A solution of 1-(4-chlorobenzyl)-4-{(glycylamino)methyl}piperidine (14.8 mg, 0.05 mmol) in CHCl3 (2 mL) was treated with (piperidinomethyl)polystyrene resin (28 mg, 2.8 mmol/g), 3-(trifluoromethyl)phenyl isocyanate (1.3 equiv.) and stirred at 25° C. for 16 h. (Aminomethyl)polystyrene was added to scavenge the residual isocyanate and the reaction mixture was stirred at 25° C. for 16 h. Filtration and concentration afforded 1-(4-chlorobenzyl)-4-[{2-(3-(4-trifluoromethylphenyl)ureido)acetylamino}methyl]piperidine (19 mg, 78%) (compound No. 852): The purity was determined by RPLC/MS (92%); ESI/MS m/e 483 (M++H, C23H26ClF3N4O2)
