Allyl bromide → Methyl 4-allyloxy-2-hydroxy-5-isopropylbenzoate

HRID 1182802Notes

Reaction equation

HRID 1182802 reaction equation
[OH:1][C:2]1[CH:11]=[C:10]([OH:12])[C:9]([CH:13]([CH3:15])[CH3:14])=[CH:8][C:3]=1[C:4]([O:6][CH3:7])=[O:5].C(=O)([O-])[O-].[K+].[K+].[CH2:22](Br)[CH:23]=[CH2:24]>C(#N)C>[CH2:24]([O:12][C:10]1[C:9]([CH:13]([CH3:15])[CH3:14])=[CH:8][C:3]([C:4]([O:6][CH3:7])=[O:5])=[C:2]([OH:1])[CH:11]=1)[CH:23]=[CH2:22]

Participants

5

Reactant 3

HCID 7841Allyl bromideHCID 11430Potassium CarbonateHCID 59167875Methyl 2,4-dihydroxy-5-(propan-2-yl)benzoate

Product 1

HCID 58236466Methyl 4-allyloxy-2-hydroxy-5-isopropylbenzoateYield 65.9%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A mixture of methyl 2,4-dihydroxy-5-isopropylbenzoate (420 mg, 2.0 mmol) and anhydrous potassium carbonate (662 mg, 4.8 mmol) in acetonitrile (10 ml) was treated with allyl bromide (0.35 ml, 4.0 mmol) and the mixture was stirred at room temperature for 24 hours. The solvent was removed in vacuo and the residue acidified by the addition of 2M hydrochloric acid (10 ml). The organic material was extracted with dichloromethane (2×20 ml), the combined organic extracts were evaporated in vacuo and the residue subjected to column chromatography on silica. Elution with 2-10% ethyl acetate in petroleum ether afforded methyl 4-allyloxy-2-hydroxy-5-isopropylbenzoate (330 mg, 60%) as a colourless solid. 1H NMR (DMSO-d6) 10.68 (1H, s), 7.55 (1H, s), 6.54 (1H, s), 6.06 (1H, m), 5.42 (1H, dm), 5.29 (1H, dm), 4.65 (2H, m), 3.88 (3H, s), 3.16 (1H, m), 1.16 (6H, d).

Workup

  1. customThe solvent was removed in vacuo
  2. additionthe residue acidified by the addition of 2M hydrochloric acid (10 ml)
  3. extractionThe organic material was extracted with dichloromethane (2×20 ml)
  4. customthe combined organic extracts were evaporated in vacuo
  5. washElution with 2-10% ethyl acetate in petroleum ether

Sources & evidence

ORD record
ord-08796700aa334e4e96c032bde6606064
Source dataset
uspto-grants-2014_03
Patent number
US08664218B2

Reaction notes

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