Under an argon atmosphere, 140 mg (purity 65%, 0.256 mmol) of 6-chloro-3-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridin-3-yl]-1,2,4-triazine-5-amine were suspended in 5 ml of absolute dioxane. 117 mg (0.767 mmol) of (6-methoxypyridin-3-yl)boronic acid, 1.023 ml (1.023 mmol) of 1N aqueous potassium carbonate solution and 14 mg (0.051 mmol) of tricyclohexylphosphine were added and argon was passed through the suspension for 10 min with stirring. Then, 28 mg (0.038 mmol) of 1,1′-bis(diphenylphosphino)ferrocenepalladium(II) chloride were added and the reaction mixture was stirred for 30 min in the microwave at 140° C. After cooling, the mixture was filtered over an Extrelut cartridge and after-washed with a mixture of dichloromethane/methanol (v/v=20:1). The filtrate was concentrated and the residue was purified by preparative HPLC (mobile phase: acetonitrile/water, gradient 20:80→100:0). This gave 58 mg of the target compound (purity 85%; 36% of theory).
