A solution of aluminum trichloride (0.266 g, 2.00 mmol) in 1:1 DCM:CH3NO2 (5 mL) was added slowly to a slurry of 2,6-difluoro-3-(propylsulfonamido)-N-(1H-pyrrolo[2,3-b]pyridin-5-yl)benzamide (0.100 g, 0.254 mmol) in 1:1 DCM:CH3NO2 (2 mL) at 0° C. The solution was stirred at 0° C. for 40 minutes. A solution of 2-chloroacetyl chloride (0.0307 mL, 0.380 mmol) in DCM (1 mL) was added, and the reaction mixture was allowed to warm to room temperature overnight. Additional 2-chloroacetyl chloride (5 eq.) was added, and the reaction mixture was warmed to 50° C. for 20 hours. The solution was cooled and diluted with saturated aqueous ammonium chloride and extracted with EtOAc (3 X). The organic layers were dried over Na2SO4, filtered and concentrated under reduced pressure. They were then purified via column chromatography (5% MeOH/DCM) to afford N-(3-(2-chloroacetyl)-1H-pyrrolo[2,3-b]pyridin-5-yl)-2,6-difluoro-3-(propylsulfonamido)benzamide (59 mg, 50%) as a solid.
