A (piperidinomethyl)polystyrene resin (28 mg, 2.8 mmol/g) and 3-(trifluoromethyl)phenyl isocyanate (1.3 equivalents) were added to a chloroform (2 mL) solution of 1-(4-chlorobenzyl)-4-[(glycylamino)methyl]piperidine (14.8 mg, 0.05 mmol). The resulting mixture was stirred at 25° C. for 16 hours, and an (aminomethyl)polystyrene resin was added to the obtained mixture. The resulting mixture was stirred at 25° C. for 16 hours to trap the remaining isocyanate. The obtained mixture was filtered and concentrated to thereby provide 1-(4-chlorobenzyl)-4-[[2-(3-(4-trifluoromethylphenyl)ureido) acetylamino]methyl]piperidine (Comp d. No. 852) (19 mg, 78%). The purity was determined by RPLC/MS (92%). ESI/MS m/e 483 (M++H, C23H26ClF3N4O2).
