To a solution of 5-(4-fluorophenyl)-4-(4-pyridinyl)-1H-pyrazole-3-carboxylic acid, monohydrate prepared in accordance with Example A-200 (0.9905 g, 3.5 mmol) and 1-hydroxybenzotriazole (0.4824 g, 3.57 mmol) in DMF (20 ml) at 0° C. under nitrogen, 1-(3-dimethylaminopropyl)3-ethylcarbodiiminde hydrochloride (0.6984 g, 3.57 mmol, Aldrich Chemical Co.) was added. The solution was stirred at 0° C. under nitrogen for 1 hour then 1-butoxycarbonylpiperazine (0.6585 g, 3.5 mmol) was added followed by N-methylmorpholine (0.40 ml, 3.6 mmol). The reaction was stirred from 0° C. to room temperature overnight. After 19 hours, the solvent was removed under reduced pressure, and resulting residue was diluted with ethyl acetate, washed with saturated NaHCO3 solution, water and brine, and dried over MgSO4. After filtration, the solvent was removed under reduced pressure to give a crude product (1.7595 g). 1,1-Dimethylethyl 4-[[5-(4-fluorophenyl)-4-(4-pyridinyl)-1H-pyrazol-3-yl]carbonyl]-1-piperazinecarboxylate (1.2372 g, 78.4%) was obtained by chromatography. Anal. Calc'd for C24H2N5O3F. (451): C, 63.85; H, 5.80; N, 15.51; Found: C, 63.75; H, 5.71; N, 15.16. MS (MH+): 452 (base peak).
