98-59-9

348640-06-2

348640-07-3

4-Bromo-7-azaindole (3 g, 15.22 mmol) was used as starting material and dissolved in tetrahydrofuran (THF, 50 mL) under nitrogen protection in a round bottom flask. The reaction mixture was cooled to 0 °C and sodium hydride (60% dispersed in mineral oil, 0.67 g, 16.75 mmol) was added in batches, and the outgassing phenomenon was observed during the addition. After the addition, the reaction mixture was stirred at room temperature for 30 min. Subsequently, p-toluenesulfonyl chloride (2.14 mL, 16.75 mmol) was slowly added to the reaction system. The reaction mixture was gradually warmed up to room temperature and stirring was continued for 2 hours. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure and the residue was dissolved with dichloromethane (DCM, 30 mL). The organic phase was washed with 2 M sodium carbonate solution (2 x 30 mL), dried over anhydrous magnesium sulfate (MgSO4), filtered and concentrated to give an orange colored oil. Purification was carried out by fast column chromatography with the eluent ethyl acetate:cyclohexane (1:9, v/v) to afford the target compound 4-bromo-1-[(4-methylphenyl)sulfonyl]-1H-pyrrolo[2,3-B]pyridine as an off-white solid in 92% yield. The product was analyzed by LCMS (Method 5, retention time 5.36 min, molecular ion peak m/z 337 [M + H]+) and 1H NMR (500 MHz, CDCl3) to confirm the structure: δ 8.22 (d, 1H), 8.18 (d, 2H), 7.78 (d, 1H), 7.58 (t, 1H), 7.48 (t, 2H), 7.35 (d , 1H), 6.63 (d, 1H).