Process for preparing diphenylamines
AssigneeBayer Aktiengesellschaft
InventorsHermann-Dieter Krall, Oskar Weissel, Hans-Helmut Schwarz
Life of this patent
Estimating the term…
Abstract
Diphenylamines having the formula: ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or different and are hydrogen, alkyl with up to 4 C atoms or alkoxy with up to 4 C atoms, Are prepared by catalytically dehydrogenating the corresponding wholly or partially hydrogenated diphenylamines. The catalyst used is a nickel/chromium catalyst containing manganese and/or aluminum and/or copper and/or sulphates of the alkali metals or alkaline earth metals.
Claims18
In a process for preparing a diphenylamine having the formula ##STR4## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are the same or different and are hydrogen, alkyl containing 1 to 4 carbon atoms or alkoxy containing 1 to 4 carbon atoms
- by catalytic dehydrogenation of a dicyclohexylamine, N-cyclohexylidene-cyclohexylamine, N-cyclohexyl-aniline or N-cyclohexylidene-aniline in the presence of a nickel/chromium catalyst the improvement which comprises employing as the nickel/chromium catalyst one which contains at least one member of the group manganese, aluminum and copper.
Dependencies are inferred from the claim text.