PURIFICATION OF P-NITRODIPHENYLAMINE

摘要

PURPOSE:To obtain the titled compound useful as a synthetic intermediate for N-alkyl-N'-phenyl-p-phenylenediamine, from a crude p-nitrodiphenylamine produced by the use of a copper-based catalyst, by treating the crude compound with an aqueous solution of a mineral acid and recrystallizing the product. CONSTITUTION:Crude p-nitrodiphenylamine is produced by reacting a p- halonitrobenzene with aniline using a copper-based catalyst such as copper oxide in the presence of a neutralizing agent (e.g. potassium carbonate) and a solubilizing agent (e.g. polyether). The crude product is washed with an aqueous solution of a mineral acid (e.g. sulfuric acid) having a concentration of 0.2-20wt% in an aromatic hydrocarbon or aliphatic hydrocarbon solvent preferably substituted with one or more halogen atoms. The cleaned compound is recrystallized from the above solvent to obtain a purified p-nitrodiphenylamine having high quality.