反应详情

Bubble hydrogen chloride gas through a solution of [4-(cyclopropylcarbonyl)phenyl]methyl-propanedioic acid, diethyl ester (570 mg, 2.0 mmol) in ethanol (4 mL) for 5 minutes. Heat the solution to reflux. After 18 hours, cool the solution to room temperature and bubble nitrogen through the solution for 1 hour. Add ethyl acetate and water to the residue. Dry the organic phase over anhydrous magnesium sulfate and concentrate. Dissolve the crude product in ethanol (50 mL) and bubble hydrogen chloride gas through the solution for 10 minutes. Heat the solution to reflux. After stirring 2 days, concentrate the solution. Add water and ethyl acetate to the residue. Dry the organic phase over anhydrous magnesium sulfate and concentrate. Purify by flash chromatography (150 g silica gel, 20% ethyl acetate/heptane as eluent) to give the title compound (409 mg, 59%).

1. temperatureHeat the solution
2. temperatureto reflux
3. custombubble nitrogen through the solution for 1 hour
4. dry with materialDry the organic phase over anhydrous magnesium sulfate
5. concentrationconcentrate
6. dissolutionDissolve the crude product in ethanol (50 mL)
7. custombubble hydrogen chloride gas through the solution for 10 minutes
8. temperatureHeat the solution
9. temperatureto reflux
10. concentrationconcentrate the solution
11. dry with materialDry the organic phase over anhydrous magnesium sulfate
12. concentrationconcentrate
13. customPurify by flash chromatography (150 g silica gel, 20% ethyl acetate/heptane as eluent)