4-Phenyl-1,2,3,4-tetrahydropyridine--hydrogen chloride (1/1) → 4-Phenylpiperidine

Participants

Reaction Steps

A mixture of 20.5 g (104.9 mmol) of 4-phenyltetrahydropyridine hydrochloride (Aldrich) and 0.5 g of 10% Pd/C in 40 mL of H2O and 160 mL of EtOH was stirred under hydrogen at 45 psi for 2 h. The reaction mixture was then filtered though a thin pad of celite eluting with EtOH and H2O. The filtrate was concentrated and the residue was stirred in 75 mL of ether. To it at 0° C. was added 5 g of solid NaOH. The layers were separated and the aqueous layer was extracted with ether. The combined organic fractions were washed with sat'd NaCl solution, dried over Na2SO4, filtered and the filtrate was concentrated. The residue was crystalized from cold heptane to give 10 g of the title compound. 1H NMR (CDCl3) δ7.33 (t, 2H, J=7.7 Hz), 7.25-7.28 (m, 3H), 6.90 (bs, 1H), 3.65 (d, 2H, J=12.6 Hz), 3.04 (d of d,2H, J=13.0, 2.5 hz), 2.78 (t of d, 1H, J=12.1, 3.2 Hz), 2.21-2.30 (m,2H), 2.05 (d, 2H, J=14.0 Hz).

Provenance & Evidence