1-Acetoxy-2-bromoethane → 2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)-1H-pyrazol-1-yl)ethyl acetate

Participants

Reaction Steps

To a 20 mL pressure vial was charged pyrazole-4-boronic acid pinacol ester (5.15 mmol, 1.00 g) and DMF (10 mL). NaH (60% w/w in mineral oil, 5.67 mmol, 227 mg) was then added portion-wise. The resulting solution was stirred at room temperature for 10 minutes. 2-bromoethyl acetate (5.67 mmol, 623 μL) was then added dropwise. The vial was flushed with argon, sealed, and the reaction was stirred at 60° C. for 18 hours. At 18 hours, the DMF was removed in vacuo, and the residue taken up in DCM. This suspension was filtered through celite and then purified via flash chromatography to yield the title compound.

Provenance & Evidence