反应详情

To a solution of diethyl 3-(N-ethoxycarbonyl-N-ethoxycarbonyloxyamino)-2-hydroxypropylphosphonate (24.0 g.) in methylene chloride (50 ml.) was added dropwise trimethylbromosilane (41 ml.) under ice-cooling, whereafter the mixture was stirred for half an hour at the same temperature and then for additional 2.5 hours at ambient temperature. After the reaction was completed, the chloroform and the excess of the trimethylbromosilane was distilled off from the reaction mixture under reduced pressure to give a residue, which was dissolved in water (125 ml.) and stirred for an hour at ambient temperature. This aqueous solution was washed three times with chloroform (each 30 ml. portion) and evaporated to dryness under reduced pressure to give a residue, which was dissolved in 1 N hydrochloric acid (240 ml.) and heated to reflux for 15 hours. The resultant aqueous solution was evaporated to dryness under reduced pressure to give a residue, which was dissolved in water (60 ml.), decolorized with activated charcoal (500 mg.) and evaporated to dryness under reduced pressure. The residue thus obtained was dissolved in a mixture of water (20 ml.) and methanol (40 ml.), and adjusted to pH 3-4 with propylene oxide (about 25 ml.) to precipitate oily materials. Furthermore, to this solution was added ethanol (80 ml.) and allowed to stand for a while in order to precipitate said materials completely, and these materials were collected by decantation and dissolved in water (20 ml.). The insoluble materials were removed by filtration, and to the filtrate was added methanol (35 ml.) at 50°-60° C. The resultant solution was allowed to stand for 3.5 hours at ambient temperature, and precipitating crystals were collected by filtration, washed twice with methanol (10 ml.) and dried on phosphorus pentoxide to give 2-hydroxy-3-(N-hydroxyamino)propylphosphonic acid (5.9 g.).

1. temperaturecooling, whereafter the mixture
2. distillationthe chloroform and the excess of the trimethylbromosilane was distilled off from the reaction mixture under reduced pressure
3. customto give a residue, which
4. stirringstirred for an hour at ambient temperature
5. washThis aqueous solution was washed three times with chloroform (each 30 ml
6. customportion) and evaporated to dryness under reduced pressure
7. customto give a residue, which
8. temperatureheated
9. temperatureto reflux for 15 hours
10. customThe resultant aqueous solution was evaporated to dryness under reduced pressure
11. customto give a residue, which
12. customevaporated to dryness under reduced pressure
13. customThe residue thus obtained
14. customto precipitate oily materials
15. additionFurthermore, to this solution was added ethanol (80 ml.)
16. customto precipitate
17. customthese materials were collected by decantation
18. dissolutiondissolved in water (20 ml.)
19. customThe insoluble materials were removed by filtration
20. additionto the filtrate was added methanol (35 ml.) at 50°-60° C
21. waitto stand for 3.5 hours at ambient temperature
22. customprecipitating crystals
23. filtrationwere collected by filtration
24. washwashed twice with methanol (10 ml.)
25. customdried on phosphorus pentoxide