Toluene → 2-Methylbenzoic acid

HRID 1266632Notes

Reaction equation

HRID 1266632 reaction equation
F[C:2](F)(F)[C:3]([OH:5])=[O:4].[C:8]1(C)[CH:13]=[CH:12][CH:11]=[CH:10][CH:9]=1>O>[CH3:11][C:10]1[CH:9]=[CH:8][CH:13]=[CH:12][C:2]=1[C:3]([OH:5])=[O:4]

Participants

4

Conditions

Temperature
53 °C

Procedure

A mixture of K2S2O8 (1.35 g), trifluoroacetic acid (5 mL), 0.083 mL of a catalyst solution as prepared in Example 3(a) above, and toluene (5 mL) was stirred under CO (1 atm) at 53° C. (oil bath) for 16 hours. After the reaction was quenched with water, the unreacted toluene was removed with an air flow over the liquid phase. Ether (20 mL) and chlorobenzene (internal standard; 0.15 mL) were added. After vigorously stirring the mixture for 5-10 minutes, the ethereal phase was analyzed by GC-MS. The GC yield of toluic acid was 260 mg (TON=58, assuming that the Rh oxide used to prepare the catalyst contained 5 molecules of water per each Rh2O3 unit). The ether layer was separated, and the aqueous layer was extracted with ether. The combined ether solutions were evaporated to dryness to give solid toluic acid which was purified by vacuum sublimation. The yield of the purified toluic acid (1H NMR: 95% p-isomer) was 222 mg.

Workup

  1. customAfter the reaction was quenched with water
  2. customthe unreacted toluene was removed with an air flow over the liquid phase
  3. additionEther (20 mL) and chlorobenzene (internal standard; 0.15 mL) were added
  4. stirringAfter vigorously stirring the mixture for 5-10 minutes
  5. customto prepare the catalyst
  6. customThe ether layer was separated
  7. extractionthe aqueous layer was extracted with ether
  8. customThe combined ether solutions were evaporated to dryness

Sources & evidence

ORD record
ord-f8883c25e7c54ba9980fc50cba253381
Source dataset
uspto-grants-2003_04
Patent number
US06548698B1

Reaction notes

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