Hydrochloric Acid → Methyl 5-hydroxy-3-methylbenzo(b)thiophene-2-carboxylate

HRID 2248903Notes

Reaction equation

HRID 2248903 reaction equation
Cl.[OH:2][C:3]1[CH:15]=[CH:14][C:6]2[S:7][C:8]([C:11]([OH:13])=[O:12])=[C:9]([CH3:10])[C:5]=2[CH:4]=1.[CH3:16]O>>[OH:2][C:3]1[CH:15]=[CH:14][C:6]2[S:7][C:8]([C:11]([O:13][CH3:16])=[O:12])=[C:9]([CH3:10])[C:5]=2[CH:4]=1

Participants

4

Reactant 3

HCID 313Hydrochloric AcidHCID 887MethanolHCID 125755615-Hydroxy-3-methylbenzo[b]thiophene-2-carboxylic acid

Product 1

HCID 19994682Methyl 5-hydroxy-3-methylbenzo(b)thiophene-2-carboxylate

Procedure

Dry HCl gas is bubbled through a solution of 5-hydroxy-3-methylbenzo(b)thiophene-2-carboxylic acid (1.0 g, 4.81 mmol) in methanol (150 ml) for 1 hour at room temperature. The brown solution is refluxed for 2 hours and concentrated. Extraction with ether, washing with water, aqueous sodium bicarbonate, water and bring, drying (MgSO4) and concentration affords the crude product which is subjected to flash chromatography over silica gel. Elution with 33% ethyl acetate in hexane affords methyl 5-hydroxy-3-methylbenzo(b)thiophene-2-carboxylate.

Workup

  1. temperatureThe brown solution is refluxed for 2 hours
  2. concentrationconcentrated
  3. extractionExtraction with ether
  4. washwashing with water, aqueous sodium bicarbonate, water
  5. customdrying
  6. concentration(MgSO4) and concentration
  7. customaffords the crude product which
  8. washElution with 33% ethyl acetate in hexane

Sources & evidence

ORD record
ord-8930254b2c5743b782014f9bfa346773
Source dataset
uspto-grants-1991_08
Patent number
US05041453

Reaction notes

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