To 3-(4-Pyridin-4-yl-1H-pyrazol-3-yl)-phenylamine (700 mg, 3 mmol) in anhydrous pyridine (15 mL) at 0° C. 4-trifluoromethylphenylisocyanate (420 μL, 3 mmol) was added. The reaction was stirred for 2 hours at 0° C. under nitrogen atmosphere to give a mixture of monourea and bis-urea as regioisomeric mixture. Solvent was removed under reduced pressure. The residue was dissolved in methanol (15 mL) and triethylamine (1 mL, 7.8 mmol) was added and the reaction was stirred at room temperature overnight. After this time only the monourea could be detected by HPLC/MS. The solvent was removed under reduced pressure and the residue was dissolved in ethyl acetate (100 mL) and washed successively with water (3×50 mL). The crude was purified by silica gel column chromatography (DCM/methanol 9:1) to give the desired product as a white solid (75%).
