Acetic Anhydride → (2S,3S,5R)-5-[(1S,2S)-2-Acetylamino-3-(3-fluoro-5-hydroxy-phenyl)-1-hydroxypropyl]-3-methyl-2-(2,2,2-trifluoro-ethoxy)-morpholine-4-carboxylic acid tert-butyl ester

Participants

Reaction Steps

Add acetic anhydride (0.142 mL, 1.51 mmol) to an ice cold solution of (2S,3S,5R)-5-[(1S,2S)-2-Amino-3-(3-fluoro-5-hydroxy-phenyl)-1-hydroxy-propyl]-3-methyl-2-(2,2,2-trifluoro-ethoxy)-morpholine-4-carboxylic acid tert-butyl ester (823 mg, 1.43 mmol) in dichloromethane (9 mL). Stir for 50 minutes and add diisopropylethylamine (0.125 mL, 0.717 mmol) and stir for 2 hours. Quench with aqueous 1N hydrochloric acid, wash with saturated aqueous sodium bicarbonate, dry with magnesium sulfate and purify on silica gel with dichloromethane/ethyl acetate mixtures to give the desired compound (493 mg). MS(ESI): m/z=525 [M+H]+.

Provenance & Evidence