季铵盐离子液体催化苯胺选择性烷基化反应

对离子液体介质中苯胺与卤代烃的N-单烷基化反应,考察了9种不同结构的季铵盐、季鏻盐对反应的影响。结果表明,在60℃,用四丁基氯化铵作催化剂、三乙胺作缚酸剂,n(三乙胺)∶n(苯胺)∶n(卤代烃)∶n(四丁基氯化铵)=2∶1∶1∶0.05,苯胺能快速有效地与卤代烃发生N-烷基化反应,高选择性制备仲胺化合物,苯胺转化率达到86%,仲胺选择性达到87%,通过简单的乙醚萃取就可实现产物分离。季铵盐离子液体对邻位或对位有取代基的苯胺烷基化反应,也具有高的苯胺转化率和仲胺选择性,可以代替咪唑鎓盐离子液体用于苯胺选择性单烷基化反应。

Selective Alkylation of Anilines in Quaternary Ammonium Salt Ionic Liquids

The N-monoalkylation reaction of anilines with alkyl halides in the presence of ionic liquids was investigated.Tetrabutyl ammonium chloride (TBAC) was considered to be the best catalyst among the nine different structures of quaternary ammonium salts and quaternary phosphonium salts.Using TBAC as alkylation catalyst,and triethylamine as acid-acceptor,secondary amine was synthesized highly selectively through N-alkylation of aniline with alkyl halide.Under 60 ℃ with molar ratio n(triethylamine)∶n(aniline)∶n(alkyl halide)∶n(TBAC)=2∶1∶1∶0.05,the conversion rate of aniline reached 86%,while the selectivity of monoalkylation reached 87% and the product can be separated simply by extraction with ether.Meanwhile,this ionic liquid also has satisfactory catalytic effects on N-alkylation of ortho-or para-substituted aniline,i.e.the high conversion rate of aniline and selectivity of monoalkylation.