反应详情

A suspension of 128 g of diethoxymethyl(benzyl)phosphinic acid ethyl ester in 400 ml of hydrochloric acid is heated under reflux for 20 hours, cooled to room temperature, washed with diethyl ether/hexane (1:1) and concentrated to dryness by evaporation. The residue is taken up in dichloromethane, dried over sodium sulfate and again concentrated by evaporation. The viscous benzylphosphinic acid that remains is then dried under a high vacuum. 13.34 g of benzylphosphinic acid are dissolved in 150 ml of dichloromethane, the solution is cooled to 5°, and 8.64 g of triethylamine are added dropwise. An exothermic reaction takes place. The mixture is cooled to 5° again, and 9.3 g of chloroformic acid ethyl ester are added dropwise within a period of 30 minutes. A precipitate forms in an exothermic reaction with the evolution of gas. The mixture is allowed to warm to room temperature and is then stirred at room temperature for 3 hours, taken up in dichloromethane and washed with water, and the organic solvent is removed. The crude product is distilled under a high vacuum, yielding benzylphosphinic acid ethyl ester having a boiling point of 96°100° (5×10-6 bar).

1. temperatureis heated
2. temperatureunder reflux for 20 hours
3. washwashed with diethyl ether/hexane (1:1)
4. concentrationconcentrated to dryness by evaporation
5. dry with materialdried over sodium sulfate
6. concentrationagain concentrated by evaporation
7. dry with materialThe viscous benzylphosphinic acid that remains is then dried under a high vacuum
8. dissolution13.34 g of benzylphosphinic acid are dissolved in 150 ml of dichloromethane
9. temperaturethe solution is cooled to 5°
10. addition8.64 g of triethylamine are added dropwise
11. customAn exothermic reaction
12. temperatureThe mixture is cooled to 5° again
13. customA precipitate forms in an exothermic reaction with the evolution of gas
14. temperatureto warm to room temperature
15. washwashed with water
16. customthe organic solvent is removed
17. distillationThe crude product is distilled under a high vacuum