To a stirred solution of tert-butyl 2-(2-((3-(methylsulfonamido) phenyl)amino)oxazol-5-yl)-1H-indole-1-carboxylate 24 (0.221 g, 0.472 mmol) in methanol (30 mL) was added potassium carbonate (0.652 g, 4.71 mmol) at room temperature. Reaction mixture was refluxed for 2 hours. After completion of the reaction (as judged by TLC) it was concentrated using rotavapour and the crude product was purified by MPLC column chromatography (Biotage; Acetone/hexane as an eluent) to provide N-(3-((5-(1H-indol-2-yl)oxazol-2-yl)amino)phenyl)methanesulfonamide 25 (0.11 g, 63% yield) as a solid. MS (ES) m/z 369 (M+H+).
