Step 2: Preparation of 3-amino-1-benzylpiperidine
2.13 g of 3-(N-acetylamino)-1-benzylpiperidine was dissolved in 10 mL of 6 N hydrochloric acid and the reaction was stirred under reflux conditions for 1 hr. After completion of the reaction, the mixture was cooled to room temperature and the pH was adjusted to 9-10 by slow addition of 6 N aqueous ammonia solution.Subsequently, the mixture was extracted four times with chloroform (15 mL each time), the organic phases were combined and dried over anhydrous sodium sulfate. The dried organic phase was concentrated under reduced pressure to give 1.21 g of 3-amino-1-benzylpiperidine in 96.3% yield. The product was characterized by 1H NMR (CDCl3): δ 7.31 (m, 5H), 3.51 (s, 2H), 2.93-2.61 (m, 3H), 2.06 (t, 1H), 1.90-1.52 (m, 4H), 1.20-1.02 (m, 1H) ppm.