Under argon protection, 2-(cyclohex-1-en-1-yl)ethylamine (500 mg, 4.00 mmol) was dissolved in methanol (10 mL) and 10% Pd/C (50 mg) was added. The reaction system was placed at 50°C, switched to hydrogen atmosphere (balloon pressure), and the reaction was stirred at room temperature for 16 hours. The reaction progress was monitored by thin layer chromatography (TLC). After completion of the reaction, the reaction mixture was filtered through diatomaceous earth and washed with methanol (2 x 5 mL). The filtrate was concentrated under reduced pressure to give the crude product. The crude product was ground with a solvent mixture of dichloromethane and ethyl acetate (1:1, 2 mL), followed by the addition of an ether solution of 1N hydrochloric acid (4 mL) to give 2-cyclohexylethylamine hydrochloride (261, 250 mg, 38%) as a white solid.TLC conditions: 20% ethyl acetate/hexane (Rf 0.3); 1H-NMR (DMSO-d6, 500 MHz): δ 7.79 (broad single peak, 2H), 2.77 (triple peak, J = 7.5 Hz, 2H), 1.66-1.59 (multiple peak, 5H), 1.45-1.41 (multiple peak, 2H), 1.32-1.28 (multiple peak, 1H), 1.23-1.11 (multiple peak, 3H), 0.91-0.84 (multiple peak, 2H).
