According to Example 132, by use of 2-chloro-3-[2,2,2-trifluoro-1-(pyridin-3-yl)ethoxy]-quinoxaline (Compound BJ) (70 mg, 0.21 mmol), dimethyl sulfoxide (2 mL), 2-cyanobenzenesulfonamide (38 mg, 0.21 mmol) and potassium carbonate (28 mg, 0.21 mmol), the mixture was stirred and reacted at 150° C. for 1.5 hours. The reaction mixture was allowed to cool down to room temperature, a 1% aqueous acetic acid solution was added thereto, and extraction with ethyl acetate was performed. The organic layer was washed with a saturated aqueous sodium chloride solution and dried over anhydrous magnesium sulfate, and then the solvent was evaporated off under reduced pressure. The residue was subjected to slurry purification using methanol, to give 2-cyano-N-{3-[2,2,2-trifluoro-1-(pyridin-3-yl)ethoxy]-quinoxalin-2-yl}benzenesulfonamide (Compound 145) (70 mg, 70%).
