To a solution of 4-(tributylstannyl)pyridazine (1.71 g, 4.64 mmol) and 3-iodo-3′-(trifluoromethyl)biphenyl-4-ol (Preparation 2, 1.30 g, 3.57 mmol) in N,N-dimethylformamide (20 mL) was added caesium fluoride (1.10 g, 7.14 mmol). The mixture was degassed before the addition of tetrakis(triphenylphosphine) palladium (0) (412 mg, 0.357 mmol), then heated to 45° C. for 4 hours. The reaction was concentrated in vacuo and purified by silica gel column chromatography (0%-20% methanol in dichloromethane gradient elution). The residue was triturated with acetonitrile and filtered to afford the title compound (420 mg, 37%) as a solid.
