To a reaction vessel under argon containing 2-(6-bromo-5-methylpyridin-2-yl)isoindoline-1,3-dione (85 mg, 0.27 mmol), 2-(tributylstannyl)pyridine (123 mg, 0.32 mmol), Pd(PPh3)4(31 mg, 0.027 mmol) is added anhydrous toluene (0.7 ml). The mixture is heated to 116° C. with an oil bath for 18 hours, cooled to room temperature, diluted with ethyl acetate and filtered through a celite pad to remove any solids. The filtrate is concentrated to afford 2-(3-methyl-2,2′-bipyridin-6-yl)isoindoline-1,3-dione as a brown solid (LC-MS m/z: 316.1 (M+1)) which is used without further purification in the next step.
