Cyclohexanone

Cyclohexanone

Skeletal formula of cyclohexanone Ball-and-stick model of cyclohexanone
Identifiers
CAS Number	108-94-1 Y
3D model (JSmol)	Interactive image
ChEMBL	ChEMBL18850 Y
ChemSpider	7679 Y
ECHA InfoCard	100.003.302
KEGG	C00414 Y
PubChem CID	7967
UNII	5QOR3YM052 Y
CompTox Dashboard (EPA)	DTXSID6020359
InChI InChI=1S/C6H10O/c7-6-4-2-1-3-5-6/h1-5H2 Y Key: JHIVVAPYMSGYDF-UHFFFAOYSA-N Y InChI=1/C6H10O/c7-6-4-2-1-3-5-6/h1-5H2 Key: JHIVVAPYMSGYDF-UHFFFAOYAY
SMILES C1CCC(=O)CC1
Properties
Chemical formula	C6H10O
Molar mass	98.15 g/mol
Appearance	Colorless, liquid
Density	0.9478 g/mL, liquid
Melting point	−16.4 °C
Boiling point	155.65 °C
Solubility in water	Slightly soluble
Solubility in ethanol	Miscible
Refractive index (nD)	1.447
Viscosity	2.02 cP at 25 °C
Thermochemistry
Std molar entropy (S⦵298)	+229.03 J.K−1.mol−1
Std enthalpy of formation (ΔfH⦵298)	−270.7 kJ mol−1
Std enthalpy of combustion (ΔcH⦵298)	−3519.3 kJmol−1
Hazards
NFPA 704 (fire diamond)	1 2
Flash point	44 °C
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is YN ?) Infobox references

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 oil has an odor reminiscent of peardrop sweets as well as acetone. Over time, samples assume a yellow color due to oxidation. Cyclohexanone is slightly soluble in water (5-10 g/100 mL), but miscible with common organic solvents. Billions of kilograms are produced annually, mainly as a precursor to nylon.

Production

Cyclohexanone is produced by the oxidation of cyclohexane in air, typically using cobalt catalysts:

C₆H₁₂ + O₂ → (CH₂)₅CO + H₂O

This process co-forms cyclohexanol, and this mixture, called "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 C₆H₁₁O₂H. In some cases, purified cyclohexanol, obtained by hydration of cyclohexene, is the precursor. Alternatively, cyclohexanone can be produced by the partial hydrogenation of phenol:

C₆H₅OH + 2 H₂ → (CH₂)₅CO

This process can also be adjusted to favor the formation of cyclohexanol.

Laboratory methods

Cyclohexanone can be prepared from cyclohexanol by oxidation with chromic oxide.

Uses

The great majority of cyclohexanone is consumed in the production of precursors to Nylon 6,6 and Nylon 6. About half of the world's supply is converted to adipic acid, one of two precursors for nylon 6,6. For this application, the KA oil (see above) is oxidized with nitric acid. The other half of the cyclohexanone supply is converted to the oxime. In the presence of sulfuric acid catalyst, the oxime rearranges to caprolactam, a precursor to nylon 6:

Safety

Like cyclohexanol, cyclohexanone is not carcinogenic and is only moderately toxic, with a TLV of 25 ppm for the vapor. It is an irritant.

A recent study of plastic tubing used in medical procedures that circulate blood outside the body suggests a link between this compound and decreased heart function, swelling, loss of taste and short term memory loss.