反应详情

2-Aminoethanol (1.62 mL, 26.9 mmol) and diethyl cyanophosphate (4.37 mL, 26.9 mmol) were added to a DMF (82 mL) solution of (2S)-2-{[(benzyloxy)carbonyl]amino}-3-[4-(trifluoromethoxy)phenyl]propanoic acid (9.37 g, 24.4 mmol) prepared in Reference Example 6 (6a), at room temperature. Then, to the resulting mixture was dropwise added a DMF (10 mL) solution of triethylamine (3.75 mL, 26.9 mmol) under ice-cooling with stirring over 45 minutes. The mixture was stirred at room temperature for 3 hours, and ethyl acetate (480 mL) was added to this reaction solution. The mixture was sequentially washed with water (480 mL, four times), 1 N sodium hydroxide, water, and saturated brine. The organic layer was dried over anhydrous sodium sulfate, and the solvent was evaporated. The residue was dried under reduced pressure to give 9.36 g of the title compound (white powder, yield: 90%).

1. temperaturecooling
2. stirringThe mixture was stirred at room temperature for 3 hours
3. washThe mixture was sequentially washed with water (480 mL, four times), 1 N sodium hydroxide, water, and saturated brine
4. dry with materialThe organic layer was dried over anhydrous sodium sulfate
5. customthe solvent was evaporated
6. customThe residue was dried under reduced pressure