Cyclohexanone oxime

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Not to be confused with caprolactam.
Cyclohexanone oxime
Structure of cyclohexanone oxime.png
CAS number 100-64-1
PubChem 7517
ChemSpider 7236
ChEMBL CHEMBL103371714
Jmol-3D images Image 1
Molecular formula C6H11NO
Molar mass 113.16 g/mol
Appearance Gray crystals
Melting point 88 to 91 °C (190 to 196 °F; 361 to 364 K)
Boiling point 204 to 206 °C (399 to 403 °F; 477 to 479 K)
Solubility in water insoluble
EU classification Not available
S-phrases S24/25
Flash point 110 °C (230 °F; 383 K)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Cyclohexanone oxime is an organic compound containing the functional group oxime. This compound is usually not isolated as a pure compound as it is unstable when pure. However, it is an important intermediate in the production of nylon 6, a widely used polymer. It should not be confused with caprolactam, which is an isomer of the compound.


Cyclohexanone oxime can be prepared from the condensation reaction between cyclohexanone and hydroxylamine, in the presence of an acid catalyst.

Alternatively, another industrial route involves the reaction of cyclohexane with nitrosyl chloride, which is a free radical reaction. This method is advantageous as cyclohexane is much cheaper than cyclohexanone.


The most famous and important reaction is that cyclohexanone oxime undergoes Beckmann rearrangement when heated with an acid catalyst, yielding ε-caprolactam:

Beckmann rearrangement of cyclohexanone oxime.png

As the compound contains the oxime group, it undergoes usual reactions of an oxime. For example, reducing cyclohexanone oxime by sodium amalgam gives cyclohexylamine. It can also be hydrolyzed with acetic acid to give cyclohexanone again.