942919-26-8

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4-(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrrolo[2,3-b]pyridine is used in organic synthesis, in particular, that of novel potent and selective Tetrahydropyrazolo[1,5-a]pyrazines as ATR inhibitors.

The general procedure for the synthesis of 7-azaindole-4-boronic acid pinacol ester from pinacol ester of bis-boronic acid and 4-chloro-7-azaindole was as follows: 4-chloro-1H-pyrrolo[2,3-b]pyridine (457 mg, 3 mmol), palladium acetate (13.2 mg, 2 mol%), 2-(dicyclohexylphosphino)biphenyl (42 mg, 4 mol%), bis(pinacol co ) ethylborane (1.5 g, 6 mmol) and potassium acetate (590 mg, 6 mmol) were dissolved in degassed dioxane (10 mL) under nitrogen atmosphere. The reaction mixture was stirred at 100 °C for 5 h, subsequently cooled to room temperature and filtered through a thin diatomaceous earth pad (eluting with ethyl acetate). The filtrate was washed sequentially with water and brine, dried over anhydrous magnesium sulfate, filtered and concentrated under reduced pressure. The residue was purified by fast column chromatography to afford the target product 7-azaindole-4-boronic acid pinacol ester (690 mg, 94% yield).

[1] Patent: WO2009/93981, 2009, A1. Location in patent: Page/Page column 106
[2] Patent: WO2010/101302, 2010, A1. Location in patent: Page/Page column 186
[3] Patent: WO2008/139161, 2008, A1. Location in patent: Page/Page column 137