Degussa Aktiengesellschaft

Norbert Finke

Guido Stochniol

Bernd Jaeger

Thomas Haas

Christian Lettmann

Werner Burkhardt

Juergen Grunert

Monika Berweiler

Daniel Ostgard

Jorg Sauer

Ranier Lomoelder

The invention relates to a process for hydrogenating an aromatic amine that has at least one amino group bound to an aromatic nucleus with hydrogen in the presence of a supported catalyst that contains at least ruthenium as active metal. The catalyst support has a BET surface area in the range from greater than 30 m/g to less than 70 m/g and more than 50% of the pore volume of the catalyst support is formed by macropores having a pore diameter of greater than 50 nm and less than 50% are mesopores having a pore diameter of 2 to 50 nm.

Process for hydrogenating an aromatic amine in the presence of a supported ruthenium catalyst

The invention relates to a method for hydrogenation of aromatic urethanes, which contain one or more aromatic rings and one or more urethane groups bonded directly and/or indirectly to one aromatic ring or to different aromatic rings, using hydrogen in the presence of a supported catalyst, which contains ruthenium as active metal. The catalyst support of the catalyst to be used according to the invention has a BET surface ranging from larger than 30 m /g to smaller than 70 m /g and more than 50% of the pore volume of the catalyst support is represented by macropores with a pore diameter of larger than 50 nm and less than 50% is represented by mesopores with a pore diameter of 2 to 50 nm. The method is suitable in particular for hydrogenation of dibutyl 4,4&prime;-methylenedicarbanilate to dibutyl 4,4&prime;-methylenedicyclohexylcarbamate with a trans-trans isomer content of <30%, preferably of <20%, particularly preferably of 5 to 15%.

Method for hydrogenation of aromatic urethanes in the presence of a supported ruthenium catalyst

Process for the preparation of isophorone diamine from isophorone nitrile, isophorone nitrilimine or mixtures containing isophorone nitrile and/or isophorone nitrilimine by hydrogenation through to amine in the presence of at least ammonia, hydrogen and a formed Raney hydrogenation catalyst based on cobalt, nickel, copper and/or iron, wherein the Raney catalyst is present in the form of hollow bodies.

Process for the preparation of 3-aminomethyl-3,5,5-trimethylcyclohexylamine

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Oer-Erkenschwick, Germany

Norbert Finke