Citric Acid → HCID 50916498, compound

Participants

Reaction Conditions

Reaction Steps

Ethylmagnesium bromide 3 M in ether (2 mL, 6.2 mmol) was added slowly to a solution of cyclopropyl acetylene (0.41 g, 6.2 mmol) in THF (5 mL) in an ice-bath under argon. The mixture was stirred at 0° C. for 1 hour and then 40° C. for 2 hours. Then (R)-2-(4-chloro-2-(2,2,2-trifluoroacetyl)phenylamino)-2-oxo-1-phenylethyl pivalate (12, 0.55 g, 1.24 mmol) in THF (2 mL) was added slowly in an ice-bath. The mixture was stirred at 0° C. for 1.5 hours. 10% Citric acid was added to quench the reaction. The organic layer was washed with water and then evaporated to dryness to give (R)-2-(4-chloro-2-((S)-4-cyclopropyl-1,1,1-trifluoro-2-hydroxybut-3-yn-2-yl)phe nylamino)-2-oxo-1-phenylethyl pivalate (13). This solid was shown to be 35.9% de by chiral HPLC. The pure product was isolated by chromatography.

Provenance & Evidence