Nitrones In The Synthesis Of Ionic Liquid,

Green chemistry,which aims to eliminate the pollution from the cradle,is becoming the hotspot and the foreland in chemical research.The conventional chemical reaction and its related industry are two of those main sources of pollution. Most of the waste is originated from volatile organic compounds(VOC).Therefore,it is espcially important to find green solvents as alternatives to conventional organic solvents.Fortunately,the recent emerged room temperature ionic liquids(RTILs)are promising to solve this problem,due to their unique physical and chemical properties such as non-toxicity,negligible volatility,non-flammability,excellent thermal stability,wide liquid range(-100～200℃),the ease of recovery and good ability to dissolve many kinds of organic and inorganic compounds.Furthermore,the polar of ionic character can change the reaction pathway and make the catalyst more active and stable.This made sense in minimizing and eliminating pollution.The application of RTILs in synthesis of nitrone derivatives was evaluated in the dissertation.The synthesis of nitrone derivatives from N-phenylhydroxyamine with substituted aldehyde was investigated in ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate([bmim]BF₄),which replaced traditional solvents,at room temperature.We have synthesized 13 difference nitrones and identified their structures.Comparison of the traditional method,it suggested that[bmim]BF₄ was an excellent solvent and catalyst in the synthesis of nitrone derivatives.Significant enhancements in reactivity,yield and reaction rate were achived in this method.The products could be recovered by simple filtration.[bmim]BF₄ could be recycled simply by moving water under vacuum and reused at least 5 times without any loss of activity.Therefore,1-butyl-3-methylimidazolium hexafluorophosphate([bmim]PF₆) was applied in the synthesis of nitrone derivatives at room temperature.Comparison of [bmim]BF₄,[bmim]PF₆ was comlex in separation and the yield of the compounds was relatively low,but the ionic liquid[bmim]PF₆ conld also be reused without any loss of activity.