Ionic Liquid Modified And Applied Research

In order to improving the effect of ionic liquids in alkali system, the imidazole ionic liquids are modified and the applications of modified ionic liquids in synthesis of chalcone and phthalimide are studied.When taking research on the modified ionic liquids, two imidazole ionic liquids 1-butyl-2,3-dimethylimidazolium tetrafluoroborate ([bdmim]BF₄, named iail-B) and 1-butyl-2,3-dimethylimidazolium hexafluorophosphate ([bdmim]PF₆, named iail-P) are prepared by two steps, using 1,2-dimethylimidazole, 1-butylbromide, fluorophosphate and fluoroborate as materials. The first step is preparation of intermediate 1-butyl-2,3-dimethylimidazolium bromine ([bdmim]Br), using 1,2-dimethylimidazole and 1-butylbromide as materials. Better conditions of preparation are gained by investigating the effect of solvent, materials mol ratio, reaction temperature and time to yield. The yield of [bdmim]Br is 98.14 %. As to the second step, two modified ionic liquids iail-B and iail-P which is inert to alkali are prepared by exchanging anion Br^- which is from [bdmim]Br for BF₄^- and PF₆^- which are from fluoroborate and fluorophosphates. Better conditions of preparation are gained by investigating the effect of solvent, materials mol ratio, reaction temperature and time to yield. The yields of iail-B and iail-P are 89.25%, 90.95% respectively. Basd on their preparation of modified ionic liquids iail-B and iail-P, the applications in alkali catalysis as solvent are studied. The synthesis of Chalcone from benzaldehyde and acetophenone catalyzed by NaOH is selected for iail-B. And, the synthesis of phthalimide from urea and phthalic is selected for iail-P. As a result, the yield and purity of target products are improved when using iail-B and iail-P as solvent. Yield and purity of Chalcone are 97.89% and 97.53% respectively. Yield and purity of phthalimide are 97.60% and 99.34% respectively. What's more important is that the modified ionic liquids could be recycled as solvent in alkali catalysis. That provides a feasible method for green synthesis.