Dimedon

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Structural formula
Keto form Enol form
Keto form (left) and enol form (right)
General
Surname Dimedon
other names
  • 5,5-dimethylcyclohexane-1,3-dione
  • Methone
  • 5,5-dimethyldihydroresorcinol
Molecular formula C 8 H 12 O 2
Brief description

white crystals

External identifiers / databases
CAS number 126-81-8
EC number 204-804-4
ECHA InfoCard 100.004.369
PubChem 31358
Wikidata Q418261
properties
Molar mass 140.18 g mol −1
Physical state

firmly

Melting point

146-148 ° C

safety instructions
GHS labeling of hazardous substances
no GHS pictograms
H and P phrases H: no H-phrases
P: no P-phrases
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Dimedon is used in organic analysis to identify and separate aldehydes (including formaldehyde ). It forms white crystals.

presentation

The presentation is achieved by deprotonation of diethyl malonate in a sodium ethoxide . Mesityloxide is added in a slight deficit . After prolonged heating, it is neutralized, with the dimedon separating out as an oil or even in crystalline form.

properties

Dimedon stands in solution in a tautomeric equilibrium - in the ratio 2: 1 of the keto / enol form in chloroform .

Tautomeric equilibrium of the Dimedo

Individual evidence

  1. ↑ a b R. L. Shriner, HR Todd: 5,5-Dimethylcyclohexane-1,3-dione In: Organic Syntheses . 15, 1935, p. 14, doi : 10.15227 / orgsyn.015.0014 ; Coll. Vol. 2, 1943, p. 200 ( PDF ).
  2. ↑ a b c data sheet 5,5-dimethyl-1,3-cyclohexanedione from Sigma-Aldrich , accessed on May 12, 2017 ( PDF ).
  3. ↑ Jonathan Clayden, Nick Greeves, Stuart Warren, Peter Wothers: Organic Chemistry , 2001, Oxford University Press, ISBN 0-19-850346-6 , p. 532: Formation and reactions of enols and enolates.
  4. ↑ M. Bolte, M. Scholtyssik: Dimedone at 133K , in: Acta Cryst. , 1997 , C53 , IUC9700013; doi : 10.1107 / S0108270197099423 .