Improved integrated processes for the production of alkyl aromatic compounds are disclosed wherein aromatic compounds which may be treated for removal of deleterious substances are reacted with olefin compounds, which may also be treated for contaminant removal, in the presence of acidic zeolite catalyst(s) to produce the desired alkyl aromatic compound(s). The aromatic and preferably also the olefin feeds are treated substantially to remove contaminants, particularly the nitrogen compounds contained therein, before they are brought together for reaction in the presence of the zeolite catalyst(s). In accordance with the present invention, it has been found that feed pretreatment for removal of nitrogen compounds significantly improves the run length and life of the acidic zeolite catalyst(s). The feed pretreatment of this invention may include the steps of distillation, extraction, and/or adsorption by solid adsorbent, which may be regenerated in accordance with further embodiments of this invention.