Preparation of cyclic amines

摘要

A process for the preparation of a phenyl amine which may be substituted by alkyl or cycloalkyl in which the corresponding cyolohexylamine is reduced at temperatures of 150 DEG to 300 DEG C. and pressures of 0.01 to 50 bar in the presence of a heterogeneous dehydrogenation catalyst consisting essentially of palladium or a palladium/platinum mixture supported on carrier consisting of the oxides of rare earth metals and and metals of Group IVb of the Periodic Table of Elements, with the proviso that the palladium/platinum mixture may also be supported on an alumina carrier. The cyclohexylamine reactant can be advantageously prepared by reacting the corresponding phenol with ammonia and hydrogen at 100 DEG to 250 DEG C. in the presence of the same heterogeneous catalyst as a preliminary step to provide a two stage process using the same catalyst in both stages.