Hydrochloric Acid → Methyl 2,3-dimethylbenzofuran-7-carboxylate

HRID 1761933Notes

Reaction equation

HRID 1761933 reaction equation
[CH3:1][O:2][C:3]([C:5]1[CH:17]=[CH:16][CH:15]=[C:14]([C:18](=O)[CH3:19])[C:6]=1[O:7][CH:8]([CH3:13])C(OC)=O)=[O:4].Cl.O1CCOCC1>O>[CH3:13][C:8]1[O:7][C:6]2[C:5]([C:3]([O:2][CH3:1])=[O:4])=[CH:17][CH:16]=[CH:15][C:14]=2[C:18]=1[CH3:19]

Participants

5

Reactant 3

HCID 313Hydrochloric AcidHCID 312751,4-DioxaneHCID 20043643Methyl 2-(2-methoxycarbonyl-6-acetylphenoxy)propionate

Product 1

HCID 14229732Methyl 2,3-dimethylbenzofuran-7-carboxylateYield 46%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 4.42 g of methyl 2-(2-methoxycarbonyl-6-acetylphenoxy)propionate, 20 ml of 6N hydrochloric acid and 20 ml of dioxane is refluxed for 10 minutes, and water is added to the reaction mixture. The aqueous mixture is extracted with ethyl acetate. The extract is washed with water, dried and evaporated to remove solvent. The residue is dissolved in 30 ml of tetrahydrofuran, and 5.55 ml of oxalyl chloride and a drop of dimethylformamide are added to the solution. The mixture is stirred for 1 hour. The reaction mixture is evaporated to remove solvent and the residue is dissolved in 100 ml of benzene. The solution is added dropwise to a refluxed solution of 6.66 ml of triethylamine in benzene and the mixture is refluxed for 5 hours. The reaction mixture is washed successively with 2% hydrochloric acid and water, dried and evaporated to remove solvent. The residue is purified by silica gel column chromatography (solvent; n-hexane:ethyl acetate=5:1) to give 1.48 g of methyl 2,3-dimethylbenzofuran-7-carboxylate.

Workup

  1. temperatureis refluxed for 10 minutes
  2. extractionThe aqueous mixture is extracted with ethyl acetate
  3. washThe extract is washed with water
  4. customdried
  5. customevaporated
  6. customto remove solvent
  7. dissolutionThe residue is dissolved in 30 ml of tetrahydrofuran
  8. addition5.55 ml of oxalyl chloride and a drop of dimethylformamide are added to the solution
  9. customThe reaction mixture is evaporated
  10. customto remove solvent
  11. dissolutionthe residue is dissolved in 100 ml of benzene
  12. additionThe solution is added dropwise to a refluxed solution of 6.66 ml of triethylamine in benzene
  13. temperaturethe mixture is refluxed for 5 hours
  14. washThe reaction mixture is washed successively with 2% hydrochloric acid and water
  15. customdried
  16. customevaporated
  17. customto remove solvent
  18. customThe residue is purified by silica gel column chromatography (solvent; n-hexane:ethyl acetate=5:1)

Sources & evidence

ORD record
ord-771ac11e5495476e898a017d633889a1
Source dataset
uspto-grants-1989_05
Patent number
US04829067

Reaction notes

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