14.5 mg of pyrazine-2-carboxylic acid and 27.0 mg of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide monohydrochloride were added in order to a pyridine (1 ml) solution of 53 mg of 1-(2-(4,5-diamino-2-(4-methanesulfonyl-phenoxy)-phenyl)-pyrrolidin-1-yl)-2,2,2-trifluoro-ethanone obtained in Example 162 (step 6), and the reaction liquid was stirred at room temperature for 3 hours. The reaction liquid was diluted with saturated saline, and extracted with ethyl acetate. The organic layers were combined, washed with aqueous saturated ammonium chloride and aqueous saturated sodium bicarbonate in order, and dried with anhydrous magnesium sulfate. The solvent was evaporated away under reduced pressure, and the resulting residue was dissolved in 1 ml of toluene. 9.9 mg of p-toluenesulfonic acid monohydrate was added to it, and the reaction liquid was stirred at 120° C. for 6 hours. After cooled, the reaction liquid was diluted with ethyl acetate, washed with aqueous saturated sodium bicarbonate and saturated saline in order, and dried with anhydrous magnesium sulfate. The solvent was evaporated away under reduced pressure, and the residue was purified through partitioning thin-layer chromatography (Kieselgel™ 60F254, Art 5744 (by Merck), chloroform/methanol=9/1) to obtain the entitled compound as an oily substance.
