2,2,2-Trichloroethyl chloroformate → Ethyl 4-(3,4-dichlorophenyl)pyrrolidine-3-carboxylate
Reaction equation
[CH2:1]([O:3][C:4]([CH:6]1[CH:10]([C:11]2[CH:16]=[CH:15][C:14]([Cl:17])=[C:13]([Cl:18])[CH:12]=2)[CH2:9][N:8](CC2C=CC=CC=2)[CH2:7]1)=[O:5])[CH3:2].ClC(OCC(Cl)(Cl)Cl)=O>CC#N>[CH2:1]([O:3][C:4]([CH:6]1[CH:10]([C:11]2[CH:16]=[CH:15][C:14]([Cl:17])=[C:13]([Cl:18])[CH:12]=2)[CH2:9][NH:8][CH2:7]1)=[O:5])[CH3:2]Participants
4
Procedure
To a solution of (3SR,4RS)-1-benzyl-4-(3,4-dichloro-phenyl)-pyrrolidine-3-carboxylic acid ethyl ester 2.50 g (6.61 mmol) dissolved in CH3CN (55 mL) was added 1.34 mL (9.91 mmol) of 2,2,2-trichloroethyl chloroformate and stirring was continued for 4 hours at RT. Volatiles were removed under vacuo, and the residue was dissolved in AcOH (25 mL) before a total of 1.20 g of Zn dust was added portion wise. After three hours at RT, the reaction mixture was filtered on celite, the solvent removed under vacuo, followed by an extraction with EtOAc/aq. NaHCO3 (basic pH). The organic phases were dried on Na2SO4 and column chromatography (SiO2, CH2Cl2/MeOH 9:1) yielded 1.85 g (97%) of the title compound as a light yellow oil. ES-MS m/e: 288.1 (M+H+).