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.

Synthesis
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. It is also obtained by reductive amination of cyclohexanone with ammonia or cyclohexylamine. 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.

Applications
Dicyclohexylamine has applications that are similar to those of cyclohexylamine, namely the production of:
 * antioxidants in rubber and plastics
 * vulcanization accelerators for rubber
 * corrosion inhibitors in steam pipes and boilers
 * agrochemicals
 * textile chemicals
 * catalysts for flexible polyurethane foams