Cyclohexylbenzene

Cyclohexylbenzene (or phenylhexamethylene, as it was initially called) is the organic compound with the structural formula C₆H₅−C₆H₁₁. It is a derivative of benzene with a cyclohexyl substituent (C₆H₁₁). It is a colorless liquid.

Cyclohexylbenzene

Names
Preferred IUPAC name Cyclohexylbenzene
Other names Phenylcyclohexane
Identifiers
CAS Number	827-52-1 Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL3278514
ChemSpider	12674
ECHA InfoCard	100.011.429
EC Number	212-572-0
PubChem CID	13229
UNII	TRJ2SXT894 Y
CompTox Dashboard (EPA)	DTXSID3061188
InChI InChI=1S/C12H16/c1-3-7-11(8-4-1)12-9-5-2-6-10-12/h1,3-4,7-8,12H,2,5-6,9-10H2 Key: IGARGHRYKHJQSM-UHFFFAOYSA-N
SMILES C1CCC(CC1)C2=CC=CC=C2
Properties
Chemical formula	C12H16
Molar mass	160.260 g·mol−1
Appearance	Colorless liquid
Density	0.982 g/cm3
Melting point	7.3 °C (45.1 °F; 280.4 K)
Boiling point	240.1 °C (464.2 °F; 513.2 K)
Hazards
GHS labelling:
Pictograms
Signal word	Danger
Hazard statements	H302, H304, H315, H319, H410
Precautionary statements	P264, P270, P273, P280, P301+P310, P301+P312, P302+P352, P305+P351+P338, P321, P330, P331, P332+P313, P337+P313, P362, P391, P405, P501
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

History and synthesis

Cyclohexylbenzene was first obtained in 1899 by Markovnikov's student Nikolay Kirsanov (1874–1921).^[1] He used a Friedel–Crafts alkylation of benzene with cyclohexyl chloride using a catalyst such as aluminum trichloride:^[2]

C₆H₆ + C₆H₁₁Cl → C₆H₅−C₆H₁₁ + HCl

Cyclohexylbenzene is now industrially produced by the acid-catalyzed alkylation of benzene with cyclohexene.^[3][4] The process can proceed using benzene as the exclusive organic precursor. Its partial hydrogenation gives cyclohexene, which alkylates the unhydrogenated benzene.^[5]

It is also generated by the hydrodesulfurization of dibenzothiophene,^[6] and ExxonMobil took a patent in 2009 for a process based on direct hydroalkylation of two benzene molecules.^[7]

Applications

A route to phenol analogous to the cumene process begins with cyclohexylbenzene, which is oxidized to a hydroperoxide, akin to the production of cumene hydroperoxide. Via the Hock rearrangement, cyclohexylbenzene hydroperoxide cleaves to give phenol and cyclohexanone:

C₆H₅−C₆H₁₀OOH → C₆H₅OH + OC₆H₁₀

Cyclohexanone is an important precursor to some nylons.^[8][5]