To a solution of tris(dibenzylideneacetone)dipalladium(0) (1.14 g) and 4,5′-bis(diphenylphosphino)-9,9′-dimethylxanthene (1.45 g) in 1,4-dioxane (150 mL), ethyl 2-amino-4-(propylamino)pyrimidine-5-carboxylate (C3, 5.61 g), 4-bromobenzonitrile (6.83 g) and cesium carbonate (24.40 g) were added at room temperature, and the mixture was stirred at 100° C. for 11 hours and 30 minutes under a nitrogen atmosphere. The reaction mixture was cooled to room temperature, then the insoluble matter was removed by filtration through Cerite, and then 1.0 mol/L aqueous hydrochloric acid and ethyl acetate were added. The organic layer was separated, washed successively with 1.0 mol/L aqueous hydrochloric acid, saturated aqueous sodium hydrogencarbonate and saturated aqueous sodium chloride, and then dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. To the obtained residue, ethyl acetate was added, and the solid matter was taken by filtration to obtain ethyl 2-((4-cyanophenyl)amino)-4-(propylamino)pyrimidine-5-carboxylate (C4, 2.68 g).
