5-(4-Chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxylic acid (1 eq., 201 mg, 0.53 mmol), triethylamine (3 eq, 0.22 mL, 0.157 mmol), tert-butyl N-(4-phenyl piperidin-4-yl)carbamate (1 eq, 146 mg, 0.53 mmol), and Benzotriazole-1-yl-oxytris(dimethylamino)phosphonium hexafluorophosphate (BOP) (1 eq, 233 mg, 0.53 mmol) was stirred in tetrahydrofuran (10 mL) for 16 h. The reaction was concentrated in vacuo. The crude reaction material was then purified by silica gel column chromatography using 0-100% ethyl acetate/hexane to yield pure tert-butyl N-(1-{[5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazol-3-yl]carbonyl}-4-phenylpiperidin-4-yl)carbamate (295 mg, 87%). 1H NMR (300 MHz, CHLOROFORM-d) d ppm 1.37 (br. s., 9H) 2.11 (dd, J=12.67, 4.00 Hz, 2H) 2.21 (s, 3H) 2.24-2.34 (m, 1H) 2.34-2.56 (m, 1H) 3.26 (t, J=12.01 Hz, 1H) 3.56 (t, J=12.39 Hz, 1H) 4.32 (d, J=13.75 Hz, 1H) 4.64 (d, J=13.56 Hz, 1H) 4.96 (br. s., 1H) 7.08 (d, J=8.38 Hz, 2H) 7.13-7.49 (m, 10H).
