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

Reaction equation

[Br:1][C:2]1[CH:3]=[N:4][NH:5][CH:6]=1.FC(F)(F)S(O[CH2:13][C:14]([F:17])([F:16])[F:15])(=O)=O.C(=O)([O-])[O-].[Cs+].[Cs+].O1CCOCC1>>[Br:1][C:2]1[CH:3]=[N:4][N:5]([CH2:13][C:14]([F:17])([F:16])[F:15])[CH:6]=1

Participants

Reactant 4

HCID 10796Cesium carbonate

HCID 163754-Bromopyrazole

HCID 312751,4-Dioxane

HCID 803662,2,2-Trifluoroethyl trifluoromethanesulfonate

Product 1

HCID 610302834-bromo-1-(2,2,2-trifluoroethyl)-1H-pyrazoleYield 77.1%

Procedure

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.