Iodoethane → HCID 22288403, Verbindung

Reaktionsgleichung

[F:1][C:2]([F:19])([F:18])[C:3]1[NH:7][N:6]=[C:5]([C:8]2[S:12][C:11]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[CH:10][CH:9]=2)[CH:4]=1.[CH2:20](I)[CH3:21].C(=O)([O-])[O-].[K+].[K+]>CN(C=O)C>[CH2:20]([N:7]1[C:3]([C:2]([F:18])([F:1])[F:19])=[CH:4][C:5]([C:8]2[S:12][C:11]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[CH:10][CH:9]=2)=[N:6]1)[CH3:21]

Komponenten

Versuchsvorschrift

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.