在AlCl_3和Nafion-H的催化作用下均三甲苯与γ-丁内酯的烷基化反应  

Alkylation of 1,3,5-Trimethylbenzene with γ-Butyrolactone Catalyzed by AlCl_3 and Nafion-H

作　　者：徐羽展[1] 毛建新[1] 马令娟[1] 曹丹[1] 林定选[1] 郑小明[1] 

机构地区：[1]浙江大学西溪校区催化研究所,浙江杭州310028

出　　处：《催化学报》2005年第3期248-252,共5页

基　　金：国家教委留学回国人员基金;浙江省教委留学回国人员基金资助项目

摘　　要：在无水AlCl3 的催化作用下 ,均三甲苯与γ 丁内酯在室温下即可发生烷基化反应生成 4 (2 ,4 ,6 三甲基苯基 )丁酸 .实验结果表明 ,催化剂用量和反应时间是影响反应产物收率的重要因素 ,选择合适的反应条件可使γ 丁内酯几乎定量地转化为目标产物 .在固体高分子酸性树脂Nafion H的催化作用下 ,4 (2 ,4 ,6 三甲基苯基 )丁酸的收率随着温度的升高而升高 ,在 2 0 0℃下收率达到最大值 84 5 % ,选择性保持在 90 %左右 .Nafion H经过简单的溶剂洗涤和干燥处理后可重复使用 ,但每次重复使用后收率下降 4 %～ 5 % .对Nafion H催化下该反应可能的机理进行了探讨 .The alkylation product 4-(2,4,6-trimethylphenyl)butyric acid could be synthesized via the reaction of 1,3,5-trimethylbenzene with γ-butyrolactone catalyzed by AlCl 3 at room temperature. The catalyst amount and reaction time were important factors affecting the product yield. The γ-butyrolactone could be converted to the product quantitatively under certain reaction conditions, but it was not suitable for industrial application because of its environmental pollution. Therefore, some polymer resins were chosen to replace AlCl 3 in order to make this process much more friendly to the environment. Nafion-H was the best among the polymer resins in terms of both the product selectivity and yield. The yield of 4-(2,4,6-trimethylphenyl)butyric acid increased with the increase of reaction temperature and reached the maximum value of 84.5% at 200 ℃, while the selectivity was about 90%. Nafion-H could be reused after simply washing and drying, but its activity decreased by 4%～5% with each use. A reaction mechanism under the Nafion-H catalysis was proposed, in which the activation of γ-butyrolactone was the key step. The acid catalyst Nafion-H made the C-O bond in the 4-position of γ-butyrolactone broken to form an active intermediate, which further reacted with 1,3,5-trimethylbenzene to produce 4-(2,4,6-trimethylphenyl)butyric acid.

关 键 词：均三甲苯 Γ-丁内酯 烷基化 4-(2 4 6-三甲基苯基)丁酸 NAFION-H 氯化铝 

分 类 号：O643[理学—物理化学]