反应详情

750 mg (2.9 mmol) of diethyl 2-(cyclohexylamino)vinylphosphonate, dissolved in 30 ml of dried tetrahydrofuran, are added dropwise at -5° C. under nitrogen to a suspension of 110 mg (3.6 mmol) of 80% pure sodium hydride in 15 ml of dry tetrahydrofuran. After 30 minutes, 810 mg (2.4 mmol) of the compound from Example 3 in 40 ml of dry tetrahydrofuran are added dropwise at the same temperature and the mixture is heated to reflux for 30 minutes. After cooling to room temperature, the mixture is added to 200 ml of ice-cold water and extracted three times with 100 ml of ethyl acetate each time. The combined organic phases are washed with saturated sodium chloride solution and dried over magnesium sulphate. After concentrating in vacuo, the residue is taken up in 70 ml of toluene, a solution of 4.5 g (3.5 mmol) of oxalic acid dihydrate in 30 ml of water is added and the mixture is heated to reflux for 30 minutes.

1. temperaturethe mixture is heated
2. temperatureto reflux for 30 minutes
3. extractionextracted three times with 100 ml of ethyl acetate each time
4. washThe combined organic phases are washed with saturated sodium chloride solution
5. dry with materialdried over magnesium sulphate
6. concentrationAfter concentrating in vacuo
7. temperaturethe mixture is heated
8. temperatureto reflux for 30 minutes