A mixture of 0.90 g (2.89 mmol) of 2-(4-fluorophenyl)-6-(4-methylpiperazin-1-yl)imidazo[1,2-b]pyridazine (Synthesis, 2001, 4, 595-600), 0.71 g (3.5 mmol) of 4-iodopyridine, 0.032 g (0.14 mmol) of palladium acetate and 0.48 g (3.5 mmol) of potassium carbonate in 18 mL of dimethylformamide is heated at 135° C. for 18 hours. After cooling, the reaction medium is poured into water and the product is extracted with ethyl acetate. The organic phase is washed with water and dried over sodium sulfate, and the solvent is evaporated off under reduced pressure. The residue is purified on a column of silica gel, eluting with a mixture of dichloromethane, methanol and aqueous ammonia (95/5/0.5) to give 0.5 g of crystals after recrystallization from acetonitrile, filtering off and drying under reduced pressure.
