To 200 mg (0.71 mM) of 2-bromo-4-(cyclopropylmethyl)pyrido[2,3-b]pyrazin-3(4H)-one and 25.3 mg (0.036 mM) of bis(triphenylphosphine) palladium(II)chloride in 1 ml of dimethylformamide were added 142.9 mg (0.93 mM) of (4-fluoro-2-methylphenyl)boronic acid, 0.1 ml of ethanol and 715 μl of a 2M aqueous solution of sodium carbonate. The reaction mixture was then refluxed for 20 h under stirring. Water and ethyle acetate were added. The organic layer was separated, washed with water, dried on anhydrous sodium sulfate and the solvent was removed under vacuum. The compound was further purified by silica gel column chromatography, using dichloromethane as eluant, to give, after evaporation, 100 mg of 4-(cyclopropylmethyl)-2-(4-fluoro-2-methylphenyl)pyrido[2,3-b]pyrazin-3(4H)-one as a white solid. (Yield: 45.3%)
