Process for the regeneration of zeolite catalysts

A process for the regeneration of a zeolitic catalyst which is at least partially exhausted by use in the synthesis of optionally substituted methylenedianiline (MDA) and derivatives thereof or of mixtures of optionally substituted MDA and derivatives thereof with a higher homologous product by a process comprising the re-arrangement reaction of the corresponding aminal intermediate of the condensation reaction between formaldehyde and optionally substituted aniline or a derivative thereof, which regeneration process comprises contacting, said catalyst with an aromatic compound, in at least partially liquid phase and at a temperature higher than that of the condensation and/or re-arrangement reaction in which the optionally substituted MDA and derivatives thereof is produced wherein the aromatic compound comprises a substituent having activating characteristics with respect to electrophilic substitution as compared to the aromatic compound without the said substituent wherein the substituent having activating characteristics is selected from NH2, —NHR, —NR2, —OH, —O−, —OR1, or —NHCOR2 substituents wherein R is hydrogen, a C1–C8 alkyl, C4–C10 cycloalkyl C6–C12 aromatic radical, R1 and R2 represent a C1–C4 (iso)alkyl, C4–C10 cycloalkyl, aromatic, alkylaromatic or C6–C10 arylakyl radical.