反应 #6712

反应方程式

dicyclohexylcarbodiimide

Boc-Pro-Ile-OH

N-hydroxybenzotriazole

thiazolidine

→

H-Pro-Ile

收率 80.0%

溶剂

ethyl acetate

dichloromethane

反应条件

后处理

1. 1
   workup.STIRRINGStirring
2. 2
   过滤the solution is thoroughly filtered off from the dicyclohexylurea that
3. 3
   其他is precipitated out
4. 4
   其他the residue obtained
5. 5
   洗涤The ethyl acetate solution is washed at least three times with saturated bicarbonate solution, once with saturated NaC1 solution, three times with dilute KHSO4 solution and again with NaC1 solution
6. 6
   干燥The ethyl acetate phase is dried over Na2SO4
7. 7
   浓缩concentrated
8. 8
   其他a rotary evaporator
9. 9
   其他the remaining crude product is recrystallised
10. 10
    其他Boc-Pro-Ile-Thia crystallises after 1–2 days at 4° C. (yield 80%)
11. 11
    workup.ADDITION1.1N HC1/glacial acetic acid solution is added to Boc-Pro-Ile-Thia (3 ml per mmol of peptide)
12. 12
    workup.STIRRINGStirring
13. 13
    workup.WAITis carried out for two hours at RT
14. 14
    workup.ADDITIONabsolute ether is added
15. 15
    其他excess removal solution is evaporated off
16. 16
    其他a rotary evaporator
17. 17
    其他The hydrochloride crystallises quantitatively under absolute ether overnight at 4° C
18. 18
    其他The crystals are quickly separated off by suction filtration
19. 19
    洗涤washed several times with absolute ether
20. 20
    其他the product is stored in a desiccator over KOH or phosphorus pentoxide

实验过程

6.5 mM Boc-Pro-Ile-OH (one equivalent=1 eq.) is suspended, together with N-hydroxybenzotriazole (1 eq.) and thiazolidine (1 eq.), in 30 ml of dichloromethane (DCM). The equivalent amount of 1M dicyclohexylcarbodiimide solution is added dropwise, at −10° C., with stirring. Stirring is carried out at −10° C. and overnight at room temperature. For the purpose of working-up, the solution is thoroughly filtered off from the dicyclohexylurea that is precipitated out, DCM is drawn off in vacuo and the residue obtained is taken up in ethyl acetate. The ethyl acetate solution is washed at least three times with saturated bicarbonate solution, once with saturated NaC1 solution, three times with dilute KHSO4 solution and again with NaC1 solution. The ethyl acetate phase is dried over Na2SO4 and concentrated using a rotary evaporator, and the remaining crude product is recrystallised using ethyl acetate/pentane. Boc-Pro-Ile-Thia crystallises after 1–2 days at 4° C. (yield 80%). 1.1N HC1/glacial acetic acid solution is added to Boc-Pro-Ile-Thia (3 ml per mmol of peptide). Stirring is carried out for two hours at RT, absolute ether is added and excess removal solution is evaporated off using a rotary evaporator. The hydrochloride crystallises quantitatively under absolute ether overnight at 4° C. The crystals are quickly separated off by suction filtration, washed several times with absolute ether, and the product is stored in a desiccator over KOH or phosphorus pentoxide.

来源