Cyclohexanone is the organiccompound with the formula(CH2)5CO. The molecule consists of six-carbon cyclic molecule with ketone a functional group. This colorless oil has an odor reminiscent of peardrop sweetsas well as acetone.Over time, samples assume a yellow color due to oxidation. Cyclohexanone isslightly soluble in water and miscible with common organic solvents. Billionsof kilograms are produced annually, mainly as a precursor to nylon.
Cyclohexanone is produced by theoxidation of cyclohexane in air, typically using cobaltcatalysts:
C6H12 + O2 → (CH2)5CO + H2O
This process co-forms cyclohexanol,and this mixture, called "KA Oil" for ketone-alcohol oil, is the mainfeedstock for the production of adipic acid.The oxidation involves radicals and the intermediacy of the hydroperoxide C6H11O2H. Insome 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 adjustedto favor the formation of cyclohexanol.
Cyclohexanone can be preparedfrom cyclohexanol by oxidation with chromiumtrioxide (Jones oxidation). An alternative methodutilizes the safer and more readily available oxidant sodium hypochlorite.
The great majority ofcyclohexanone 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 thecyclohexanone supply is converted to cyclohexanone oxime. In the presence of sulfuric acidcatalyst,the oxime rearranges to caprolactam,a precursor to nylon 6:
Like cyclohexanol,cyclohexanone is not carcinogenic and is only moderately toxic, with a TLV of 25 ppm for the vapor. It is anirritant.
A recent study of plastic tubingused in medical procedures that circulate blood outside the body suggests alink between this compound and decreased heart function, swelling, loss oftaste and short term memory loss.