反应详情

A mixture of 7.4 g of Fmoc-Gln-OH (20 mmol) and 10.4 g of triphenylmethanol (40 mmol) in 300 ml of acetic acid is stirred at 100° for 10 minutes. After the addition of 0.1 ml of concentrated sulfuric acid the whole is stirred at 100° for a further 15 minutes, a clear yellow solution forming. This is concentrated by evaporation under reduced pressure at 60°, and the residue is dried under reduced pressure for 10 minutes. The solid residue is dissolved in 60 ml of acetic acid at 60°, left at 60° for 20 minutes, then 2 ml of acetic anhydride (20 mmol) are added and after 1 hour at 60° the whole is concentrated by evaporation under reduced pressure. The oily residue is dried for 10 minutes at 60°, then dissolved in 100 ml of acetic acid and introduced dropwise into 500 ml of ice-cold water. The precipitate is isolated by filtration, washed well with water and dissolved in ethyl acetate; the aqueous phase is separated off and the organic phase is washed with a saturated aqueous sodium chloride solution. After drying over sodium sulfate, the organic solution is concentrated to dryness by evaporation, the residue is dissolved in 50 ml of 1,2-dichloroethane and applied to 100 g of silica gel; elution is carried out with 1,2-dichloroethane and with 1,2-dichloroethane containing 2%, then 4%, methanol. The fractions containing the Fmoc-Gln(Trt)-OH are concentrated by evaporation under reduced pressure, and the product is crystallised from a mixture of ethyl acetate and diisopropyl ether, m.p. from 125°.

1. stirringis stirred at 100° for a further 15 minutes
2. customa clear yellow solution forming
3. concentrationThis is concentrated by evaporation under reduced pressure at 60°
4. customthe residue is dried under reduced pressure for 10 minutes
5. dissolutionThe solid residue is dissolved in 60 ml of acetic acid at 60°
6. waitleft at 60° for 20 minutes
7. concentrationis concentrated by evaporation under reduced pressure
8. customThe oily residue is dried for 10 minutes at 60°
9. dissolutiondissolved in 100 ml of acetic acid
10. additionintroduced dropwise into 500 ml of ice-cold water
11. customThe precipitate is isolated by filtration
12. washwashed well with water
13. dissolutiondissolved in ethyl acetate
14. customthe aqueous phase is separated off
15. washthe organic phase is washed with a saturated aqueous sodium chloride solution
16. dry with materialAfter drying over sodium sulfate
17. concentrationthe organic solution is concentrated to dryness by evaporation
18. dissolutionthe residue is dissolved in 50 ml of 1,2-dichloroethane
19. washelution
20. additionThe fractions containing the Fmoc-Gln(Trt)-OH
21. concentrationare concentrated by evaporation under reduced pressure
22. customthe product is crystallised from a mixture of ethyl acetate and diisopropyl ether
23. customm.p. from 125°