新型PEG双子温控离子液体中的缩醛反应

制备了具备温控功能的新型PEG双子离子液体(IL200, IL400, IL1000), 考察了该离子液体和甲苯形成“高温均相, 低温两相”体系, 对芳香醛与乙二醇缩合反应的影响, 当离子液体3 mL, 甲苯5 mL, 对甲苯磺酸6 mmol, 苯甲醛5 mmol, 乙二醇15 mmol, 反应时间4 h, 温度80 ℃时, 产率达到92%. 该体系对芳香醛与乙二醇缩合反应有广泛的适用性, 且不经任何处理可多次循环使用.

Acetalization of Aromaldehyde and Ethyleneglycol in Novel PEG Thermoregulated Ionic Liquids

Novel PEG ionic liquids(IL200, IL400, IL1000) were prepared and used as the solvent for the acetalization of aromaldehyde and ethylene glycol catalyzed by p-toluenesulfonic acid. The ionic liquids and toluene have the advantages of both homogeneous and heterogeneous phases at different temperatures with the ease of product as well as catalyst separation. The catalyst(p-toluenesulfonic acid) was soluble in ionic liquids and insoluble in toluene. The optimum conditions: ILs 3 mL, toluene 5 mL, p-toluenesulfonic acid 6 mmol, benzaldehyde 5 mmol, ethylene glycol 15 mmol, the yield was 92% in 4 h at 80 ℃. The yields of the acatalization of aromaldehyde and ethylene glycol catalyzed by the system was 54.6%—97.8%. The ionic liquids played the role of solvent and the catalyst system were recycled up to 5 times without any significant loss of activity.