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

Participants

Reaction Conditions

Reaction Steps

4,4,5,5-Tetramethyl-2-(1H-pyrazol-4-yl)-1,3,2-dioxaborolane (5.0 g), N,N-dimethylacetamide (50 ml), potassium carbonate (5.3 g) and ethyl iodide (2.1 ml) were mixed, and the mixture was stirred at 60° C. overnight. The reaction mixture was cooled to room temperature, water (100 ml) and ethyl ether (100 ml) were added, and the mixture was partitioned in a separatory funnel. The aqueous layer was further extracted with ethyl ether (100 ml), and the organic layers were combined. The organic layer was washed 3 times with water (100 ml) and once with saturated brine (100 ml), dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated under reduced pressure, hexane (50 ml) was added to the obtained residue and the mixture was partitioned in a separatory funnel. The organic layer was washed 3 times with water (40 ml) and once with saturated brine (40 ml), dried over anhydrous sodium sulfate, and filtered. The filtrate was concentrated under reduced pressure to give the title compound (2.1691 g, 38%).

Provenance & Evidence