Lithium Bromide → Benzo(b)thiophen-4-ol

HRID 1929235Notes

Reaction equation

HRID 1929235 reaction equation
Br[CH:2]1[CH2:10][CH2:9][C:5]2[S:6][CH:7]=[CH:8][C:4]=2[C:3]1=[O:11].[Li+].[Br-]>CN(C=O)C>[S:6]1[CH:7]=[CH:8][C:4]2[C:3]([OH:11])=[CH:2][CH:10]=[CH:9][C:5]1=2

Participants

4

Reactant 2

HCID 82050Lithium BromideHCID 129463875-Bromo-6,7-dihydro-1-benzothiophen-4(5H)-one

Product 1

HCID 19217Benzo(b)thiophen-4-ol

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

5-Bromo-6,7-dihydro-5H-benzo[b]thiophen-4-one (199, 77% pure, 8.7 g, 28.9 mmol), LiBr (5.7 g, 65.1 mmol) and Li2CO3 (4.3 g, 57.8 mmol) are placed under argon in 300 ml of DMF and refluxed for 3 h. The reaction mixture is allowed to cool down to room temperature and evaporated under high vacuum. After addition of ice water and cold 2M aqueous HCl solution the mixture is extracted with diethyl ether. The organic layers are extracted with 2M NaOH and the combined aqueous layers are acidified with concentrated HCl. The product is extracted twice with ethyl acetate and the organic layers are washed with saturated NaCl solution, dried over Na2SO4 and evaporated under reduced pressure.

Workup

  1. temperaturerefluxed for 3 h
  2. customevaporated under high vacuum
  3. additionAfter addition of ice water and cold 2M aqueous HCl solution the mixture
  4. extractionis extracted with diethyl ether
  5. extractionThe organic layers are extracted with 2M NaOH
  6. extractionThe product is extracted twice with ethyl acetate
  7. washthe organic layers are washed with saturated NaCl solution
  8. dry with materialdried over Na2SO4
  9. customevaporated under reduced pressure

Sources & evidence

ORD record
ord-e8179129dc7544579a2c133d837aefac
Source dataset
uspto-grants-2012_05
Patent number
US08183366B2

Reaction notes

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