Abstract: A predetermined 2,4'-isomer content in a polyamine reaction mixture resulting from the aniline/formaldehyde condensation reaction can be achieved.Aniline and formaldehyde can be condensed in the presence of solid acidic catalysts to form a mixture of the following amines: ##STR1## WHERE N IS AN INTEGER OF FROM 1 TO 3. The amount of 2,4'-isomer can be varied between 30 and 95 wt. % of the diamine component of the mixture by conducting the condensation reaction in the presence of an acid activated clay catalyst at a reaction temperature of about 80.degree. to about 300.degree. C. When the reaction is conducted in the presence of a silica-alumina cracking catalyst or a silica-magnesia catalyst, the 2,4'-isomer content can be varied from about 15 to about 50 wt. %. In using the latter class of catalyst it is possible to prevent formation of a secondary amine by conducting the condensation reaction at a lower temperature and then digesting at a temperature of from about 175.degree. to about 220.degree. C.