Cyclohexanol is the organic compound with the

formula In science, a formula is a concise way of expressing information symbolically, as in a mathematical formula or a ''chemical formula''. The informal use of the term ''formula'' in science refers to the general construct of a relationship betwee ...

HOCH(CH₂)₅. The molecule is related to

cyclohexane Cyclohexane is a cycloalkane with the molecular formula . Cyclohexane is non-polar. Cyclohexane is a colorless, flammable liquid with a distinctive detergent-like odor, reminiscent of cleaning products (in which it is sometimes used). Cyclohexan ...

by replacement of one hydrogen atom by a

hydroxyl group In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy g ...

. This compound exists as a deliquescent colorless solid with a camphor-like odor, which, when very pure, melts near room temperature. Billions of kilograms are produced annually, mainly as a precursor to nylon.Michael Tuttle Musser "Cyclohexanol and Cyclohexanone" in Ullmann's Encyclopedia of Industrial Chemistry, Wiley-VCH, Weinheim, 2005.

Production

Cyclohexanol is produced by the oxidation of

in air, typically using cobalt catalysts: :C₆H₁₂ + 1/2 O₂ → C₆H₁₁OH This process co-forms

cyclohexanone Cyclohexanone is the organic compound with the formula (CH2)5CO. The molecule consists of six-carbon cyclic molecule with a ketone functional group. This colorless oily liquid has an odor reminiscent of acetone. Over time, samples of cyclohexan ...

, and this mixture ("KA oil" for ketone-alcohol oil) is the main feedstock for the production of adipic acid. The oxidation involves radicals and the intermediacy of the

hydroperoxide Hydroperoxides or peroxols are Chemical compound, compounds containing the hydroperoxide functional group (ROOH). If the R is organic, the compounds are called organic hydroperoxides. Such compounds are a subset of organic peroxides, which have t ...

C₆H₁₁O₂H. Alternatively, cyclohexanol can be produced by the hydrogenation of phenol: :C₆H₅OH + 3 H₂ → C₆H₁₁OH This process can also be adjusted to favor the formation of cyclohexanone.

Basic reactions

Cyclohexanol undergoes the main reactions expected for a secondary alcohol. Oxidation gives

, which is converted on a large scale in industry to the oxime, a precursor to caprolactam. As a laboratory exercise, this oxidation can be effected with chromic acid. Esterification affords the commercially useful derivatives dicyclohexyladipate and dicyclohexylphthalate, which are used as plasticizers. Heating in the presence of acid catalysts converts cyclohexanol to cyclohexene.

Structure

Cyclohexanol has at least two solid phases. One of them is a plastic crystal.

Applications

As indicated above, cyclohexanol is an important feedstock in the polymer industry, firstly as a precursor to nylons, but also to various plasticizers. Small amounts are used as a solvent.

Safety

Cyclohexanol is moderately toxic: the TLV for the vapor for 8 h is 50 ppm. The IDLH concentration is set at 400 ppm, based on studies on the acute oral toxicity in animals. Few studies have been done on its carcinogenicity, but one study on rats found it to have

co-carcinogenic A co-carcinogen is a chemical that promotes the effects of a carcinogen in the production of cancer. Usually, the term is used to refer to chemicals that are not carcinogenic on their own, such that an equivalent amount of the chemical is ins ...

effects.
Lucrecia Márquez-Rosado, Cristina Trejo-Solís 2, María del Pilar Cabrales-Romero, Evelia Arce-Popoca, Adolfo Sierra-Santoyo, Leticia Alemán-Lazarini, Samia Fatel-Fazenda, Claudia E. Carrasco-Legleu, Saúl Villa-Treviño, "Co-carcinogenic effect of cyclohexanol on the development of preneoplastic lesions in a rat hepatocarcinogenesis model", ''Molecular Carcinogenesis'', Vol. 46, No. 7, Pages 524 - 533, March 2007.

References

{{Chemical agents Cyclohexyl compounds Cycloalkanols Nerve agent precursors