Platinum(IV) oxide (1.45 g, 6.4 mmol) was added to a mixed solution of 4-pyridinepropanol (10.0 g, 72.89 mmol) in methanol (110 mL) and 32% hydrochloric acid (18 mL) under argon protection. The reaction mixture was stirred vigorously under low pressure hydrogen (8 kPa) for 46 hours. Upon completion of the reaction, most of the catalyst was removed by filtration, followed by distillation under reduced pressure to remove the volatile solvent. The oily residue obtained was dissolved in 15% NaOH aqueous solution (80 mL) and extracted with dichloromethane (first 150 mL, then 3 x 100 mL). The organic phases were combined, washed with deionized water (20 mL) and dried over anhydrous sodium sulfate. The organic phase was concentrated under reduced pressure and dried under vacuum to give 3-(4-piperidinyl)-1-propanol (10.3 g, 98% yield) as a white crystalline solid with a melting point of 58-60 °C. Thin layer chromatography (TLC) showed Rf = 0.2 (Expander: dichloromethane/methanol/28% ammonia = 50:10:1). Infrared spectroscopy (Nujol) showed characteristic absorption peaks located at 3290 cm?1 and 1320 cm?1. NMR hydrogen spectra (300 MHz, CD?OD) δ (ppm): 1.08-1.23 (m, 2H), 1.27-1.36 (m, 2H), 1.36-1.49 (m, 1H), 1.53-1.63 (m, 2H). 1.74 (br d, 2H, J≈13.4 Hz), 2.59 (dt, 2H, J=12.4, 2.6 Hz), 3.04 (td, 2H, J=12.4, 2.9 Hz), 3.56 (t, 2H, J=6.6 Hz). NMR carbon spectrum (75 MHz, CD?OD) δ (ppm): 31.5, 34.8, 35.2, 38.0, 47.9, 64.0. mass spectrum (ESI, MeOH) m/z (%): 287 (36) [2M+H]? , 144 (100) [M+H]? Molecular formula C?H??NO (molecular weight 143.2).
