Dimethyl Sulfoxide → (2'-Oxo-1',2'-dihydrospiro[oxane-4,3'-pyrrolo[3,2-b]pyridin]-6'-yl)boronic acid

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Reaction Steps

An oven dried resealable Schlenk tube was charged with 6′-bromo-2,3,5,6-tetrahydrospiro[pyran-4,3′-pyrrolo[3,2-b]pyridin]-2′(1′H)-one (preparation 30, 0.350 g, 1.24 mmol), bis(pinacolato)diboron (0.470 g, 1.85 mmol), potassium acetate (0.240 g, 2.48 mmol) and dimethylsulphoxide (4 mL). The Schlenk tube was subjected to three cycles of evacuation-backfilling with argon, and 1,1′-bis(diphenylphosphino)ferrocene-palladium(II) dichloride dichloromethane complex (0.06 g, 0.07 mmol) was added. After three further cycles of evacuation-backfilling with argon, the Schlenk tube was capped and placed in an oil bath at 110° C. After 16 hours, the mixture was cooled and ethyl acetate was added and the organic layer was extracted with 2M aqueous hydrochloric acid. The aqueous phase was washed with ethyl acetate and then the pH of the solution was adjusted to 6 with 6M aqueous sodium hydroxide solution and extracted with ethyl acetate. The organic layer was dried (MgSO4) and evaporated to give the title compound in quantitative yield as a brown oily residue, which was used without further purification.

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