Study Of Condensation Reaction Of 9-Fluorenone With Phenol Catalyzed By Br(?)nsted Acidic Ionic Liquids

The reactions which are catalyzed by acid is one of important reactions in chemistry and chemical industry. Preparation, characterization and evaluation of Acidic catalysts is a important research field in oil refining and chemical industry,and it is also a key part of the synthesis of fine chemicals of high added value at the same time.Traditional acidic catalysts exist many disadvantages, such as equipment corrosion, dosage is large, catalyst is difficult to reuse, easy deactivation and environmental pollution,etc. In recent years, Br(?)nsted acid ionic liquids have provided a new choice for developing acidic catalyst with the in-depth study of ionic liquids.In this paper,twelve different kinds of SO3H-functionalized Br(?)nsted acidic ionic liquids have been synthesized by using triethylamine, pyridine and N-methyl imidazole and 1,3-propane sulfonic lactone as the raw material.Their structures, acidity were characterize by 1H/13C-NMR?IR and UV-vis respectively.The relationship between their structures and acidty are confired.Bisphenol fluorene is a kind of important chemical raw material, widely used in the synthesis of all kinds of new polymeric materials.In this paper we choose the condensation reaction of 9-fluorenone with phenol as the probe reaction using the SO3H-functional Br(?)nsted ionic liquids as the catalyst. Firstly,reaction conditions were optimized. Secondly, catalytic performance of Br(?)nsted acidic ionic liquids were compared.Lastly, the recycle of Br(?)nsted acid ionic liquids were investigated preliminarily.After the analysis of experimental data,we have gotten the following conclusions.The optimum synthetic conditions as follows, n(phenol):(9-fluorenone):n(IL)=6:1:0.125, V(co-catalyst)= 0.025mL,T=110?, t=6.5h.The results of catalytic performance of twelve kinds of Br(?)nsted acidic ionic liquids show that the catalytic properties of ionic liquids is affected by their acidity. The acidity is too low, the catalytic effect is not ideal.For exemple, Br(?)nsted acidic ionic liquids which anion is HSO4-? BF44-?P-CH3C6H4SO3- exhibited high activities for condensation of 9-fluorenone and phenol. The conversion of 9-fluorenone are 100% and the average selectivity of BHPF is about 87%;Br(?)nsted acidic ionic liquids which anion is H2PO4- exhibited low activities. The selectivity of BHPF are lower than 40%.After reaction,water is added to separate ionic liquid and products by extraction. The Br(?)nsted acidic ionic liquids through simple processing can be reused five times and without noticeably decreasing the catalytic activity...