PURPOSE: To make trimethylindane heavier and reduce the quantity thereof by distilling away the unreacted benzene and cumene from a reaction product of the benzene with propylene and treating the resultant mixture containing polyisopropylbenzene and trimethylindane with an acid.
CONSTITUTION: Benzene and propylene are subjected to alkylating reaction in the presence of a Friedel-Crafits' catalyst containing AlCl3 to provide a reaction product containing cumene, polyisopropylbenzene, the unreacted benzene and trimethylindane formed as a by-product. The resultant reaction product, together with the polyisopropylbenzene recycled from a distillation step, is then subjected to transalkylating reaction. The obtained reaction product is subsequently distilled to distill away the cumene and the unreacted benzene and a mixture solution containing the polyisopropylbenzene and the trimethylindane is then treated with an acid at 150-180°C using AlCl3, sulfuric acid, a cation type exchange resin, SiO2/Al2O3, etc., to make the trimethylindane heavier and reduce the quantity thereof.
