Alkylation of 1,3,5-trimethylbenzene with gamma-butyrolactone catalyzed by AlCl3 and Nafion-H

作者：Xu YZ^*; Mao JX; Ma LJ; Cao D; Lin DX; Zheng XM

来源：Chinese Journal of Catalysis, 2005, 26(3): 248-252.

• 1, 3, 5-trimethylbenzene
• gamma-butyrolactone
• alkylation
• 4-(2, 4, 6-trimethylphenyl)-butyric acid
• Nafion-H
• aluminium chloride

The alkylation product 4-(2,4,6-trimethylphenyl)butyric acid could be synthesized via the reaction of 1 3, 5-trimethylbenzene with gamma-butyrolactone catalyzed by AlCl3 at room temperature. The catalyst amount and reaction time were important factors affecting the product yield. The gamma-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 AlCl3 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 degrees C, while the selectivity was about 90%. Nafion-H could be reused after simply washing and drying, but its activity decreased by 4% similar to 5% with each use. A reaction mechanism under the Nafion-H catalysis was proposed, in which the activation of gamma-butyrolactone was the key step. The acid catalyst Nafion-H made the C-O bond in the 4-position of gamma-butyrolactone broken to form an active intermediate, which further reacted with 1, 3, 5-trimethylbenzene to produce 4-(2,4,6-trimethylphenyl)butyric acid.

• 出版日期2005-3
• 单位浙江大学