918504-27-5

1103234-56-5

183208-35-7

918504-27-5

General method: 2,6-Difluoro-3-(propylsulfonamido)benzoic acid (1.1 eq.) was suspended in anhydrous dichloromethane (DCM, 0.5 M), oxalyl chloride (1.05 eq.) and a catalytic amount of N,N-dimethylformamide (DMF, a few drops) were added sequentially. The reaction mixture was stirred at room temperature until gas release ceased. Subsequently, the resulting chloride solution was slowly added dropwise to a suspension of anhydrous DCM (0.5 M) containing 5-bromo-7-azaindole (1 eq.) and anhydrous aluminum trichloride (AlCl3, 5 eq.). The reaction mixture was continued to be stirred at room temperature for 0.5 to 3 hours. Upon completion of the reaction, saturated aqueous ammonium chloride (NH4Cl) was added to quench the reaction. The aqueous phase was extracted with ethyl acetate (EtOAc, 3 times) and the combined organic layers were dried over anhydrous sodium sulfate (Na2SO4) and concentrated under reduced pressure to remove the solvent. The crude product was purified by fast column chromatography using silica gel (SiO2) as stationary phase and n-hexane/ethyl acetate (1:1, v/v) or dichloromethane/methanol (the methanol content was increased in a gradient from 0.5% to 5%, and ultimately did not exceed 3%, v/v) to afford the target compound N-[3-[(5-bromo-1H-pyrrolo[2,3-b]pyridin-3-yl) carbonyl]-2,4-difluorophenyl]-1-propanesulfonamide.