Verfahren zur Herstellung von aromatischen Aminen

• Main Authors: LAGO, ANDRE, SOMMER, KNUT, LEHNER, PETER
• Format: Patent
• Language: German
• Published: 23.12.2010
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; CHEMISTRY; METALLURGY; ORGANIC CHEMISTRY

Die Erfindung betrifft ein Verfahren zur Herstellung aromatischer Amine durch Hydrierung der entsprechenden aromatischen Nitroverbindungen und anschließende Reinigung. In der Reinigung wird das jeweilige Amin zunächst mit einer wässrigen Lösung einer Base vermischt. Anschließend wird durch Zugabe eines Überschusses an Wasser eine Entmischung von organischer und wässriger Phase herbeigeführt. Preparation of aromatic amine compounds, comprises (a) hydrogenating corresponding aromatic nitro compounds in the presence of a catalyst, where water formed during the hydrogenation is separated by phase separation to obtain crude aromatic amine compounds; and (b) purifying the obtained crude aromatic amine compounds. Preparation of aromatic amine compounds, comprises (a) hydrogenating corresponding aromatic nitro compounds in the presence of a catalyst, where water formed during the hydrogenation is separated by phase separation to obtain crude aromatic amine compounds; and (b) purifying the obtained crude aromatic amine compounds in which (i) the crude aromatic amine compounds are mixed with an aqueous solution, where the used amount and the base concentration of the aqueous solution of the base are selected such that the molar ratio of the sum of all bases, added to the aromatic amine compounds, to the phenolic hydroxyl groups, contained in the aromatic amine compounds, is not greater than 10 and the molar ratio of organic component to water is greater than 10, (ii) the mixture obtained from the step (i) is mixed with water, where the weight ratio of the mixture obtained from step (i) to the water added in step (ii) is 0.05-20, and (iii) the two-phase mixture obtained from step (ii) is subsequently separated into an organic phase containing the aromatic amine compounds and an aqueous phase.