3-(4-Methoxyphenoxy)benzoic acid → 3-(4-Hydroxyphenoxy)benzoic acid

HRID 1709018Notes

Reaction equation

HRID 1709018 reaction equation
C[O:2][C:3]1[CH:18]=[CH:17][C:6]([O:7][C:8]2[CH:9]=[C:10]([CH:14]=[CH:15][CH:16]=2)[C:11]([OH:13])=[O:12])=[CH:5][CH:4]=1>C(O)(=O)C.Br.C(OCC)(=O)C.CO>[OH:2][C:3]1[CH:18]=[CH:17][C:6]([O:7][C:8]2[CH:9]=[C:10]([CH:14]=[CH:15][CH:16]=2)[C:11]([OH:13])=[O:12])=[CH:5][CH:4]=1

Participants

6

Reactant 1

HCID 6185083-(4-Methoxyphenoxy)benzoic acid

Product 1

HCID 1618523-(4-Hydroxyphenoxy)benzoic acid

Reagents, catalysts & solvents 4

HCID 176Acetic AcidSolventHCID 260Hydrogen BromideSolventHCID 887MethanolSolventHCID 8857Ethyl AcetateSolvent

Procedure

An amount of 3-(4'-methoxyphenoxy)benzoic acid (40.7 g, 0.167 mole) was dissolved in 200 ml of acetic acid to which 150 ml of a 48 percent solution of hydrogen bromide (HBr) was added (Aldrich Chemical Company). The reaction mixture was heated to reflux under nitrogen for 14.5 hours. The cooled reaction mixture was then diluted with 400 ml of ethyl acetate (EtOAc), washed with saturated NaCl (3×150 ml), dried with MgSO4, filtered, and solvent evaporated to afford a dark brown solid. The crude product was dissolved in methanol, treated with activated carbon, filtered through a celite pad, and evaporated. Recrystallization of the product (1:1 acetic acid/water) gave 3-(4'-hydroxyphenoxy)benzoic acid as tan crystals with a m.p. of 163° C. to 166° C.

Workup

  1. additionwas added (Aldrich Chemical Company)
  2. temperatureThe reaction mixture was heated
  3. temperatureto reflux under nitrogen for 14.5 hours
  4. customThe cooled reaction mixture
  5. washwashed with saturated NaCl (3×150 ml)
  6. dry with materialdried with MgSO4
  7. filtrationfiltered
  8. customsolvent evaporated
  9. customto afford a dark brown solid
  10. additiontreated with activated carbon
  11. filtrationfiltered through a celite pad
  12. customevaporated
  13. customRecrystallization of the product (1:1 acetic acid/water)

Sources & evidence

ORD record
ord-ec58beee0adb4d38983eac0633a50038
Source dataset
uspto-grants-1990_08
Patent number
US04946926

Reaction notes

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