反应详情

温度

-20 °C

Boc-Leu-Leu-OH (Bachem, 43.6 mmol) is dissolved in THF (250 ml) and N-methylmorpholine (43.6 mmol) is added. The mixture is cooled to −20° C. and isobutyl chloroformate (43.6 mmol) is added dropwise. The mixture is stirred for 10 min. and then a 25% aqueous solution of ammonia (52.3 mmol) is added at −20° C. The mixture is stirred for 3 hours at −20° C. to −10° C. After evaporation of the solvent, the residue is extracted with ethyl acetate. The extract is washed with water and dried over magnesium sulfate and evaporated. The crude product is suspended in diethylether and the solid filtered of and dried (vacuum). 14.2 g of a white powder with mp. 155-156° C., Rf=0.5 (CH2Cl2/MeOH=9:1) is obtained.

1. stirringThe mixture is stirred for 3 hours at −20° C. to −10° C
2. customAfter evaporation of the solvent
3. extractionthe residue is extracted with ethyl acetate
4. washThe extract is washed with water
5. dry with materialdried over magnesium sulfate
6. customevaporated
7. filtrationthe solid filtered of and
8. customdried (vacuum)