Allyl bromide → Methyl 2-hydroxy-4-[(prop-2-en-1-yl)oxy]benzoate

HRID 29643

Reaction equation

HRID 29643 reaction equation
[CH3:1][O:2][C:3](=[O:12])[C:4]1[CH:9]=[CH:8][C:7]([OH:10])=[CH:6][C:5]=1[OH:11].C(=O)([O-])[O-].[K+].[K+].[CH2:19](Br)[CH:20]=[CH2:21]>CC(C)=O>[CH3:1][O:2][C:3](=[O:12])[C:4]1[CH:9]=[CH:8][C:7]([O:10][CH2:21][CH:20]=[CH2:19])=[CH:6][C:5]=1[OH:11]

Participants

5

Reactant 3

HCID 7841Allyl bromideHCID 11430Potassium CarbonateHCID 16523Methyl 2,4-Dihydroxybenzoate

Product 1

HCID 13019278Methyl 2-hydroxy-4-[(prop-2-en-1-yl)oxy]benzoateYield 77%

Reagents, catalysts & solvents 1

HCID 180AcetoneSolvent

Procedure

To a solution of 2,4-dihydroxy-benzoic acid methyl ester (12.254 g, 72.8 mmol) in acetone (120 mL) was added potassium carbonate (30.72 g, 222.3 mmol) and allyl bromide (7 mL, 80.9 mmol). The reaction mixture was heated at reflux for 5 hours, and then cooled to room temperature. It was partitioned between ethyl acetate and brine and the aqueous layer was extracted with ethyl acetate. The combined organics were washed with brine, dried over anhydrous magnesium sulfate and concentrated in vacuo. The residue was purified by flash chromatography using ethyl acetate/hexanes (4/96) to afford 4-allyloxy-2-hydroxy-benzoic acid methyl ester (10.952 g, 77%) as a yellow oil. 1H NMR (300 MHz, CDCl3); δ 10.95 (s, 1H), 7.72 (d, 2H), 6.45 (m, 2H), 6.02 (m, 1H), 5.35 (m, 2H), 4.55 (d, 2H), 3.90 (s, 3H).

Workup

  1. temperatureThe reaction mixture was heated
  2. temperatureat reflux for 5 hours
  3. customIt was partitioned between ethyl acetate and brine
  4. extractionthe aqueous layer was extracted with ethyl acetate
  5. washThe combined organics were washed with brine
  6. dry with materialdried over anhydrous magnesium sulfate
  7. concentrationconcentrated in vacuo
  8. customThe residue was purified by flash chromatography

Sources & evidence

ORD record
ord-7fced78c4df249e9ac3f703c112a78d0
Source dataset
uspto-grants-2008_09
Patent number
US07420083B2

Linked notes

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