Ammonium Chloride → (3R,5R)-3-acetyl-5-(3,4,5-trifluorophenyl)morpholine-4-carboxylic acid benzyl ester

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Reaction Steps

A tetrahydrofuran solution (15 mL) of dimethyl sulfoxide (0.22 mL) was cooled to −78° C., and oxalyl chloride (246 μL) was added dropwise into the resultant solution. The reaction solution was stirred for 5 minutes at the same temperature, and a tetrahydrofuran (5 mL) solution of (3R,5R)-3-((R)-1-hydroxyethyl)-5-(3,4,5-trifluorphenyl)morpholin-4-carboxylic acid benzyl ester (880 mg) was added dropwise. The resultant reaction solution was stirred for 1 hour at the same temperature, and triethylamine (1.54 mL) was added. The reaction solution was returned to room temperature, and stirring was continued for 1 hour. Ammonium chloride aqueous solution and ethyl acetate were added to the reaction solution, and the organic layer was partitioned, and the resultant was dried over anhydrous magnesium sulfate. The solvent was removed under a vacuum, and the resultant was purified by silica gel column chromatography (heptane/ethyl acetate), and the title compound (800 mg) was obtained. The physical property values are as follows.

Provenance & Evidence