2-Chloro-4′-fluoro-5-iodobiphenyl-4-ol (Preparation 72, 553 mg, 1.59 mmol) and 4-(tributylstannyl)pyridazine (703 mg, 1.90 mmol) were dissolved in degassed acetonitrile (8 mL). Caesium fluoride (482 mg, 3.17 mmol) was added and the mixture further degassed. Tetrakistriphenylphosphinepalladium (0) (183 mg, 0.16 mmol) and copper (I) iodide (91 mg, 0.48 mmol) were added and the reaction heated at 50° C. for 2 hours. The reaction mixture was cooled and filtered through celite, washing with ethyl acetate. The organic solution was washed with water and brine, dried over MgSO4, filtered and concentrated in vacuo. The residue was purified by trituration with hot ethyl acetate to give the title compound (151 mg, 32%) as a beige solid.
