反应详情

814 mg (20.36 mmol) of sodium hydride are added in portions (caution: evolution of hydrogen) to a solution of 5 g (27.15 mmol) of diallyl malonate in 25 ml of dioxane at 0° C. The mixture is warmed to room temperature and then stirred at 40° C. for 30 minutes. Subsequently, at 40° C., 3.3 g (13.57 mol) of methyl 4-(2-bromoethyl)benzoate, dissolved in 25 ml of dioxane, are slowly added dropwise, and the reaction solution is stirred at 110° C. overnight. After cooling to room temperature, the reaction mixture is added to 120 ml of saturated ammonium chloride solution. The mixture is extracted three times with ethyl acetate, and the combined organic phases are washed with saturated sodium chloride solution and dried over sodium sulfate. After filtration, the solvent is concentrated to dryness in vacuo. Excess diallyl malonate is then removed by high vacuum distillation (boiling point: 57° C.; 0.074 mbar). The distillation residue is purified by flash chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 9:1→1:1). 2.8 g (26% of theory) of a colorless solid are obtained.

1. additionare slowly added dropwise
2. stirringthe reaction solution is stirred at 110° C. overnight
3. temperatureAfter cooling to room temperature
4. extractionThe mixture is extracted three times with ethyl acetate
5. washthe combined organic phases are washed with saturated sodium chloride solution
6. dry with materialdried over sodium sulfate
7. filtrationAfter filtration
8. concentrationthe solvent is concentrated to dryness in vacuo
9. customExcess diallyl malonate is then removed by high vacuum distillation (boiling point: 57° C.; 0.074 mbar)
10. distillationThe distillation residue is purified by flash chromatography on silica gel (mobile phase: cyclohexane/ethyl acetate 9:1→1:1)
11. custom2.8 g (26% of theory) of a colorless solid are obtained