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AssigneeBayer Aktiengesellschaft
InventorsMichael Schelhaas, Carl Casser, Dietmar Bielefeldt, Pieter OOms, Joachim Haider, Manfred Jautelat, Christian Laue, Henry Giera
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The invention provides a process for preparing 4-aminodiphenylamine, an important starting product for synthesizing antioxidants and stabilizers in the rubber and polymer industry, by hydrogenating nitrosobenzene with hydrogen in the presence of a proton acid as catalyst and in the presence of a hydrogenating catalyst, optionally in the presence of an inert organic solvent and thermally decomposing the 4-ADPA ammonium salt produced in this way, wherein 4-ADPA is obtained. 4-aminodiphenylamine is produced in good yields and high purity by the process according to the present invention. Furthermore, no effluent is produced, which makes the process particularly economic and ecological.
A process for preparing 4-aminodiphenylamine (4-ADPA), comprising the step of hydrogenating nitrosobenzene with hydrogen in the presence of a proton acid as catalyst and in the presence of a hydrogenation catalyst, optionally in the presence of an inert organic solvent to form an 4-ADPA ammonium salt which is then thermally decomposed to obtain 4-ADPA.
Dependencies are inferred from the claim text.