Study On The Supported Solid Catalysts For Friedel-Crafts Acylations Of Arenes

Arone compounds are important fine chemical intermediates and widely applied in dye, agricultural chemicals and pharmaceuticals. Friedel-Crafts acylation reaction of acyl chloride with arenes is one of the promising methods for the preparation of these kinds of compounds. The Friedel-Crafts acylation reaction over two kinds of solid catalysts is systematically investigated and a continuous process for the synthesis of arone compounds is established in this paper.1?The synthesis of arone compounds from Friedel-Crafts acylation reaction of benzoyl chloride with toluene was taken as a model for the investigation into the performance of solid catalysts. A series of catalysts were prepared and examined, and FeCl₃/SiO₂ was chosen as the best catalyst. Over 90% conversion of benzoyl chloride was observed under the optimum reaction conditions?110 oC reaction temperature,10 h reaction time, 15wt% catalyst addition?. Catalysts of FeCl₃/SiO₂?FeCl₃/HY and FeCl₃/Al₂O₃ were catalyzed by BET?NH3-TPD and Py-IR. It was found that FeCl₃/SiO₂ has larger pore size and pore volume than other catalysts, which made the nice performance of catalyst FeCl₃/SiO₂, thus it could promoted the progress of the reaction.Meanwhile, the generality of the catalyst was demonstrated by the acylations of alkyl substituted aromatics. The results proved over 90% conversion of benzoyl chloride were obtained. Fathermore, the catalyst was reused for four runs with slight loss in catalytic activity.2?Friedel-Crafts acylation reaction of benzoyl chloride with meta-xylene was taken as a model for the investigation into the performance of solid catalysts. A series of supports and active components were prepared and examined, and FeTPA/TiO₂ was chosen as the best catalyst for this model of reaction. It proved that although there were a few total acids of FeTPA/TiO₂, catalyst of FeTPA/TiO₂ owned much more Lewis acid sites. The acyl chloride interacted with the catalyst to yield the corresponding complex. Subsequently, the de-chloridion of acyl chloride would proceed to form benzoyl cation. Therefore, the catalyst of FeTPA/TiO₂ exhibited the excellent catalytic activity. After that, the reaction parameters were optimized. Under the optimized conditions, 96.9% conversion of benzoyl chloride and 96.9% selectivity were obtained.According to the data of experimental and characterization of catalysts, catalyst of TPA/TiO₂ would enjoy the reaction of anisole with acetic anhydride. This might be the different acetylation reaqents interacted with the catalyst to yield the different acyl action. So the catalyst exhibited the distinct catalytic activity. The pore structure and the acidity of these catalysts were characterized. It was found that the Bronsted acid of TPA/TiO₂ was stronger than others.