己内酰胺三氟甲磺酸离子液体中甲苯的区域选择性硝化

以三氟甲磺酸和己内酰胺为原料制备了一种新型离子液体己内酰胺三氟甲磺酸([CP]OTf)，用1HNMR、FTIR对其结构进行了表征。并把[CP]OTf作为催化剂和溶剂，用于催化甲苯的硝化反应。借助气相色谱研究了[CP]OTf的用量、硝化温度、反应时间、硝酸浓度和离子液体的重复使用等因素对甲苯硝化反应区域选择性和产率的影响。结果表明：在反应温度55℃，反应时间6h，甲苯与95%浓硝酸的摩尔比为1：1，离子液体用量占甲苯摩尔数的15%时，产物中邻对位硝基甲苯摩尔比为1.12，较浓硫酸催化硝化的相应值(1.67)显著降低，硝基甲苯的产率达到78.41%，[CP]OTf表现出了优良的催化活性和对位选择性。[CP]OTf) 重复使用5次，其催化活性及对位选择性变化很小。

Regioselective Nitration of Toluene in Caprolactam-trifluoromethanesulfonic Acid Ionic Liquid

A novel ionic liquid Caprolactam-trifluoromethanesulfonic acid ([CP]OTf) was prepared with trifluoromethanesulfonic acid and Caprolactam as raw material. The structure of the ionic liquid was characterized by 1HNMR and FTIR. It was used as the catalyst and solvent in the nitration of toluene. The effects of the amount of catalyst, reaction temperature, reaction time, the concentration of nitric acid and recycling of catalyst on product yield and para-selectivity for the nitration of toluene was investigated with the aid of gas chromatography. The results showed that, when the nitration temperature was 55℃, the reaction time was 6h, the molar ratio of toluene to 95% nitric acid was 1:1, the amount of catalyst was 15% of the molar of toluene, the ortho-para isomer ratio reached 1.12, far below 1.67 by using sulfuric acid, and gave a product yield of 78.41%. Ionic liquid [CP]OTf showed high regioselectivity and catalytic activity. The catalyst could be reutilized up to five times with little decrease in activity and regioselectivity.