Pyridine → N-(2-phenylethyl)cyclopropanamine

Participants

Reaction Steps

To a solution of cyclopropanamine (1 eq.) in dichloromethane (0.13 M) was added sequentially at 0° C. pyridine (1.5 eq.) and phenylacetyl chloride (9 eq.). The resulting mixture was slowly warmed to RT and stirred at RT for 3 h. After quenching with 1 N aq. HCl, the reaction mixture was extracted with EtOAc. The combined organic extracts were washed with sat. aq. NaHCO3 and brine, dried over MgSO4, filtered and the filtrate concentrated in vacuo. The crude amide thus obtained was taken up in THF (0.3 M) and added BH3.SMe2 complex (3 eq.). The reaction was heated to reflux and the volatiles were slowly distilled off. The resulting distillation residue was carefully quenched with 1 N aq. HCl and allowed to stir at 50° C. overnight. The reaction was cooled to 0° C. and the pH of the solution was brought to ˜12 with 1 N aq. NaOH before it was extracted with ether. The combined organic extracts were washed with brine, dried over MgSO4, filtered and the filtrate concentrated in vacuo. The crude product thus obtained could be further purified by way of column chromatography (SiO2, 2:1 (v/v) Hex:EtOAc→EtOAc) afforded the title compound as a colorless oil.

Provenance & Evidence