7.0 mg of 5-bromo-2-cyano-pyrimidine and 15 mg of cesium carbonate were added to an N-methylpyrrolidinone (0.5 ml) solution of 7.0 mg of 5-(2-fluorophenoxy)-6-hydroxy-2-pyrazin-2-yl-1H-benzimidazole obtained in the step 1, and the reaction liquid was stirred at 90° C. for 15 minutes. The reaction mixture was purified through reversed-phase middle-pressure liquid chromatography [ODS-AS-360-CC (by YMC), mobile phase: water-acetonitrile-0.1% trifluoroacetic acid]. The resulting fraction was diluted with ethyl acetate, washed with aqueous saturated sodium bicarbonate, and dried with anhydrous sodium sulfate. The solvent was evaporated away under reduced pressure to obtain the entitled compound a colorless solid.
