the diphenylamine content of the final product is dependent upon the efficiency of the distillation unit the residue is easily removed from the distillation system as indicated above the excess phenolic compound is recycled thereby providing a high yield and overall conversion while at the same time providing a highly pure product the foregoing process is repeated with about 5 moles of aniline about 8 3 moles of m cresol and about 0 45 moles of anhydrous ferric chloride the resulting product comprises about 92 percent by weight 3 methyldiphenyl amine and about 8 percent by weight diphenylamine as opposed to the reaction described above which gave a product containing 97 percent by weight 3 methyl diphenylamine and 3 percent by weight diphenylamine this clearly illustrates that the degree of self condensation of aniline is dramatically affected by the ratio of primary aromatic amine and substituted phenol employed the foregoing process is repeated with about 5 moles of aniline about 16 6 moles of m cresol and no catalyst no significant amount of 3 methyldiphenylamine could be detected by liquid and gas chromatography at the end of the reaction this clearly demonstrates that this reaction will not proceed in the absence of a catalyst since the reactants will boil away at temperatures above their boiling points and since the.