General Procedure for Boc Deprotection (General Procedure B)

The corresponding boc-protected piperidine was dissolved in 2 N HCl in MeOH (30 mL) and was heated to 60 °C for 2 h. The excess MeOH was removed by a rotary evaporator and diluted with H₂O (30 mL), and the solution was treated with NaOH pellets to reach pH = 11. The product was extracted with EtOAc, dried over NaSO₄, and evaporated to afford the product.