Benzaldehyde → N-Benzyl-N'-boc-ethylenediamine

Reaction equation

[NH2:1][CH2:2][CH2:3][NH:4][C:5](=[O:11])[O:6][C:7]([CH3:10])([CH3:9])[CH3:8].[CH:12](=O)[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1.[O-]S([O-])(=O)=O.[Mg+2].CCN(CC)CC>>[CH2:12]([NH:1][CH2:2][CH2:3][NH:4][C:5](=[O:11])[O:6][C:7]([CH3:8])([CH3:10])[CH3:9])[C:13]1[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=1

Participants

Reactant 4

HCID 240Benzaldehyde

HCID 8471Triethylamine

HCID 24083Sulfuric acid magnesium salt (1:1)

HCID 187201N-BOC-ethylenediamine

Product 1

HCID 10634443N-Benzyl-N'-boc-ethylenediamineYield 25.1%

Procedure

To a solution of tert-butyl 2-aminoethylcarbamate (3.7 g, 22.3 mmol), benzaldehyde (2.36 g, 22.3 mmol) and MgSO4 (1.33 g) in 1,2-dicholoroethane (300 mL) and Et3N (3.1 mL, 22.3 mmol) at RT was added NaHB(AcO)3. The mixture was stirred (RT, 16 h) and filtered. The solution was washed with saturated aqueous NaHCO3 (200 mL), dried over MgSO4 and concentrated under reduced pressure. The crude product was purified by chromatography on silica gel, eluting with MeOH-DCM (0-10%) to afford tert-butyl 2-(benzylamino)ethylcarbamate (1.4 g, 23%). Mass calculated for C14H22N2O2=250.34; found: [M+H]+=251.3.