反应详情

A mixture of methyl 3-amino-2-([(benzyloxy)carbonyl]amino]propanoate trifluoroacetate (8.9 g) and triethylamine (30.6 ml) in dimethylformamide (89 ml) was treated by a slow dropwise addition of a solution of ethyl chloroacetate (7.8 ml) in dimethylformamide (20 ml). After stirring at room temperature for 12 hours, triethylamine (20.4 ml) was added again, and the mixture was treated by a slow dropwise addition of a solution of ethyl chloroacetate (5.2 ml) in dimethylformamide (15 ml) and stirred at room temperature for further 6 hours. The system was partitioned between water and ethyl acetate and the organic phase was washed with saturated brine, dried (MgSO2) and concentrated under reduced pressure. The residue was purified by a column chromatography on a silica gel (hexane:ethyl acetate=1:4) to obtain methyl 2-[[(benzyloxy)carbonyl]amino]-3-((2-ethoxy-2-oxoethyl)amino]propanoate (6.6 g) as a colorless oil.

1. stirringstirred at room temperature for further 6 hours
2. customThe system was partitioned between water and ethyl acetate
3. washthe organic phase was washed with saturated brine
4. dry with materialdried (MgSO2)
5. concentrationconcentrated under reduced pressure
6. customThe residue was purified by a column chromatography on a silica gel (hexane:ethyl acetate=1:4)