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

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).

1. filtrationThe reaction mixture was then filtered though a thin pad of celite
2. washeluting with EtOH and H2O
3. concentrationThe filtrate was concentrated
4. stirringthe residue was stirred in 75 mL of ether
5. additionTo it at 0° C. was added 5 g of solid NaOH
6. customThe layers were separated
7. extractionthe aqueous layer was extracted with ether
8. washThe combined organic fractions were washed with sat'd NaCl solution
9. dry with materialdried over Na2SO4
10. filtrationfiltered
11. concentrationthe filtrate was concentrated
12. customThe residue was crystalized from cold heptane

ORD record

ord-79764fbe273149d0984164fe30601166

Source dataset

uspto-grants-2001_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06303593B1