6-BROMO-3H-IMIDAZO[4,5-B]PYRIDINE

Application

Literature reports that 6-bromo-3H-imidazo[4,5-B]pyridine can be used to prepare inhibitors targeting the PI3K-AKT-mTOR signaling pathway, such as 2-[4-[8-(3H)imidazo[4,5-b]pyridin-6-yl)-3-methyl-1H-pyrazole[4,3-c]quinoline-1-yl]phenyl]-2-methylpropionitrile.

Synthesis

The reaction was carried out with 2,3-diamino-5-bromopyridine (1.00 g, 5.32 mmol) and formic acid (0.5 mL) in 15 mL of triethyl orthoformate with stirring for 3 h at 100 °C. The reaction was carried out by LC-MS. The reaction progress was monitored by LC-MS, and after confirming the completion of the reaction, the reaction mixture was concentrated under reduced pressure. The crude product was purified by column chromatography (eluent: 10% methanol/dichloromethane) to afford 6-bromo-4H-imidazo[4,5-B]pyridine (1.01 g, 96% yield) as a beige solid.1H NMR (400 MHz, DMSO-d6) δ 8.46 (s, 1H), 8.41 (d, 1H), 8.27 (d, 1H).

References

[1] Patent: WO2008/82487, 2008, A2. Location in patent: Page/Page column 107
[2] Patent: WO2016/142310, 2016, A1. Location in patent: Page/Page column 86-87
[3] Patent: EP2766359, 2016, B1. Location in patent: Paragraph 0737
[4] Patent: WO2009/42607, 2009, A1. Location in patent: Page/Page column 72
[5] Patent: WO2007/127183, 2007, A1. Location in patent: Page/Page column 140-141