5-BROMO-2,3-DIHYDRO-1H-PYRROLO[2,3-B]PYRIDINE

10592-27-5

115170-40-6

a) 16.8 g (0.14 mol) of 2,3-dihydro-1H-pyrrolo[2,3-b]pyridine, 24.13 g (0.143 mol) of 48% hydrobromic acid and 260 g of methylene chloride were added to a reaction flask and stirred thoroughly to obtain reaction mixture C; b) The temperature of reaction mixture C was controlled at 25~30°C, and 20.20 g of 20% hydrogen peroxide solution was added slowly dropwise. hydrogen peroxide solution to obtain mixture D; c) Neutralize mixture D using 60 g of saturated aqueous sodium bisulfite solution until the red color of the reaction solution completely disappeared, and carry out partitioning to obtain the organic phase E and the aqueous phase F; d) Wash the organic phase E with 200 g of water; e) Recover the dichloromethane solvent from the organic phase E obtained in step d) to obtain 26.6 g of 5-bromo-2,3-dihydro-1H-pyrrolo[ 2,3-b]pyridine in 95.6% yield and the product was ≥99% pure by liquid chromatography.