Ethanolamine → benzyl (1S)-2-[(2-hydroxyethyl)amino]-2-oxo-1-[4-(trifluoromethoxy)benzyl]ethylcarbamate

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Reaction Steps

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%).

Provenance & Evidence