1-Chloroethyl chloroformate → Rel-tert-butyl ((3R,4S)-4-(3,4-dichlorophenyl)pyrrolidin-3-yl)(methyl)carbamate

Participants

Reaction Steps

To a solution of rac-[(3R,4S)-1-benzyl-4-(3,4-dichloro-phenyl)-pyrrolidin-3-yl]-methyl-carbamic acid tert-butyl ester (3.50 g, 8.04 mmol) in toluene (50 mL) was added under an atmosphere of nitrogen N,N-diisopropyl ethyl amine (1.86 mL, 10.9 mmol). The flask was cooled with a water bath and 1-chloroethyl chloroformate (1.14 mL, 10.5 mmol) was added during 2 min. After stirring for 2 h at ambient temperature the solution stood over night at 5° C. The reaction mixture was concentrated in vacuo. After the addition of methanol (50 mL) it was stirred for 4 h at ambient temperature. Concentration afforded the title compound (2.95 g, 99%) as a light brown oil. MS m/e: 345.1 [M+H]+.

Provenance & Evidence