Method of preparation of 4-aminodiphenylamine
AssigneeDuslo, A.S. Sala
InventorsEmanuel Be{haeck over (s)}ka, Peter Toman, Karol Fiedler, Milan Hronec, Jozef Pint{dot over (e)}r
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Abstract
A method of preparing 4-aminodiphylamine through an intermediate preparation of 4-nitrodiphenylamine and/or 4-nitrosodiphenylamine and/or their salts by reaction of aniline with nitobenzene in a liquid medium at a temperature of 50 to 130° C., under normal or reduced pressure, in an inert atmosphere or in the presence of air oxygen, with subsequent hydrogenation of an intermediate of 4-nitrodiphenylamine and/or nitrosodiphenylamine and side products, and by isolation of 4-aminodiphenylamine and the side products of unconverted raw materials.
Claims16
Method of preparation of 4-aminodiphenylamine through an intermediate preparation of 4-nitrodiphenylamine and/or 4-nitrosodiphenylamine and/or their salts by the reaction of aniline with nitrobenzene in a liquid medium at a temperature of 50 to 130° C., under normal or reduced pressure, in an inert atmosphere or in the presence of air oxygen, with subsequent hydrogenation of the intermediate of 4-nitrodiphenylamine or 4-nitrosodiphenylamine and side products, and by isolation of 4-aminodiphenylamine and the side products and recirculation of unconverted raw materials, characterized in that the reaction of aniline with nitrobenzene is performed in a reaction system, consisting of a solution of salts of true zwitterions with hydroxides of a general formula
- HO−(R1R2R3)N+—CHR4—(CH2)x—Y/Z+
- where
- R1 and R2 means methyl, ethyl, or C3-C12 linear alkyl group,
- R3 means methyl, ethyl, phenyl, benzyl,
- R4 means hydrogen or methyl,
- x means an integer of 0 to 5,
- Y− means CO2−, SO3− and
- Z+ means a cation of an alkali metal Na, K, Cs, or a tetrasubstituted quaternary ammonium cation, or their mutual combination, wherein the amounts of both the zwitterion salt and hydroxide are at last equimolar amounts related to the amount of nitrobenzene taken up in the reaction wherein 4-nitrosodiphenylamine and/or 4-nitrodiphenylamine arise, which yield after hydrogenation 4-AFDA, and after the reaction at least a half of the reaction system is recycled.
A method of preparing 4-aminodiphenylamine comprising the steps of:
- reacting aniline with nitrobenzene in a liquid medium at a temperature of 50 to 130° C. in the presence of salts of true zwitterions with hydroxides of a general formula:
- HO−/(R1R2R3)N+—CHR4—(CH2)x—Y/Z+
- wherein
- R1 and R2 is a methyl, ethyl, or C3-C12 linear alkyl group,
- R3 is methyl, ethyl, phenyl, or benzyl,
- R4 is hydrogen or methyl,
- x is an integer between 0 to 5,
- Y− is CO2− or SO3− and
- Z+ is one or more of Na, K, Cs, or a tetrasubstituted quaternary ammonium cation, wherein the amount of the zwitterion salt and the hydroxide are at last equimolar to the amount of nitrobenzene consumed in the reaction, and wherein unreacted aniline and nitrobenzene is recirculated to provide a reaction mixture comprising 4-nitrodiphenylamine and/or 4-nitrosodiphenylamine and/or their salts and side products;
- hydrogenating the reaction mixture to provide a hydrogenated reaction mixture;
- isolating the 4-aminodiphenylamine and the side products from the hydrogenated reaction mixture.
Dependencies are inferred from the claim text.