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Dimedone

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Dimedone
Names
IUPAC name
5,5-Dimethylcyclohexane-1,3-dione
Other names
Cyclomethone,
5,5-dimethyl-1,3-cyclohexanedione,
Dimethyldihydroresorcinol,
Methone
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.004.369 Edit this at Wikidata
UNII
  • InChI=1S/C8H12O2/c1-8(2)4-6(9)3-7(10)5-8/h3-5H2,1-2H3 checkY
    Key: BADXJIPKFRBFOT-UHFFFAOYSA-N checkY
  • InChI=1/C8H12O2/c1-8(2)4-6(9)3-7(10)5-8/h3-5H2,1-2H3
    Key: BADXJIPKFRBFOT-UHFFFAOYAX
  • O=C1CC(=O)CC(C)(C)C1
Properties
C8H12O2
Molar mass 140.17968
Appearance Yellow crystals
Melting point 147 to 150 °C (297 to 302 °F; 420 to 423 K) (decomposes)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
checkY verify (what is checkY☒N ?)

Dimedone is a cyclic diketone used in organic chemistry to determine whether a compound contains an aldehyde group. Cyclohexanediones in general can be used as catalysts in the formation of transition-metal complexes. Other uses include applications in colorimetry, crystallography, luminescence and spectrophotometric analysis. It can also be used for chemistry involving organic compounds of low electrical resistance.

Synthesis

Dimedone is prepared from mesityl oxide and diethyl malonate.[1]

Physical properties

Dimedone usually comes in the form of white crystals. It is stable under ambient conditions and soluble in water, as well as ethanol and methanol. It has a melting point range of 147–150 °C (420–423 K).

Tautomerism

Dimedone is in equilibrium with its tautomer in solution — in a 2:1 keto to enol ratio in chloroform.[2]

Diagram of tautomeric equilibrium of dimedone

Crystalline dimedone contains chains of molecules, in the enol form, linked by hydrogen bonds:[3]

Ball-and-stick model of a hydrogen-bonded dimedone chain, as found in the crystal structure

References

  1. ^ R. L. Shriner and H. R. Todd (1935). "5,5-dimethyl-1,3-cyclohexanedione". Organic Syntheses. 15: 16. doi:10.1002/0471264180.os015.06.
  2. ^ Clayden, Jonathan; Greeves, Nick; Warren, Stuart; Wothers, Peter (2001). Organic Chemistry (1st ed.). Oxford University Press. p. 532. ISBN 978-0-19-850346-0.
  3. ^ M. Bolte and M. Scholtyssik (October 1997). "Dimedone at 133K". Acta Crystallogr. C. 53 (10): IUC9700013. doi:10.1107/S0108270197099423.