Water → 2-(4-Hydroxy-2-methyl-phenyl)-benzo[b]thiophene-5-carboxylic acid ethyl ester

HRID 2261818Notes

Reaction equation

HRID 2261818 reaction equation
B(Br)(Br)Br.[CH2:5]([O:7][C:8]([C:10]1[CH:27]=[CH:26][C:13]2[S:14][C:15]([C:17]3[CH:22]=[CH:21][C:20]([O:23]C)=[CH:19][C:18]=3[CH3:25])=[CH:16][C:12]=2[CH:11]=1)=[O:9])[CH3:6].O.C(Cl)(=O)C>ClCCl.C(OCC)(=O)C>[CH2:5]([O:7][C:8]([C:10]1[CH:27]=[CH:26][C:13]2[S:14][C:15]([C:17]3[CH:22]=[CH:21][C:20]([OH:23])=[CH:19][C:18]=3[CH3:25])=[CH:16][C:12]=2[CH:11]=1)=[O:9])[CH3:6]

Participants

7

Reactant 4

HCID 962WaterHCID 6367Acetyl chlorideHCID 25134Boron tribromideHCID 574433392-(4-Methoxy-2-methyl-phenyl)-benzo[b]thiophene-5-carboxylic acid ethyl ester

Product 1

HCID 672715912-(4-Hydroxy-2-methyl-phenyl)-benzo[b]thiophene-5-carboxylic acid ethyl esterYield 43.4%

Reagents, catalysts & solvents 2

HCID 6344DichloromethaneSolventHCID 8857Ethyl AcetateSolvent

Procedure

A 0° C. solution of boron tribromide (1M in dichloromethane, 1.29 mmol; 1.29 mL) is added under nitrogen atmosphere to a solution of 2-(4-methoxy-2-methyl-phenyl)-benzo[b]thiophene-5-carboxylic acid ethyl ester (1.07 mmol; 350 mg) in anhydrous dichloromethane (4.00 mL) and the mixture is stirred at room temperature for 4 h. Water and ethyl acetate are added. The aqueous layer is separated and the organic layer is dried (Na2SO4), filtered, and concentrated under reduced pressure. The residue is dissolved in ethanol (5 mL) and acetyl chloride (3.48 mmol, 0.25 mL) is added. The mixture is stirred at reflux for 5 h. The solvent is removed and the residue is chromatographed (5-20% EtOAc in hexanes) to yield the title compound (145 mg, 40%) as a white solid. LC-ES/MS m/e 313 (M+1).

Workup

  1. customThe aqueous layer is separated
  2. dry with materialthe organic layer is dried (Na2SO4)
  3. filtrationfiltered
  4. concentrationconcentrated under reduced pressure
  5. dissolutionThe residue is dissolved in ethanol (5 mL)
  6. stirringThe mixture is stirred
  7. temperatureat reflux for 5 h
  8. customThe solvent is removed
  9. customthe residue is chromatographed (5-20% EtOAc in hexanes)

Sources & evidence

ORD record
ord-d272594452704323af16f42de606ddd2
Source dataset
uspto-grants-2010_12
Patent number
US07846960B2

Reaction notes

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