Reaction Steps
A solution of 1-methyl-4-(4-nitrophenoxymethyl)piperidine (24) (1.0 g, 4.0 mmol), MeOH (20 mL), and concentrated HCl (1 mL) was hydrogenated over Pd/C (10%, 100 mg) at 58 psi H2 for 1 h at room temperature. Then, the solid was removed by filtration through Celite, which was washed thoroughly with MeOH (200 mL), and the filtrate was concentrated in vacuo. The residue was dissolved in water (50 mL) and the resulting solution was adjusted to pH 10 with a saturated aqueous solution of NaHCO3 and 2 M NaOH. The mixture was extracted with CH2Cl2 (3×100 mL), dried (MgSO4), and the solvent was removed in vacuo. Purification by column chromatography (CH2Cl2/MeOH, 10:1, 2% NEt3) gave 25 (0.72 g, 82%) as a reddish brown solid. 1H NMR (300 MHz, CDCl3): δ=1.31-1.48 (m, 2 H, 3′-Hax, 5′-Hax), 1.66-1.89 (m, 3 H, 3′-Heq, 4′-H, 5′-Heq), 1.96 (dt, J=11.9, 2.3 Hz, 2 H, 2′-Hax, 6′-Hax), 2.28 (s, 3 H, NMe), 2.84-2.93 (m, 2 H, 2′-Heq, 6′-Heq), 3.41 (sbr, 2 H, NH2), 3.73 (d, J=6.4 Hz, 2 H, OCH2), 6.60-6.67 (m, 2 H, 3-H, 5-H), 6.70-6.76 (m, 2 H, 2-H, 6-H) ppm. —13C NMR (75.5 MHz, CDCl3): δ=29.1 (C-3′, C-5′), 35.3 (C-4′), 46.4 (NMe), 55.4 (C-2′, C-6′), 73.2 (OCH2), 115.4 (C-3, C-5), 116.3 (C-2, C-6), 139.8 (C-1), 152.2 (C-4) ppm. −MS (70 eV, EI): m/z (%)=220 (3) [M]+, 112 (100) [C7H14N]+. —C13H20N2O (220.31): calcd. C, 70.87; H, 9.15; found C, 70.50; H, 8.94.
