Iodoethane → HCID 22288403, compound

Participants

Reaction Steps

A mixture of ethyl 5-(5-trifluoromethyl-1H-pyrazol-3-yl)thiophene-2-carboxylate, ethyl iodide, potassium carbonate and DMF was stirred at room temperature for 9 hours. The residue obtained by a usual treatment was eluted by silica gel chromatography (eluent; n-hexane:ethyl acetate=15:1) to give ethyl 5-(1-ethyl-5-trifluoromethyl-1H-pyrazol-3-yl)thiophene-2-carboxylate as colorless needle crystals. Also, by changing the eluent of the silica gel chromatography to n-hexane:ethyl acetate=10:1, ethyl 5-(1-ethyl-3-trifluoromethyl-1H-pyrazol-5-yl)thiophene-2-carboxylate was obtained as a light yellow oil. By hydrolyzing these compounds with a base in the usual way, a) 5-(1-ethyl-5-trifluoromethyl-1H-pyrazol-3-yl)thiophene-2-carboxylic acid and b) 5-(1-ethyl-3-trifluoromethyl-1H-pyrazol-5-yl)thiophene-2-carboxylic acid were obtained.

Provenance & Evidence