Method of preparing 4-aminodiphenylamine

A method of producing substituted derivatives of 4-aminodiphenylamine (4-ADPA) comprising:

• a) bringing substituted aniline derivatives and nitrobenzene into reactive contact in a suitable solvent system;
• b) reacting the substituted aniline derivatives and nitrobenzene in a confined zone at a suitable temperature, and in the presence of a suitable base and controlled amount of protic material to produce one or more 4-ADPA intermediates;
• and
• c) reducing the 4-ADPA intermediates under conditions which produce substituted derivatives of 4-ADPA.

A method of producing substituted derivatives of alkylated p-phenylenediamines comprising:

• a) bringing substituted aniline derivatives and nitrobenzene into reactive contact in a suitable solvent system;
• b) reacting the substituted aniline derivatives and nitrobenzene in a confined zone at a suitable temperature, and in the presence of a suitable base and controlled amount of protic material to produce one or more 4-ADPA intermediates;
• c) reducing the 4-ADPA intermediates to produce substituted derivatives of 4-ADPA;
• and
• d) reductively alkylating the substituted derivatives of 4-ADPA of Step (c).

A method of producing one or more 4-ADPA intermediates comprising:

• a) bringing aniline or substituted aniline derivatives and nitrobenzene into reactive contact in a suitable solvent system;
• and
• b) reacting the aniline or substituted aniline derivatives and nitrobenzene in a confined zone at a suitable temperature, and in the presence of a suitable base and a controlled amount of protic material to produce one or more 4-ADPA intermediates,
• wherein said base is combined with said aniline or substituted aniline derivative to form a mixture and said nitrobenzene is added to said mixture at a controlled rate.

A method of producing one or more 4-ADPA intermediates comprising:

• a) bringing aniline or substituted aniline derivatives and nitrobenzene into reactive contact in a suitable solvent system;
• and
• b) reacting the aniline or substituted aniline derivatives and nitrobenzene in a confined zone at a suitable temperature, and in the presence of a suitable base and a controlled amount of protic material to produce one or more 4-ADPA intermediates;
• wherein said suitable solvent is aniline, said protic material is water and the amount of protic material present at the beginning of the reaction is up to about 9.8 volume % water based on the total volume of the reaction mixture.