Performance Study Of High Efficient And Clean Acylation Catalyst

Acid ionic liquid, because of its advantages of good solubility, low volatility and acidity adjust flexible, is considered to be a novel catalytic material to take place of the old catalyst.The predecessors have done a lot of workabout ionic liquid type and reaction system of research, but have not been able to overcome the problem of use large amount of ionic liquid. According to the acylation reaction mechanism, the need to use large amounts of ionic liquid because the product of aromatic ketones to produce strong complexation with ionic liquids. In order to reduce the amount of ionic liquid, the author choose low network cooperation catalyst under high temperature with low ionic liquid catalyzed acylation reaction, which can greatly reduce the amount of the catalyst.[Bmim]Cl, [Bmim]Br two kinds of ionic liquid precursor were synthesized and then mixed with anhydrous aluminum chloride, ferric chloride, zinc chloride, copper chloride, chromium chloride and obtained eight kinds ionic liquids. The structures of this catalyst were characterized by IR and 1HNHR. Acidic sites and the strength of this catalyst have been studied by acetonitrile-probe IR technique method.And analyze the rule between mole fraction of halide and the ionic liquids acidic strength.4-Methoxy benzophenone was synthesised with ionic liquid ([Bmim]Br-ZnCl2) used as catalyst.The most optimal conditions of the reaction were studied as follow:n([Bmim]Br-ZnCl2)/n(anisole)/n(benzoyl chloride)=1/60/20, reaction temperature 160℃, reaction time 4h, the mole fraction of ferric chloride x=0.67. In this condition, the yield of 4-Methoxy benzophenone is 90.2%.And in the most optimal condition,3,4-two methoxy 4’fluoride benzophenone was obtained by Friedel-Crafts acylation with high product yield 90.4%. The contract between ionic liquid and other types catalyst show that the ionic liquid catalytic activity is excellent and the ionic liquid [Bmim]Br-ZnCl2 can be recyled for five times without obvious yield decline.The ionic liquids were used as catalyst in the phenolic acylation,and synthesis 4-hydroxy benzophenone with phenol and benzoyl chloride. In this condition, the yield of 4-hydroxy benzophenone is 80.2%.And in the most optimal condition, a series of phenolic’F-C acylation reaction were made and obtained high product yields, all more than 80%. The ionic liquids were used as catalyst in the aromatic hydrocarbons acylation,and synthesis benzophenone with benzene and benzoyl chloride as raw material. In this condition, the yield of benzophenone is 74.2%.And in the optimal condition, a series of aromatic hydrocarbons’F-C acylation reaction were made and obtained high product yields all more than 70%. But far less than the yield of aromatic ethers and phenols, which is determined by the characteristics of aromatic hydrocarbons.Finally, the paper discusses to benzene and benzoyl chloride as the reaction system, using ionic liquid [Bmim]Br-ZnCl2 as catalyst, the catalytic reaction mechanism. Iron chloride acid ionic liquid activity is much better than several other ionic liquid is due to:First [Bmim]Br-ZnCl2 acid is moderately; Second the complex cooperation between the ionic liquid and product ketone is weak, at high temperatures can be seperate, so just a small amount of catalyst can make a high yield; Third, [Bmim]Br-ZnCl2 at room temperature was liquid and objects with reaction immiscibility of makes reaction in the process of free activity center has been gathered in the catalyst layer.