反应详情

To a stirred suspension of (S)—N-benzyloxycarbonyl-L-tryptophan 1a (2.45 g, 7.2 mmol) in 10 ml anhydrous CH2Cl2, was added DMAP (0.1 g, 0.82 mmol) and methanol (0.28 g, 11.8 mmol). At 0° C., DCC in CH2Cl2 solution was slowly added to the mixture and then it was allowed to warm to room temperature and stirred overnight. After twice filtration and evaporation, the residue was purified by flash column chromatography (n-hexane/EA, 4:1 to 2:1) and afforded the desired product (S)-2a as a colourless oil (2.5 g, 98%).

1. filtrationAfter twice filtration and evaporation
2. customthe residue was purified by flash column chromatography (n-hexane/EA, 4:1 to 2:1)