Hydrochloric Acid → Methyl 3-ethyl-1-benzofuran-2-carboxylate

HRID 29300Notes

Reaction equation

HRID 29300 reaction equation
[CH3:1][O:2][C:3](=[O:16])[CH2:4][O:5][C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=1[C:12](=O)[CH2:13][CH3:14].C[O-].[Na+].Cl>CO.O>[CH3:1][O:2][C:3]([C:4]1[O:5][C:6]2[CH:11]=[CH:10][CH:9]=[CH:8][C:7]=2[C:12]=1[CH2:13][CH3:14])=[O:16]

Participants

6

Reactant 3

HCID 313Hydrochloric AcidHCID 10942334Sodium MethoxideHCID 24701002(2-Propionyl-phenoxy)-acetic acid methyl ester

Product 1

HCID 66778182Methyl 3-ethyl-1-benzofuran-2-carboxylateYield 38%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 962WaterSolvent

Conditions

Temperature
60 °C

Procedure

(2-Propionyl-phenoxy)-acetic acid methyl ester (432 mg, 1.94 mmol, 1 eq.) was added to a solution of sodium methoxide (105 mg, 0.94 mmol, 1 eq.) in methanol (10 mL) and the reaction was heated at 60° C. for 4 h. The reaction was acidified using 1N HCl, diluted with water, extracted twice with ethyl acetate, and the combined organic layers were washed with saturated aqueous NaHCO3. The aqueous layers were extracted with ethyl acetate. The organic layers were combined, dried over magnesium sulfate, and concentrated in vacuo. 3-Ethyl-benzofuran-2-carboxylic acid methyl ester is obtained in 38% yield after flash column chromatography purification (1-5% ethyl acetate/hexanes). 1H NMR (400 MHz, DMSO-d6) δ ppm 1.2 (t, J=7.6 Hz, 3 H) 3.1 (q, J=7.6 Hz, 2 H) 3.9 (s, 3 H) 7.4 (m, 1 H) 7.5 (m, 1 H) 7.7 (m, 1 H) 7.9 (dd, J=7.8, 0.8 Hz, 1 H).

Workup

  1. extractionextracted twice with ethyl acetate
  2. washthe combined organic layers were washed with saturated aqueous NaHCO3
  3. extractionThe aqueous layers were extracted with ethyl acetate
  4. dry with materialdried over magnesium sulfate
  5. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-575928b05e424320a7fca9255b2bb20c
Source dataset
uspto-grants-2008_09
Patent number
US07420001B2

Reaction notes

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