Dicyclohexylamine

Dicyclohexylamine is a secondary amine with the chemical formula HN(C6H11)2. It is a colorless liquid, although commercial samples can appear yellow. It has a fishy odor, typical for amines. It is sparingly soluble in water. As an amine, it is an organic base and useful precursor to other chemicals. Dicyclohexylamine, as a mixture with cyclohexylamine, is prepared by the catalytic hydrogenation of aniline (phenylamine), with a catalyst of ruthenium and/or palladium. This method produces mainly cyclohexylamine with little dicyclohexylamine. Better results have been reported when the catalyst is applied to a support of niobic acid and/or tantalic acid.[2] It is also obtained by reductive amination of cyclohexanone with ammonia or cyclohexylamine.[1]

Dicyclohexylamine may also be prepared by pressure hydrogenation of diphenylamine using a ruthenium catalyst, or by the reaction of cyclohexanone with cyclohexylamine in the presence of a palladium/carbon catalyst under a hydrogen pressure of about 4 mm Hg.