Water → HCID 54498861, compound

HRID 259930Notes

Reaction equation

HRID 259930 reaction equation
[F:1][C:2]1[CH:11]=[C:10]([CH2:12][CH2:13][CH3:14])[C:9]([O:15]C)=[CH:8][C:3]=1[C:4]([O:6]C)=[O:5].B(Br)(Br)Br.[OH-].[Na+].O>C(Cl)Cl>[F:1][C:2]1[CH:11]=[C:10]([CH2:12][CH2:13][CH3:14])[C:9]([OH:15])=[CH:8][C:3]=1[C:4]([OH:6])=[O:5]

Participants

6

Reactant 4

HCID 962WaterHCID 14798Sodium HydroxideHCID 25134Boron tribromideHCID 53747526HCID 53747526, compound

Product 1

HCID 54498861HCID 54498861, compoundYield 97.7%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent2×

Conditions

Temperature
-70 °C

Procedure

Methyl 2-fluoro-5-methoxy-4-propylbenzoate (1.27 g, 5.63 mmol) was dissolved in CH2Cl2 (20 mL) and cooled to -70° C. Boron tribromide (1.64 mL, 16.9 mmol) was added and the temperature was slowly raised to 0° C. during 4.5 h. Methylene chloride (20 mL) and 2M NaOH (25 mL) were added and the mixture was stirred overnight at room temperature. Water (20 mL) was added, the phases separated and the aqueous phase was extracted with CH2Cl2 (20 mL) and acidified to pH 1 by concentrated HCl thus precipitating the acid. Ethyl acetate (50 mL) was added to the mixture and the phases separated. The aqueous phase was extracted by additional EtOAc (50 mL) and the combined organic phases were washed with brine (20 mL), dried (MgSO4) and evaporated yielding 2-fluoro-5-hydroxy-4-propylbenzoic acid (1.09 g) Mp: 134.5°-135.5° C. 1H NMR (DMSO-d6): δ12.88 (br, 1H), 9.57 (br, 1H), 7.23 (d, J=6.5 Hz, 1H), 6.96 (d, J=11.6 Hz), 2.48 (t, J=7.5 Hz, 2H), 1.53 (m, J=7.5 Hz, 2H), 0.87 (t, J=7.4HZ, 3H). 13C NMR (DMSO-d6): δ164.96 (d, J=3 Hz), 154.38 (d, J=248 Hz), 150.84 (d, J=2 Hz), 135.82 (d, J=7 Hz), 117.44 (d, J=24 Hz), 116.28 (d, J=11 Hz), 116.22, 31.38, 21.79, 13.65. MS (EI, 70 eV): m/z (rel. int) 198 (M+, 38).

Workup

  1. temperaturethe temperature was slowly raised to 0° C. during 4.5 h
  2. customthe phases separated
  3. extractionthe aqueous phase was extracted with CH2Cl2 (20 mL)
  4. customthus precipitating the acid
  5. additionEthyl acetate (50 mL) was added to the mixture
  6. customthe phases separated
  7. extractionThe aqueous phase was extracted by additional EtOAc (50 mL)
  8. washthe combined organic phases were washed with brine (20 mL)
  9. dry with materialdried (MgSO4)
  10. customevaporated

Sources & evidence

ORD record
ord-894733a7bbe248208335cfa442985932
Source dataset
uspto-grants-1996_06
Patent number
US05523475

Reaction notes

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