Sulfuric Acid → methyl 2,3-dihydrobenzofuran-5-carboxylate

HRID 2181645Notes

Reaction equation

HRID 2181645 reaction equation
[O:1]1[C:5]2[CH:6]=[CH:7][C:8]([C:10]([OH:12])=[O:11])=[CH:9][C:4]=2[CH2:3][CH2:2]1.S(=O)(=O)(O)O.[C:18](=O)(O)[O-].[Na+]>CO>[O:1]1[C:5]2[CH:6]=[CH:7][C:8]([C:10]([O:12][CH3:18])=[O:11])=[CH:9][C:4]=2[CH2:3][CH2:2]1

Participants

5

Reactant 3

HCID 1118Sulfuric AcidHCID 516892Sodium BicarbonateHCID 6765832,3-Dihydrobenzo(b)furan-5-carboxylic acid

Product 1

HCID 2821720methyl 2,3-dihydrobenzofuran-5-carboxylateYield 98%

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent

Procedure

To a stirred solution of 2,3-dihydrobenzofuran-5-carboxylic acid (3.96 g, 24.1 mmol) in MeOH (200 mL) is added concentrated sulfuric acid (0.5 mL). The mixture is heated to reflux for 24 h. The mixture is cooled to rt, followed by the addition of solid sodium bicarbonate. The reaction mixture is concentrated in vacuo, and the remaining residue is partitioned between EtOAc and water. The aqueous layer is extracted with EtOAc, and the combined organic layers are dried (MgSO4), filtered and concentrated in vacuo to afford 4.22 g (98%) of methyl 2,3-dihydrobenzofuran-5-carboxylate as a white solid. 1H NMR (400 MHz, CDCl3) δ 7.93-7.89, 6.82, 4.69, 3.86, 3.28.

Workup

  1. temperatureThe mixture is heated
  2. temperatureto reflux for 24 h
  3. concentrationThe reaction mixture is concentrated in vacuo
  4. customthe remaining residue is partitioned between EtOAc and water
  5. extractionThe aqueous layer is extracted with EtOAc
  6. dry with materialthe combined organic layers are dried (MgSO4)
  7. filtrationfiltered
  8. concentrationconcentrated in vacuo

Sources & evidence

ORD record
ord-64f4b7366b3a4f8abbb92aa72e26373d
Source dataset
uspto-grants-2005_05
Patent number
US06894042B2

Reaction notes

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