The Research Of Friedel-Crafts Alkylation Reaction Catalysts And The Application Of Alkylation Reaction Product

The Friedel-crafts alkylation reactions of phenolic compounds are one of the important routes for the synthesis of many chemical intermediates.The preparation and application of effective and environmental catalysts for the Friedel-crafts alkylation have become a hot research area.This thesis focused on the screening,preparation and modification of the existing Friedel-crafts alkylation catalysts.These catalysts were employed in the Friedel-crafts alkylation reactions of two phenolic substrates to find the optimum catalytic reaction condition through the comparison of their catalytic performances.Additionally,the applications of alkylated products in the synthesis of Schiff base ligands and stilbenes were also investigated and obtained some positive experimental results by now.The thesis mainly discusses the following aspects:In the first chapter,the current research progress on the Friedel-crafts alkylation reactions were briefly introduced.The classification and application of Friedel-crafts alkylation catalysts were also summarized.In the second chapter,the various acid catalysts including Lewis acids,protonic acid,strong solid acid,cation exchange resin and heteropoly acid were used to investigate the alkylated products and yields in the Friedel-crafts alkylation reactions by using p-hydroxyphenylacetic acid or p-cresol as the starting material and tert-butanol as the alkylating agent.Some of the acid catalysts were modified and loaded,then employed in the alkylation reactions to compare their changes of catalytic performances.In the third chapter,three SO3 H functional ionic liquids were prepared by the reactions of N-methyl imidazole,triethylamine and pyridine with 1,4-butane sultone,respectively and their structures were characterized by NMR spectrum.These SO3 H functional ionic liquids were applied in the butylation reactions of p-hydroxyphenylacetic acid and their catalytic performances were studied.In the fourth chapter,one of the alkyated products,3-tert-butyl-4-hydroxyl-phenyl acetic acid was employed in the synthesis of Schiff base ligand.The li gand was prepared by the methyl esterification,formylation and Mannich reaction,and the ligand structures were characterized.In the fifth chapter,another alkylated product,3,5-di-tert-butyl-4-hydroxyphenyl acetic acid,was used in the synthesis of stilbene derivative.The Perkin condensation of 3,5-di-tert-butyl-4-hydroxyphenyl acetic acid with 3,5-dimethoxyl-benzaldehyde afforded the cis-stilbene,which was then subjected to the methyl esterification.The esterified product was treated with oxidative coupling reaction and the couplingproducts were separated and characterized.The screening,modification,preparation and application of Friedel-crafts alkylation catalysts were investigated.It was found that concentrated sulfuric acid exhibited good catalytic activity and selectivity in the alkylation reactions of phenolic compounds,and SO3 H functional ionic liquids were effective,environmental and reused Friedel-crafts alkylation catalysts.In addition,two different tert-butylated products of p-hydroxyphenylacetic acid were applied in the successful synthesis of a new Schiff base ligand and stilbene compounds.Our research results have certain reference value to the synthesis of application of polyalkylated phenolic compounds.