporated
9. customto afford crude intermediate
10. washAfter chromatography on silicagel, eluting with cyclohexane/CH2Cl2 (6/4