| 摘要 |
p-Dialkylbenzenes are produced by reaction of alkylbenzenes and olefins in the presence of an AlCl3/HCl catalyst also containing an aromatic hydrocarbon having a carbon-carbon double bond situated in conjugation to a benzene nucleus (which for convenience of definition is assumed to contain 3 conjugated double bonds). Suitable aromatic hydrocarbons include styrene, anthracene, 2 - phenyl - cyclohexene and 1,1,3-trimethyl - 5 - isopropylindene, others also being mentioned. m- and o-dialkylbenzenes and higher alkylated by-products may be transalkylated, e.g. with benzene or an alkylbenzene in the presence of a Friedel-Crafts catalyst. The examples are all directed to the production of p-diisopropylbenzene from cumene and propylene. In Example 6, the aromatic hydrocarbon catalyst component is 1,1,3-trimethyl-5-isopropyl-indene, and the process is carried out continuously in three vessels, in the first of which tri-isopropylbenzene by-product is transalkylated with benzene in the presence of AlCl3/HCl catalyst, a small amount of 1,1,3-trimethyl-5-isopropyl-indene being produced simultaneously, the whole mixture from this vessel then being passed to a second vessel together benzene, m-dialkylbenzene, AlCl3/HCl catalyst and o- and m-dialkylbenzene by-product further transalkylation taking place, and the cumene-propylene alkylation reaction taking place in the presence of the reaction mixture from the second vessel, by-products being separated and recycled to the first, second and third vessel as appropriate.
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