Cesium carbonate → Ethyl 1-(2-fluoroethyl)-1H-pyrazole-5-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of ethyl 1H-pyrazole-3-carboxylate (0.77 g) (available from ABCR) in acetonitrile (30 ml) was added cesium carbonate (1.79 g) and the mixture stirred for 5 min when 1-fluoro-2-iodoethane (0.96 g) was added and the mixture stirred at 20° C. for 18 h. The mixture was evaporated and the residue taken up in water (30 ml) and DCM (30 ml) separated by hydrophobic frit and concentrated to ˜5 ml, placed on an SPE cartridge (50 g silica) and eluted with a gradient of ethyl acetate in cyclohexane to give the Ethyl 1-(2-fluoroethyl)-1H-pyrazole-5-carboxylate (0.42 g) as a colourless oil.

Provenance & Evidence