Cesium carbonate → 4-bromo-1-(2,2,2-trifluoroethyl)-1H-pyrazole

Participants

Reaction Steps

A 250 mL RB flask was charged with 4-bromo-1H-pyrazole (2.00 g, 13.6 mmol), 2,2,2-trifluoroethyl trifluoromethanesulfonate (2.35 ml, 17.0 mmol), cesium carbonate (8.87 g, 27.2 mmol), and 1,4-dioxane (40.0 ml, 468 mmol), capped, and stirred at room temperature for 20 hours. The reaction mixture was filtered and the solid washed with dioxane; the filtrate was then concentrated to give 4-bromo-1-(2,2,2-trifluoroethyl)-1H-pyrazole (2.402 g, 77.1% yield) as a crude oil.

Provenance & Evidence