Water → 3-Bromo-5-methylbenzoic acid

HRID 1771751Notes

Reaction equation

HRID 1771751 reaction equation
[Br:1][C:2]1[CH:7]=[C:6]([CH3:8])[CH:5]=[C:4]([CH3:9])[CH:3]=1.[O-:10][Mn](=O)(=O)=O.[K+].[OH2:16]>N1C=CC=CC=1>[Br:1][C:2]1[CH:7]=[C:6]([CH:5]=[C:4]([CH3:9])[CH:3]=1)[C:8]([OH:10])=[O:16]

Participants

5

Reactant 3

HCID 962WaterHCID 136357Benzene, 1-bromo-3,5-dimethyl-HCID 516875Potassium Permanganate

Product 1

HCID 34331273-Bromo-5-methylbenzoic acidYield 29%

Reagents, catalysts & solvents 1

HCID 1049PyridineSolvent

Conditions

Temperature
80 °C

Procedure

1-bromo-3,5-dimethylbenzene (15 g, 81 mmol, 1.0 eq) in a mixture of pyridine (133 mL) and H2O (83 mL) was heated to 80° C. KMnO4 (25.6 g, 162 mmol, 2.0 eq) was added in portions over 45 min. After the addition was completed, heating was continued at 80° C. for 1.5 h. The hot solution was then filtered, and the filtrate was acidified by addition of concentrated hydrochloric acid. The aqueous solution was extracted with EtOAc and the combined organic extracts washed with water and brine, dried (Na2SO4), filtered and evaporated in vacuo. The residue was purified by column chromatography (CH2Cl2: MeOH, 80:1 to 40:1) to give the title compound as a white solid (5.2 g, 29%)

Workup

  1. additionAfter the addition
  2. temperatureheating
  3. filtrationThe hot solution was then filtered
  4. additionthe filtrate was acidified by addition of concentrated hydrochloric acid
  5. extractionThe aqueous solution was extracted with EtOAc
  6. washthe combined organic extracts washed with water and brine
  7. dry with materialdried (Na2SO4)
  8. filtrationfiltered
  9. customevaporated in vacuo
  10. customThe residue was purified by column chromatography (CH2Cl2: MeOH, 80:1 to 40:1)

Sources & evidence

ORD record
ord-4267c743872e486c8b0a44f8f2ed10c4
Source dataset
uspto-grants-2016_02
Patent number
US09249085B2

Reaction notes

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