Carbon Dioxide → HCID 178462721, compound

Participants

Reaction Conditions

Reaction Steps

110 parts of 1-ethyl-2-methylimidazole, as prepared, 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-ethyl-2-methylimidazole was disappeared and 1-ethyl-2,3-dimethylimidazolium monomethyl carbonate was produced approximately under a quantitative theory. Into 428 parts of the resultant solution of 1-ethyl-2,3-dimethylimidazolium 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 208 parts of a white solid (1). The examinations of 1H-NMR, 19F-NMR, 13C-NMR and HPLC resulted in showing that 98 mol % of 1-ethyl-2,3-dimethylimidazolium tetrafluoroborate (which is hereinafter shortened as “EDMI.BF4”), 2 mol %, in total, of 1-ethyl-2,3-dimethyl-4-carboxylate imidazolium, 1-ethyl-2,3-dimethyl-5-carboxylate imidazolium, 1-ethyl-2,3-dimethyl-4-carboxylate-5-carboxy imidazolium and 1-ethyl-2,3-dimethyl-4-carboxy-5-carboxylate imidazolium. The HPLC analysis was performed in the conditions as described above. The conditions were the same in the following examples.

Provenance & Evidence