Hydrogen Bromide → 3-(4-Bromo-phenyl)-benzo[b]thiophen-6-ol

HRID 347156Notes

Reaction equation

HRID 347156 reaction equation
[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[C:9]3[CH:16]=[CH:15][C:14]([O:17]C)=[CH:13][C:10]=3[S:11][CH:12]=2)=[CH:4][CH:3]=1.Br>C(O)(=O)C>[Br:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]2[C:9]3[CH:16]=[CH:15][C:14]([OH:17])=[CH:13][C:10]=3[S:11][CH:12]=2)=[CH:4][CH:3]=1

Participants

4

Reactant 2

HCID 260Hydrogen BromideHCID 154226413-(4-Bromophenyl)-6-methoxybenzo[b]thiophene

Product 1

HCID 179328883-(4-Bromo-phenyl)-benzo[b]thiophen-6-olYield 98.4%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

7.4 g (23.17 mmol) 3-(4-Bromo-phenyl)-6-methoxy-benzo[b]thiophene in 47 ml acetic acid were treated with 27 ml (62% aq) HBr at 125° C. for 4 h. The solution was concentrated in vacuo and the residue was dissolved in NaHCO3 and EtOAc. Prior to extraction with EtOAc the pH was adjusted with 2M NaOH (pH 8). The combined organic phases were washed with brine and dried with Na2SO4. Trituration with hexane gave 6.96 g (98%) 3-(4-Bromo-phenyl)-benzo[b]thiophen-6-ol as light green solid, MS: 304 (M, 1Br).

Workup

  1. concentrationThe solution was concentrated in vacuo
  2. dissolutionthe residue was dissolved in NaHCO3
  3. extractionPrior to extraction with EtOAc the pH
  4. washThe combined organic phases were washed with brine
  5. dry with materialdried with Na2SO4

Sources & evidence

ORD record
ord-5047a2ceeb384b0aab01f5bbc791bf5c
Source dataset
uspto-grants-2007_02
Patent number
US07173043B2

Reaction notes

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