(2-Bromophenyl)(2,2-diethoxyethyl)sulfane → 7-Bromobenzo[b]thiophene

HRID 275810Notes

Reaction equation

HRID 275810 reaction equation
C(O[CH:4](OCC)[CH2:5][S:6][C:7]1[CH:12]=[CH:11][CH:10]=[CH:9][C:8]=1[Br:13])C>ClC1C=CC=CC=1>[Br:13][C:8]1[C:7]2[S:6][CH:5]=[CH:4][C:12]=2[CH:11]=[CH:10][CH:9]=1

Participants

3

Reactant 1

HCID 12045537(2-Bromophenyl)(2,2-diethoxyethyl)sulfane

Product 1

HCID 120455387-Bromobenzo[b]thiopheneYield 93.2%

Reagents, catalysts & solvents 1

HCID 7964ChlorobenzeneSolvent2×

Procedure

Chlorobenzene (100 mL) and polyphosphoric acid (30.4 g, PPA) were combined and heated to reflux. The 2-(2-bromophenylthio) acetaldehyde diethyl acetal (13.7 g, 44.88 mmol, Scheme I, step A above) dissolved in chlorobenzene (20 mL) was added dropwise to the refluxing mixture over 20 minutes. The reaction was refluxed for 4 hours and then cooled. The solvent was decanted from the residue and toluene (2×50 mL) was added to the residue, stirred and decanted. The chlorobenzene/toluene extracts were concentrated under vacuum and the residue taken up in ethyl acetate and water. The organic phase was washed with saturated sodium bicarbonate, dried over anhydrous sodium sulfate, filtered and concentrated to provide 7-bromobenzo(b)thiophene (8.91 g, 93%).

Workup

  1. temperatureheated to reflux
  2. additionwas added dropwise to the refluxing mixture over 20 minutes
  3. temperatureThe reaction was refluxed for 4 hours
  4. temperaturecooled
  5. customThe solvent was decanted from the residue and toluene (2×50 mL)
  6. additionwas added to the residue
  7. customdecanted
  8. concentrationThe chlorobenzene/toluene extracts were concentrated under vacuum
  9. washThe organic phase was washed with saturated sodium bicarbonate
  10. dry with materialdried over anhydrous sodium sulfate
  11. filtrationfiltered
  12. concentrationconcentrated

Sources & evidence

ORD record
ord-db17cf2d993a4ca3a6d1adfba9274a05
Source dataset
uspto-grants-2002_03
Patent number
US06353008B1

Reaction notes

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