Synthesis of 4-aminodiphenylamine by electroreducing alkaline solutions of a sodium salt of 4-nitrosodiphenylamine

Conditions for the synthesis of 4-aminodiphenylamine (I) by electroreducing a 1 M solution of a sodium salt of 4-nitrosodiphenylamine (II) in a 5-% alkali solution are found. The electroreduction is carried out on the copper and stainless-steel cathodes with a continuous extraction of the product into a water-immiscible solvent. Variations in the alkali concentration, current density, and temperature have no effect on the yield of I, which is almost quantitative. The current efficiency increases with the temperature and approaches 60% at 60–70°C on a copper cathode. Copper and stainless-steel cathodes and stainless-steel anodes are sufficiently stable in the 4-aminodiphenylamine electrosynthesis.