4-Chlorobenzaldehyde → tert-Butyl (2-((4-chlorobenzyl)amino)ethyl)carbamate

Participants

Reaction Steps

The (2-amino-ethyl)-carbamic acid tert-butyl ester (5.00 g, 31.2 mmol) and 4-chloro-benzaldehyde (4.61 g, 32.77 mmol) were dissolved in 60 mL of 1,2-dichloroethane at room temperature. The reaction mixture was allowed to stir for 40 minutes prior to treatment with sodium triacetoxyborohydride (9.90 g, 46.8 mmol). The mixture was allowed to stir overnight to completion and quenched with a saturated NaHCO3 solution. The aqueous was extracted with DCM, separated, dried over MgSO4, and concentrated in vacuo. The residue was purified by chromatography (silica gel eluted with hexanes/EtOAc plus 2% triethyl amine) to afford the pure [2-(4-chlorobenzylamino)-ethyl]-carbamic acid tert-butyl ester as a viscous yellow oil (5.38 g, 61%). 1H NMR (CDCl3, 400 MHz) δ 7.29 (d, J=8.0 Hz, 2H), 7.25 (d, J=8.0 Hz, 2H), 4.92 (brs, 1H), 3.75 (s, 2H), 3.23 (appd, J=5.6 Hz, 2H), 2.73 (appt, J=6.0 Hz, 2H), 1.44 (s, 9H), 1.36 (brs, 1H). LCMS (APCI+) m/z 285 [M+H]+; Rt=2.30 min.

Provenance & Evidence