Benzyl Bromide → trans-4-(Dibenzylamino)cyclohexanol

Participants

Reaction Steps

trans-4-Aminocyclohexanol hydrochloride (25 g, 217 mmol) was suspended in acetonitrile (500 mL). Benzyl bromide (54.2 mL, 456 mmol) and potassium carbonate (120 g, 868 mmol) were added to the suspension and the resulting mixture was stirred vigorously overnight at room temperature. The reaction mixture was filtered through a plug of celite and the plug was washed thoroughly with acetonitrile. The filtrate was condensed to give a white solid. The crude solids were purified by silica gel chromatography (0-60% ethyl acetate in hexanes). Pure product containing fractions were combined and concentrated to afford (1r,4r)-4-(dibenzylamino)cyclohexanol (25 g, 85 mmol, 39.0% yield) as a white solid. 1H NMR (400 MHz, DMSO-d6) δ ppm 7.26-7.36 (m, 8H), 7.16-7.22 (m, 2H), 4.43 (d, J=4.69 Hz, 1H), 3.55 (s, 4H), 3.27-3.33 (m, 1H), 2.28-2.40 (m, 1H), 1.69-1.88 (m, 4H), 1.40 (qd, J=12.56, 2.93 Hz, 2H), 0.89-1.05 (m, 2H); MS (ESI) m/z 296.3 [M+1]+.

Provenance & Evidence