Iodoethane → 1-Ethyl-1H-pyrazole-4-boronic acid, pinacol ester

Participants

Reaction Steps

A mixture of 4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazole (0.05 g, 0.2 mmol), iodoethane (31 uL, 0.39 mmol, Sigma-Aldrich, Cat. No. 17780), and cesium carbonate (250 mg, 0.77 mmol) in acetonitrile (1 mL) was stirred at 90° C. for 2 h. After cooling it was quenched with water. The product was extracted with ethyl acetate. The extract was washed with water twice, brine once; dried over Na2SO4. After filtration the filtrate was concentrated to yield 34 mg of the product which was directly used in the next step reaction without further purification.

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