1198416-32-8

348640-02-8

1198416-32-8

1-Toluenesulfonyl-1H-pyrrolo[2,3-b]pyridine (50.0 g, 183.8 mmol) was used as starting material, which was dissolved in anhydrous THF and cooled to -78 °C. n-Butyllithium (81 ml, 2.5 M hexane solution) was added slowly over 20 min. After the reaction mixture was kept at -78 °C for 1 h, anhydrous THF solution of carbon tetrabromide (71.0 g, 220.5 mmol) was added. Stirring was continued at -78 °C for 30 min, followed by slow warming to room temperature. Upon completion of the reaction, the solvent was removed by distillation under reduced pressure. The residue was separated by extraction with ethyl acetate and water and the organic layer was dried over anhydrous sodium sulfate and concentrated. The crude product was purified by column chromatography with a gradient elution of petroleum ether solution with an eluent ranging from 5% to 20% ethyl acetate to afford 2-bromo-1-toluenesulfonyl-1H-pyrrolo[2,3-b]pyridine (37 g, 58% yield). Mass spectrometry analysis (MS-ESI): m/z = 351.0 [M + 1]+.