A solution of 5-(2,6-difluorophenyl)-3-iodo-1H-pyrrolo[3,2-b]pyridine (657 mg, 1.845 mmol) in THF (18 mL) was treated with 4-toluenesulfonyl chloride (387 mg, 2.029 mmol, Aldrich) and solid NaOH (89 mg, 2.214 mmol, VWR). The reaction was stirred at 23° C. under N2. After 45 min, the solution was diluted with EtOAc (200 ml) and washed with brine (150 mL), dried over MgSO4, concentrated in vacuo and purified by silica gel chromatography (eluent: 10-30% EtOAc/hexane), affording 5-(2,6-difluorophenyl)-3-iodo-1-tosyl-1H-pyrrolo[3,2-b]pyridine.
