反应详情

温度

130 °C

96 parts of 1-ethylimidazole, 135 parts of dimethyl carbonate and 192 parts of methanol were put into an autoclave made of a stainless steel equipped with a cooling condenser and mixed homogenously. After nitrogen substitution, the temperature was then raised to 130° C. while being sealed, so as to initiate a reaction. At the beginning, the pressure was approximately at 4.5 Kg/cm2, but it was gradually raised due to generation of carbon dioxide, so that the gasses were appropriately released from the upper part of the cooling condenser, adjusted at a pressure of about 7 Kg/cm2 or less. After 60 hours, they were cooled at 30° C., and the result of the reacted solution by means of 1H-NMR showed that 1-ethylimidazole was disappeared and 1-ethyl-3-methylimidazolium monomethyl carbonate was produced approximately under a quantitative theory. Into 415 parts of the resultant solution of 1-ethyl-3-methylimidazolium monomethyl carbonate, methanol and dimethyl carbonate, 205 parts of an aqueous solution of fluoroboric acid at a concentration of 42 wt % were gradually put in drops with stirring at a temperature of 25° C. over a period of about 30 minutes. As putting them in drops, bubbles of carbon dioxide were generated. Finishing the dropping and the generation of the bubbles, all the solvents were removed at a pressure of 20 Torr and at a temperature of 150° C., so as to obtain 194 parts of a transparent and colorless liquid (1). The examinations of 1H-NMR, 19F-NMR, 13C-NMR and HPLC of the liquid (1) resulted in showing that 98 mol % of 1-ethyl-3-methyl imidazolium tetrafluoroborate (which is hereinafter shortened as “EMI.BF4”), 2 mol %, in total, of 1-ethyl-3-methyl-4-carboxylate imidazolium, 1-ethyl-3-methyl-5-carboxylate imidazolium, 1-ethyl-3-methyl-4-carboxylate-5-carboxy imidazolium and 1-ethyl-3-methyl-4-carboxy-5-carboxylate imidazolium.

1. customequipped with a cooling condenser
2. additionmixed homogenously
3. customwhile being sealed
4. customa reaction
5. temperaturethey were cooled at 30° C.
6. customthe result of the reacted solution by means