ACYLATION OF TOLUENE WITH ISOBUTYRYL CHLORIDE

摘要

Acylation of toluene in a liquid phase was investigated on the series of zeolites Y, ZSM-5, mordenite and Beta differing in the structure and geometry of their channel systems and chemical composition. The highest conversion of isobutyryl chloride after 240 min of the reaction was achieved with large pore zeolites Beta and Y having three-dimensional channel system and possessing Si/Al ratio between 15-40. It was observed that the conversion of isobutyryl chloride increases with the increase in the pore size dimensions. Over medium pore zeolite ZSM-5 and large pore one-dimensional mordenite isobutyryl chloride conversions were substantially lower due to the slow desorption and transport of bulky p-isobutyryl toluene, which is strongly held in the channel system of these zeolites. A reaction pathway for acylation reaction was proposed involving the formation of isobutyric anhydride as a reaction intermediate, which is also responsible for acylation of toluene.