Methyl chloroformate → HCID 42633348, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of (2S,3S,5R)-2-benzyl-3-(3,5-bis-trifluoromethyl-benzylamino)-5-ethyl-pyrrolidine-1-carboxylic acid tert-butyl ester (0.0377 mmol; 20 mg) and cesium carbonate (0.113 mmol; 36.8 mg) in acetonitrile (0.38 mL) is added methyl chloroformate (0.0754 mmol; 5.9 mg) at room temperature. The reaction mixture is warmed to 80° C. and stirred for 3.5 hours. Additional methyl chloroformate (0.0754 mmol; 5.9 mg) is added to the mixture, and the mixture is stirred for additional 0.5 hours, and then cooled to room temperature. To the mixture is added brine and EtOAc. The organic layer is separated, dried over Na2SO4, filtered, and concentrated under reduced pressure. The residue is purified by preparative thin layer chromatography on silica gel (eluent: n-hexane/EtOAc) to give (2S,3S,5R)-2-Benzyl-3-[(3,5-bis-trifluoromethyl-benzyl)-methoxycarbonyl-amino]-5-ethyl-pyrrolidine-1-carboxylic acid tert-butyl ester (11.5 mg, 52%); ESI-MS m/z: 589 [M+1]+, Retention time 2.63 min (condition A).

Provenance & Evidence