Hydrochloric Acid → 3-Bromo-5-methylbenzoic acid

HRID 564463Notes

Reaction equation

HRID 564463 reaction equation
[O-][Mn](=O)(=O)=O.[K+].[Br:7][C:8]1[CH:9]=[C:10]([CH2:15][OH:16])[CH:11]=[C:12]([CH3:14])[CH:13]=1.Cl.C(=O)(O)[O-:19].[Na+]>O.CC(C)=O>[Br:7][C:8]1[CH:9]=[C:10]([CH:11]=[C:12]([CH3:14])[CH:13]=1)[C:15]([OH:19])=[O:16]

Participants

7

Reactant 4

HCID 313Hydrochloric AcidHCID 516875Potassium PermanganateHCID 516892Sodium BicarbonateHCID 22983157(3-Bromo-5-methylphenyl)methanol

Product 1

HCID 34331273-Bromo-5-methylbenzoic acidYield 60%

Reagents, catalysts & solvents 2

HCID 180AcetoneSolventHCID 962WaterSolvent

Procedure

A solution of KMnO4 (39.3 g, 249 mmol) in water (600 mL) was added slowly to a solution of (3-bromo-5-methylphenyl)methanol (25.0 g, 124 mmol) in acetone (500 mL), then the mixture was kept at reflux for 60 min. After cooled to room temperature, the mixture was acidified with HCl (2N, 100 mL). The brown precipitate was dissolved by adding a solution of saturated sodium bicarbonate (100 mL), and then acetone was concentrated in vacuum. Ammonia (150 mL) was added. The mixture was filtered over Celite and acidified with concentrated HCl. The product was extracted with diethyl ether (3×150 mL), the combined organic phases were dried (Na2SO4) and concentrated in vacuum to obtain 16.0 g of the acid 3-bromo-5-methylbenzoic acid as white crystals (yield: 60%). 1H NMR (400 MHz, CDCl3): δ 8.05 (s, 1 H), 7.85-7.84 (m, 1 H), 7.58 (s, 1 H), 2.40 (s, 3 H).

Workup

  1. temperatureat reflux for 60 min
  2. dissolutionThe brown precipitate was dissolved
  3. concentrationacetone was concentrated in vacuum
  4. additionAmmonia (150 mL) was added
  5. filtrationThe mixture was filtered over Celite
  6. extractionThe product was extracted with diethyl ether (3×150 mL)
  7. dry with materialthe combined organic phases were dried (Na2SO4)
  8. concentrationconcentrated in vacuum

Sources & evidence

ORD record
ord-deaaba6263d9471d9139481b6c0b0a01
Source dataset
uspto-grants-2011_11
Patent number
US08067408B2

Reaction notes

Loading…