Alkylation of benzene with ethyl chloride catalyzed by ionic liquid

Et_3N·H-AlCl_3 ionic liquid as the catalyst was used in alkylation of benzene with ethyl chloride. The influence of reaction temperature, molar ratio of benzene to ethyl chloride, catalyst dosage, reaction time and the reusability of the ionic liquid were investigated. The results of qualitative analysis by GC-MS and quantitative analysis by GC showed that ethyl chloride conversion of 95.52% and selectivity to ethyl benzene of 83.43% were attained under the the optimum condition as follows : reaction temperature 60 ℃, molar ratio of benzene to ethyl chloride 10:1,catalyst dosage 10% of the total mass of benzene and ethyl chloride,and reaction time 15 min. Et_3N·H-AlCl_3 ionic liquid could be recycled,and the catalyst activity had no obvious change after repeated use for 4 times.