离子液体中挂式四氢双环戊二烯的合成

Synthesis of Exo-tetrahydrodicyclopentadiene in Ionic Liquids

制备了卤化烷基咪唑、卤化烷基吡啶类氯铝酸离子液体,并以其为催化剂和反应介质,通过桥式四氢双环戊二烯(endo-THDCPD)的异构化反应合成了挂式四氢双环戊二烯(exo-THDCPD)。系列氯铝酸离子液体中endo-THDCPD几乎完全转化为exo-THDCPD。50℃,三氯化铝与氯化1-甲基-3-丁基咪唑的摩尔比为1.5,离子液体与桥式四氢双环戊二烯的摩尔比为1.0,3 h,收率98.3%;三氯化铝与氯化丁基吡啶的摩尔比为1.8,离子液体与桥式四氢双环戊二烯的摩尔比为0.5,3 h,收率97.8%。分离后的离子液体重复使用五次,其催化活性保持不变。离子液体中的异构化反应不需溶剂,收率高、易分离。

Synthesis of exo-tetrahydrodicyclopentadiene（exo-THDCPD） in ionic liquids was studied.Ionic liquids were prepared by aluminum chloride and dialkylimidazolium halide or alkylpyridinium halide and were used in isomerization of endo-tetrahydrodicyclopentadiene（endo-THDCPD） as catalyst and solvent.Effects of reaction conditions such as reaction temperature,reaction time,and ionic liquid amount on the conversion of endo-THDCPD and yield of exo-THDCPD were studied.Results show that the conversion of endo-THDCPD is 100% in different ionic liquids.The yield of exo-THDCPD is 98.3% in 1,3-dialkylimidazolium chloride/aluminum chloride（n（AlCl3）n（Cl=1.5） at 50 ℃ for 3 h.The yield of exo-THDCPD is 97.8% in 1-butylpyridinium chloride/aluminum chloride（n（AlCl3）n（Cl=1.8） at 50 ℃ for 3 h.The product can be simply separated and ionic liquids can be reused at least five times without decreasing of the catalytic activity.