5-Bromo-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine

Uses

5-Bromo-2,3-dihydro-1H-pyrrolo[2,3-b]pyridine is a useful intermediate for organic synthesis.

Synthesis

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.

References

[1] Patent: CN107987076, 2018, A. Location in patent: Paragraph 0048-0053; 0064-0069; 0074; 0080-0085
[2] Patent: CN105461718, 2016, A. Location in patent: Paragraph 0016
[3] Patent: WO2004/78757, 2004, A2. Location in patent: Page 48; 50-51
[4] Patent: WO2015/157504, 2015, A1. Location in patent: Page/Page column 37
[5] Patent: EP1782811, 2007, A1. Location in patent: Page/Page column 63