A solution of 6-piperazin-1-yl-2-(2-trifluoromethylphenylamino)-1H-benzimidazole-5-carboxylic acid (1H-indazol-6-yl)-amide trihydrochloride (0.3 mmol; see Example 88) in DMF (1 mL) was added with triethylamine (1.5 mmol) and N,N-dimethylsulfamoyl chloride (0.4 mmol). The resulting mixture was stirred at RT for 4 h and added with hydrazine hydrate (2 mmol). The contents were warmed to 50° C. and stirred vigorously for 60 min. The reaction mixture was then poured into ice cold water, and the solid was filtered, washed with water, and dried under vacuum. The crude product was then purified on a silica gel column chromatography using MeOH/DCM as eluent to afford 6-(4-dimethylsulfamoyl-piperazin-1-yl)-2-(2-trifluoromethylphenylamino)-1H-benzoimidazole-5-carboxylic acid (1H-indazol-6-yl)-amide as a white solid. MS: m/z 628 (M+H)+.
