Oxygen → 2,3-Dimethyl-2,5-cyclohexadiene-1,4-dione

HRID 727482

Reaction equation

HRID 727482 reaction equation
O=O.S(=O)(=O)(O)O.[CH3:8][C:9]1[C:15]([CH3:16])=[C:14]([OH:17])[CH:13]=[CH:12][C:10]=1[OH:11]>C(O)(=O)C>[CH3:16][C:15]1[C:14](=[O:17])[CH:13]=[CH:12][C:10](=[O:11])[C:9]=1[CH3:8]

Participants

5

Reactant 3

HCID 977Oxygen2×HCID 1118Sulfuric AcidHCID 691002,3-Dimethylhydroquinone

Product 1

HCID 106882,3-Dimethyl-2,5-cyclohexadiene-1,4-dioneYield 95.5%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent2×

Conditions

Temperature
40 °C

Procedure

Oxygen was passed into a solution of 0.68 g (2 mmol) of iron 5,14-dihydrodibenzo[b,i][5,9,14,18]tetraaza[14]annulene and 0.5 g of concentrated sulfuric acid in 150 ml of 85% by weight aqueous acetic acid and, during this, a solution of 12.4 g (100 mmol) of 2,3-dimethylhydroquinone in 75 ml of 85% by weight acetic acid was added dropwise while stirring vigorously at 40° C. After oxygen uptake ceased, the mixture was subjected to a steam distillation. The distillate was extracted with tert-butyl methyl ether. The organic phase was shaken with aqueous sodium bicarbonate solution and then with water, separated from the aqueous phase, dried over magnesium sulfate, filtered and evaporated to dryness to yield 13.0 g (95%) of 2,3-dimethylbenzoquinone in the form of a yellow powder. Melting point 56°-57° C.

Workup

  1. distillationthe mixture was subjected to a steam distillation
  2. extractionThe distillate was extracted with tert-butyl methyl ether
  3. stirringThe organic phase was shaken with aqueous sodium bicarbonate solution
  4. customwith water, separated from the aqueous phase
  5. dry with materialdried over magnesium sulfate
  6. filtrationfiltered
  7. customevaporated to dryness

Sources & evidence

ORD record
ord-5cb87e9728a447c39164768f0a296fe5
Source dataset
uspto-grants-1998_01
Patent number
US05712416

Linked notes

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