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

HRID 966291Notes

Reaction equation

HRID 966291 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-ee905a6a3f2c48619cda55e6f30e5078
Source dataset
uspto-grants-2005_10
Patent number
US06951879B2

Reaction notes

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