Oxalyl chloride → HCID 89668612, compound

Participants

Reaction Conditions

Reaction Steps

Oxalyl chloride (1.17 mL, 13.3 mmol) was added dropwise to a solution of (S)-1-(((9H-fluoren-9-yl)methoxy)carbonyl)pyrrolidine-2-carboxylic acid (Fmoc-Pro-OH) (3.00 g, 8.89 mmol) and N,N-dimethylformamide (34 μL, 0.445 mmol) in methylene chloride (36 mL) with stirring at 0° C. under a nitrogen atmosphere, and the reaction mixture was then stirred at room temperature for 1 hour. The reaction solution was concentrated under reduced pressure, the resulting residue was mixed with methylene chloride (36 mL), N-ethyldiisopropylamine (DIPEA) (2.33 mL, 13.3 mmol) and (R)-2-hydroxy-3-phenylpropanoic acid (2.22 g, 13.3 mmol) at 0° C., and the reaction mixture was stirred at room temperature for 2 hours. The reaction solution was washed with 1 N hydrochloric acid twice and a saturated aqueous sodium chloride solution twice, dried over sodium sulfate and then concentrated under reduced pressure. The resulting residue was purified by reverse-phase silica gel column chromatography (0.1% aqueous formic acid solution/0.1% formic acid-acetonitrile solution) to afford (R)-2-(((S)-1-(((9H-fluoren-9-yl)methoxy)carbonyl)pyrrolidine-2-carbonyl)oxy)-3-phenylpropanoic acid (Fmoc-Pro-D-PhLac-OH) (Compound SP635) (3.20 g, 6.59 mmol, 74%).

Provenance & Evidence