Carbon tetrabromide → HCID 69173780, compound

Participants

Reaction Steps

At 0° C., to a solution of tert-butyl (3S)-4-chloro-3-(3-hydroxypropan-1-yl)-5-oxo-1-[(1R)-1-phenylethyl]pyrrolidine-3-carboxylic acid (500 mg, 1.31 mmol) in dichloromethane (10 mL) were added carbon tetrabromide (434 mg, 1.31 mmol) and triphenylphosphine (344 mg, 1.31 mmol). After stirring the mixture for 2 hours at room temperature, carbon tetrabromide (143 mg, 0.431 mmol) and triphenylphosphine (114 mg, 0.434 mmol) were added to the mixture. After stirring for 2 hours, carbon tetrabromide (72 mg, 0.216 mmol) and triphenylphosphine (57 mg, 0.217 mmol) were added and the mixture was stirred for 16 hours. The solvent was distilled off under reduced pressure. The residue was purified by short silica gel flush column chromatography (15% ethyl acetate/hexane) to afford a colorless oil. Under nitrogen atmosphere, to a solution of this oil in THF (12 mL) was added 1.0M lithium bis(trimethylsilyl)amide in THF solution (1.46 mL, 1.46 mmol) at −78° C., and the reaction mixture was warmed to 0° C. over 2 hours. To the mixture were added saturated aqueous solution of ammonium chloride and ethyl acetate. The separated organic layer was washed with water and brine. The solution was dried over anhydrous sodium sulfate and the solvent was distilled off under reduced pressure. The residue was purified by silica gel flush column chromatography (15% ethyl acetate/hexane) to afford 337 mg of the title compound as a pale yellow solid.

Provenance & Evidence