PROCESS FOR ALKYLATING AROMATIC HYDROCARBONS

Process for alkylating an aromatic hydrocarbon wherein said hydrocarbon is reacted with a member of the group consisting of the olefines and the alkyl halides in the presence of a Lewis acid of the formula R M Xn-1, in which R is a monovalent organic radical having one - 20 carbon atoms, selected from the group consisting of the alkyl, cycloalkyl, aryl, aralkyl and alkoxy groups, X is a halogen atom or an electronegative group, M is a metal from groups IIIb, IVb and Vb of the periodic classification of the elements and n is the highest valence of the metal, said process comprising using water in a molar proportion of from 0.01 to 5 times that of the Lewis acid.