Methyl 4-Allyl-3-hydroxy-5-methoxybenzoate → 2,3-Dihydro-4-methoxy-2-methyl-6-benzofurancarboxylic acid

HRID 613999Notes

Reaction equation

HRID 613999 reaction equation
C[O:2][C:3](=[O:16])[C:4]1[CH:9]=[C:8]([O:10][CH3:11])[C:7]([CH2:12][CH:13]=[CH2:14])=[C:6]([OH:15])[CH:5]=1>C(O)(=O)C>[CH3:11][O:10][C:8]1[C:7]2[CH2:12][CH:13]([CH3:14])[O:15][C:6]=2[CH:5]=[C:4]([C:3]([OH:2])=[O:16])[CH:9]=1

Participants

3

Reactant 1

HCID 53889137Methyl 4-Allyl-3-hydroxy-5-methoxybenzoate

Product 1

HCID 213298312,3-Dihydro-4-methoxy-2-methyl-6-benzofurancarboxylic acidYield 60%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

1 gram of 4-allyl-3-hydroxy-5-methoxybenzoic acid methyl ester in 5 cc of glacial acetic acid and 1.5 cc of 48%HBR is refluxed for 3 hours. After this time the mixture is concentrated to dryness and the crude residue is dissolved in an aqueous alkali solution. 0.3 grams of dimethyl sulfate are added to the resulting solution which is refluxed for two additional hours. The compound of the title which precipitates upon acidification of the cooled reaction mixture is recrystallized from ethyl ether-petroleum ether. Yield 60%. M.p. 180°-182° C.

Workup

  1. concentrationAfter this time the mixture is concentrated to dryness
  2. dissolutionthe crude residue is dissolved in an aqueous alkali solution
  3. addition0.3 grams of dimethyl sulfate are added to the resulting solution which
  4. temperatureis refluxed for two additional hours
  5. customThe compound of the title which precipitates upon acidification of the cooled reaction mixture
  6. customis recrystallized from ethyl ether-petroleum ether

Sources & evidence

ORD record
ord-8df4405deeaf4a7b931346688ed3dcde
Source dataset
uspto-grants-1979_03
Patent number
US04143055

Reaction notes

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