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.
3D model (JSmol)
CompTox Dashboard (EPA)
|Molar mass||181.323 g·mol−1|
|Appearance||Pale yellow liquid|
|Melting point||−0.1 °C (31.8 °F; 273.0 K)|
|Boiling point||255.8 °C (492.4 °F; 529.0 K)|
|Lethal dose or concentration (LD, LC):|
LD50 (median dose)
|373 mg/kg (oral)[clarification needed]|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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.
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
- textile chemicals
- catalysts for flexible polyurethane foams
- Karsten Eller, Erhard Henkes, Roland Rossbacher, Hartmut Höke "Amines, Aliphatic". In Ullmann's Encyclopedia of Industrial Chemistry, 2000, Wiley-VCH, Weinheim. doi:10.1002/14356007.a02_001
- U.S. Patent 5322965, "Process for the preparation of a mixture of cyclohexylamine and dicyclohexylamine using a supported noble metal catalyst", Bayer AG, 21 June 1994