1-Methylimidazole → 1-Methyl-3-hexyl-imidazolium hexyl sulfonate salt

Participants

Reaction Conditions

Reaction Steps

To a 50 ml four necked flask equipped with a stirrer, a dropping funnel, cooling tube and a thermometer, 41.05 g (0.5 mol) of 1-methyl imidazole and 50 ml of toluene were charged and, after heating at 80° C., 146.52 g (0.55 mol) of dihexyl sulfonic acid was dropped slowly taking one hour or more. They were stirred at a refluxing temperature for 25 hours. After cooling, solvent cleaning was conducted with toluene to obtain 156.83 g of 1-methyl-3-hexyl-imidazolium hexyl sulfonate salt by drying under a reduced pressure. Then, 99.13 g of the obtained 1-methyl-3-hexyl imidazolium hexyl sulfonate salt was dissolved in 80 ml of water, and a solution in which 139.24 g of lithium bis(trifluoromethane sulfonyl) imide was dissolved in 80 ml of water was added thereto at a room temperature and stirred. From separated two layers, the lower layer was fractionated and by-products were removed by adding 40 wt % of purified water and by water washing five times, and vacuum drying was applied to obtain 197.31 g of 1-methyl-3-hexyl imidazolium bis(trifluoromethane sulfonyl) imide. As a result of ICP analysis, the total alkali metal was 2.7 ppm or less, the chloride ion was 0.7 ppm and each of iodide and bromide ions was 0.1 ppm or less (less than ICP detection limit).

Provenance & Evidence