1-Methyl-3-(2',2',2'-trifluoroethyl)imidazolium triflate → 1-methyl-3-(2',2',2'-trifluoroethyl)imidazolium N-(trifluoromethanesulfonyl)-trifluoroacetamide

1-Methyl-3-(2′,2′,2′-trifluoroethyl)imidazolium triflate (10 mmol) and water (10 ml) were placed in a reaction vessel, and a solution of sodium N-(trifluoromethanesulfonyl)trifluoroacetamide (2.94 g, 11 mmol) and water (3 ml) were added thereto while stirring. The mixture was then stirred for 15 minutes. The lower oil layer was separated, and this layer was repeatedly washed with water. The obtained oil product was dehydrated using a vacuum pump at 110° C. for 3 hours, and 1-methyl-3-(2′,2′,2′-trifluoroethyl)imidazolium N-(trifluoromethanesulfonyl)-trifluoroacetamide (compound 12) was obtained (yield 2.87 g, 70%). When further purification is required, the oil product may be dissolved in a small amount of ethyl acetate, and a large amount of ether may be added thereto to separate the oil product and the product may be dried. Alternatively, when the product is colored, it may be treated with active carbon. Physical property, elemental analysis and spectral data of the compound 12 are shown in Table 8.