Isopropylbenzene (IPB), a high-octane component of gasoline, is obtained by alkylation of benzene with propylene. alpha-Methylstyrene, a rubber base, is obtained from IPB by dehydrogenation and phenol, used for treatment of petroleum oils, is obtained by oxidation. In industrial conditions, this process is conducted in the presence of a catalytic complex of aluminum chloride with polyisopropylbenzenes.