Water → 2,6-Dimethylterephthalic acid

HRID 345224Notes

Reaction equation

HRID 345224 reaction equation
[CH3:1][C:2]1[CH:10]=[C:9]([CH3:11])[CH:8]=[C:7]([CH3:12])[C:3]=1[C:4]([OH:6])=[O:5].[OH-:13].[Na+].[Mn]([O-])(=O)(=O)=O.[K+].S(=O)(=O)(O)O.S(=O)(O)[O-].[Na+].[OH2:31]>>[CH3:1][C:2]1[CH:10]=[C:9]([C:11]([OH:31])=[O:13])[CH:8]=[C:7]([CH3:12])[C:3]=1[C:4]([OH:6])=[O:5]

Participants

7

Reactant 6

HCID 962WaterHCID 1118Sulfuric AcidHCID 101942,4,6-Trimethylbenzoic acidHCID 14798Sodium HydroxideHCID 516875Potassium PermanganateHCID 23665763Sodium Bisulfite

Product 1

HCID 2465942,6-Dimethylterephthalic acidYield 89%

Conditions

Temperature
0 °C

Procedure

2,4,6-Trimethylbenzoic acid (mesitoic acid) (10 g, 61 mmol) was suspended in 150 mL of water, and the mixture cooled to 0° C. Sodium hydroxide pellets (7.31 g, 0.18 mol) were gradually added, followed by addition of potassium permanganate (4×7.2 g, 0.18 mol) at four intervals of 30 minutes. The mixture was stirred at room temperature for 2 hours, then heated on a steam bath for 15-30 minutes. Sulfuric acid (200 mL, 9 mol) was added, then sodium bisulfite was carefully and gradually added at 0° C. The precipitated white solid was filtered and then dissolved in 5 N ammonium hydroxide. The solution was washed with diethyl ether, then gradually treated dropwise with concentrated sulfuric acid to precipitate the product. Filtration, followed by washing with hot water (4×) and petroleum ether (3×), recrystallization (methanol-water), and drying at high vacuum gave 10.5 g (89%) of the product as a white solid, m.p. >300° C. (ref. W. A. Noyes, Amer. Chem. J., 20, 789 (1898)).

Workup

  1. additionwere gradually added
  2. temperatureheated on a steam bath for 15-30 minutes
  3. additiongradually added at 0° C
  4. filtrationThe precipitated white solid was filtered
  5. dissolutiondissolved in 5 N ammonium hydroxide
  6. washThe solution was washed with diethyl ether
  7. additiongradually treated dropwise with concentrated sulfuric acid
  8. customto precipitate the product
  9. filtrationFiltration
  10. washby washing with hot water (4×) and petroleum ether (3×), recrystallization (methanol-water)
  11. customdrying at high vacuum

Sources & evidence

ORD record
ord-a82fbcc39feb45838229b40acec782c3
Source dataset
uspto-grants-1991_10
Patent number
US05055451

Reaction notes

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