A mixture of 3-bromo-1-[3-(trifluoromethyl)phenyl]pyridazin-4(1H)-one (319 mg, 1.0 mmol), (3-phenyl-1-trityl-1H-pyrazol-4-yl)boronic acid (645 mg, 1.5 mmol), Pd(PPh3)4 (58 mg, 0.05 mmol), Na2CO3 (318 mg, 3.0 mmol), DME (7.5 mL), and H2O (1.5 mL) was refluxed overnight under Ar atmosphere. After cooling to room temperature, the reaction mixture was poured into water and extracted with AcOEt. The extract was washed with brine, dried over MgSO4, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography eluting with hexane/AcOEt (1/1) and crystallized from MeOH to give the title compound (418 mg, 67% yield) as a white solid:
