[CH2:1]([N:8]1[CH2:13][CH:12]=[C:11]([C:14]2[CH:19]=[CH:18][C:17]([O:20][CH3:21])=[CH:16][CH:15]=2)[CH2:10][CH2:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.[H][H].Cl>[Pd].CO.Cl>[CH2:1]([N:8]1[CH2:9][CH2:10][CH:11]([C:14]2[CH:15]=[CH:16][C:17]([O:20][CH3:21])=[CH:18][CH:19]=2)[CH2:12][CH2:13]1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1Palladium on carbon (10%, 0.0695 g) is added to a mixture of 1-benzyl-1,2,3,6-tetrahydro-4-(4-methoxyphenyl)pyridine (XVI, Step 2, 0.6843 g, 2.4 mmol) in methanol/hydrochloric acid and the mixture is shaken overnight under approximately 40 psi of hydrogen. Additional palladium on carbon and concentrated hydrochloric acid are added and the mixture is again shaken overnight under hydrogen. The palladium on carbon then is filtered off and the filtrate is concentrated. The residue is partitioned between dichloromethane and saturated sodium bicarbonate and the combined organic phases are backwashed with saturated sodium bicarbonate, dried over magnesium sulfate, and concentrated to give 1-benzyl-4-(4-methoxyphenyl)piperidine (XVIII), NMR (CDCl3) 1.77, 2.07, 2.45, 3.00, 3.55, 3.78, 6.85, 7.16 and 7.31 δ.
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