In this paper, 2-isopropyl naphthalene has been synthesized by the reaction of naphthalene and isopropyl bromide, using triethylamine hydrochloride-aluminum chloride ionic liquid as the catalyst. The effect of the catalyst composition, the reaction time, the reaction temperature, the ionic liquid dosage, as well as the molar ratio of the reagents on the 2-isopropyl naphthalene yield was systematically investigated. The optimal reaction conditions cover: an AlCl3 to Et3NHCl ratio of 2.0, a reaction time of 3 h, a reaction temperature of 15.0 ℃, a volume fraction of ionic liquid to the mixture(isopropyl bromide, n-dodecane and n-hexane) of 9%, and a naphthalene/isopropyl bromide molar ratio of 4.0. Under the optimal reaction conditions, the conversion of isopropyl bromide reached 98% and the selectivity of 2-isopropyl naphthalene was equal to 80%. The test results verified good catalytic activity upon using Et3NHCl-AlCl3 ionic liquid as the catalyst for alkylation of naphthalene with isopropyl bromide. The activity of the ionic liquid remains unchanged after it has been recycled for 4 times.
In this paper, 2-isopropyl naphthalene has been synthesized by the reaction of naphthalene and isopropyl bromide,using triethylamine hydrochloride-aluminum chloride ionic liquid as the catalyst. The effect of the catalyst composition, thereaction time, the reaction temperature, the ionic liquid dosage, as well as the molar ratio of the reagents on the 2-isopropylnaphthalene yield was systematically investigated. The optimal reaction conditions cover: an AlCl3 to Et3NHCl ratio of 2.0,a reaction time of 3 h, a reaction temperature of 15.0 ℃, a volume fraction of ionic liquid to the mixture (isopropyl bromide,n-dodecane and n-hexane) of 9%, and a naphthalene/isopropyl bromide molar ratio of 4.0. Under the optimal reaction conditions,the conversion of isopropyl bromide reached 98% and the selectivity of 2-isopropyl naphthalene was equal to 80%.The test results verified good catalytic activity upon using Et3NHCl-AlCl3 ionic liquid as the catalyst for alkylation of naphthalenewith isopropyl bromide. The activity of the ionic liquid remains unchanged after it has been recycled for 4 times.