反应详情

A solution of 11 g (42 mmol) of diethyl 2-(cyclohexylamino)-vinyl-phosphonate in 60 ml of tetrahydrofuran are added dropwise under argon in the course of 10 min to a suspension of 2.52 g (84 mmol) of 80% strength sodium hydride in 60 ml of anhydrous tetrahydrofuran. 9.9 g (35 mmol) of the compound from Example VIII dissolved in 100 ml of tetrahydrofuran are added dropwise at reflux. The mixture is allowed to boil under reflux for 90 min and is cooled, treated with water and extracted several times with ethyl acetate. The combined organic phases are washed with saturated sodium chloride solution and concentrated in vacuo. The residue is dissolved in 300 ml of toluene and heated under reflux for 1 h with 22.9 g (182 mmol) of oxalic acid dihydrate in 350 ml of water. The mixture is cooled, the phases are separated and the aqueous phase is extracted twice with ethyl acetate. The combined organic phases are washed with saturated sodium chloride solution, dried over sodium sulphate and concentrated to dryness in vacuo. The residue is dissolved in dichloromethane and filtered through 400 g of silica gel 230-400 mesh in a glass suction filter. The mixture is eluted without sucking dry using petroleum ether/ethyl acetate 1:1, the eluate is concentrated in vacuo and the residue is stirred thoroughly in ether.

1. additionare added dropwise
2. temperatureat reflux
3. temperatureunder reflux for 90 min
4. temperatureis cooled
5. extractionextracted several times with ethyl acetate
6. washThe combined organic phases are washed with saturated sodium chloride solution
7. concentrationconcentrated in vacuo
8. dissolutionThe residue is dissolved in 300 ml of toluene
9. temperatureheated
10. temperatureThe mixture is cooled
11. customthe phases are separated
12. extractionthe aqueous phase is extracted twice with ethyl acetate
13. washThe combined organic phases are washed with saturated sodium chloride solution
14. dry with materialdried over sodium sulphate
15. concentrationconcentrated to dryness in vacuo
16. dissolutionThe residue is dissolved in dichloromethane
17. filtrationfiltered through 400 g of silica gel 230-400 mesh in a glass suction
18. filtrationfilter
19. washThe mixture is eluted
20. customwithout sucking dry
21. concentrationthe eluate is concentrated in vacuo