68618-36-0

Light yellow solid

1H-PYRAZOLO[3,4-B]PYRIDINE, 3-BROMO- is a pyrimidine derivative that acts as a stimulant. It has been shown to cause pulmonary hypertension in rats and has been used to induce pulmonary hypertension in rats. This drug has also been shown to have an effect on the rat heart and is being researched for its biological profiles.

The general procedure for the synthesis of 3-bromo-1H-pyrazolo[3,4-b]pyridine using 1H-pyrazolo[3,4-b]pyridine as starting material was as follows: bromine (1.91 mL, 37.1 mmol) was slowly added dropwise to a solution of 1H-pyrazolo[3,4-b]pyridine (2.6 g, 21.8 mmol) dissolved in chloroform (100 mL). The reaction mixture was stirred overnight at room temperature. Upon completion of the reaction, the mixture was concentrated to remove the solvent. The concentrated residue was dissolved in a mixture of ethyl acetate (200 mL) and saturated sodium bicarbonate solution (50 mL). The aqueous layer was extracted twice with ethyl acetate (50 mL). All organic layers were combined, dried over anhydrous sodium sulfate, filtered to remove the desiccant, and the filtrate was subsequently concentrated to afford 3-bromo-1H-pyrazolo[3,4-b]pyridine (3.7 g, 86% yield) as a solid product.

[1] Patent: WO2009/111279, 2009, A1. Location in patent: Page/Page column 81
[2] Canadian Journal of Chemistry, 1988, vol. 66, # 3, p. 420-428
[3] Patent: WO2012/83117, 2012, A1. Location in patent: Page/Page column 126-127
[4] Patent: WO2018/13867, 2018, A1. Location in patent: Paragraph 506