To a solution of 4-[{N-(3-(trifluoromethyl)benzoyl)glycyl}aminomethyl]piperidine (20.0 mg, 0.058 mmol) and 3-hydroxy-4-methoxybenzaldehyde (33 mg) in 5% CH3COOH/CH3OH (1.0 mL) was added NaBH3CN (16.5 mg) in 5% CH3COOH/CH3OH (1.0 mL). The reaction mixture was stirred at 60° C. for 15 h. The reaction mixture was loaded onto Variant™ SCX column and washed with CH3OH (15 mL). Product was eluted using 2 N NH3-CH3OH (5 mL) and the eluant was concentrated to afford 1-(3-hydroxy-4-methoxybenzyl)-4-[{N-(3-(trifluoromethyl)benzoyl)glycyl}aminomethyl]piperidine (Compound No. 1452) (25.8 mg, 92%): The purity was determined by RPLC/MS (91%); ESI/MSm/e 480 (M++H, C24H28F3N3O4).
