2-Iodo-4-(6-(trifluoromethyl)pyridin-3-yl)phenol (Preparation 60, 840 mg, 2.30 mmol) was dissolved in acetonitrile (20 mL) and 4-(tributylstannyl)pyridazine (1.10 g, 2.99 mmol), caesium fluoride (698 mg, 4.60 mmol), copper iodide (87 mg, 0.46 mmol) and tetrakis(triphenylphosphine)palladium (0) (266 mg, 0.23 mmol) were added. The reaction mixture was stirred at 80° C. for 18 hours and then partitioned between ethyl acetate and water containing 0.88 ammonia. The resulting mixture was stirred for 15 minutes and then filtered through a pad of celite. The aqueous phase was separated and extracted with ethyl acetate (2×20 mL) and the combined organic phases were washed with brine, dried over anhydrous MgSO4, filtered and concentrated in vacuo. The residue was purified on silica gel by Biotage (10% to 100% EtOAc in heptane over 25 CV) to give a mixture of the title compound and triphenylphosphine oxide. The residue was triturated with dichloromethane to give the title compound (360 mg, 50%) as a white solid.
