Catalytic hydrogenation of organic nitrogenous carbon compounds to amines

Abstract

Abstract A process for the hydrogenation of aromatic amino compounds and acyclic and carbocyclic compounds containing nitrogenous groups reducible to amino groups, wherein a hydrogenation of an aromatic ring to give a cycloaliphatic ring and a reduction of a nitrogenous group to give an amino group is achieved, comprises carrying out the hydrogenation in the absence of sulphur at a temperature between 40 DEG C. and 250 DEG C. under a pressure between 20 and 600 atmospheres in the liquid phase in the presence of at least one metal hydrogenation catalyst, the catalytic activity of which is impaired by sulphur, the catalyst having been sintered prior to the hydrogenation. The catalyst may contain, for example, silver, manganese, copper, iron, cobalt or nickel and may be prepared by sintering the oxide at 800 DEG C.-1,400 DEG C. and heating the sintered oxide with hydrogen at 250 DEG C.-600 DEG C. The catalyst may be supported on a carrier and promotors may be added. Aromatic amines may be hydrogenated at 200 DEG C.-250 DEG C. to give cycloaliphatic amines and other nitrogenous compounds containing, for example, nitro, nitroso, isonitroso and cyano groups may be hydrogenated at 60 DEG C.-150 DEG C. to give amino compounds. Other substituents such as aldehyde groups which are reduced and carboxylic, halogen, amino and alkoxy groups which are not reduced may also be present in the reactants. A list of suitable reactants is given. In the examples, ethylene diamine, cyclohexylamine, tolylene diamine, dimethyl hydrazine and isopropylamine are prepared.ALSO:Oxides of silver, manganese, copper, iron, cobalt or nickel are converted to the metal by sintering the oxide by heating for example, to a temperature within 20-60 DEG C. of the melting point and reducing the sintered oxide with a stream of hydrogen. Mixtures of metal oxides may be reduced after sintering to give alloys and in examples alloys of cobalt and aluminium and cobalt, nickel and aluminium are prepared.

Inventors

• 👤 Suessenguth Hermann
• 👤 Corr Hubert
• 👤 Simon Walter

Bibliographic Details