Oxalyl chloride → HCID 12701107, compound

HRID 521390Notes

Reaction equation

HRID 521390 reaction equation
[C:1](Cl)(=[O:5])[C:2](Cl)=[O:3].[Br:7][C:8]1[CH:9]=[C:10]([SH:14])[CH:11]=[CH:12][CH:13]=1.[Cl-].[Al+3].[Cl-].[Cl-]>CCOCC.CCOC(C)=O>[Br:7][C:8]1[CH:13]=[CH:12][C:11]2[C:2](=[O:3])[C:1](=[O:5])[S:14][C:10]=2[CH:9]=1

Participants

6

Reactant 3

HCID 65578Oxalyl chlorideHCID 80597m-BromobenzenethiolHCID 6451240Aluminum(III) Chloride

Product 1

HCID 12701107HCID 12701107, compoundYield 50.2%

Reagents, catalysts & solvents 2

HCID 3283Diethyl EtherSolventHCID 8857Ethyl AcetateSolvent

Procedure

Oxalyl chloride (3.7 mL, 42 mmol) was added dropwise to a solution of 3-bromothiophenol (5.00 g, 26.4 mmol) in ether (20 mL). The mixture was heated at reflux for 1.5 hours, cooled to room temperature, and concentrated in vacuo. The resulting residue was taken up in DCM (50 mL) and cooled to 0° C. Aluminum chloride (4.23 g, 31.7 mmol) was added in portions. The resultant mixture was stirred at reflux for 30 minutes, cooled to room temperature and poured into ice water with stirring. The organic layer was separated and successively washed with saturated aqueous NaHCO3, water and brine. The organic layer was dried and concentrated in vacuo to give a solid, which was suspended in 20% EtOAc in hexanes (50 mL) and heated at reflux for 10 minutes. After cooling, the precipitated solid was collected by filtration to afford crude 6-bromobenzo[b]thiophene-2,3-dione (3.22 g, 50%). The 6-bromobenzo[b]thiophene-2,3-dione was added to ammonium hydroxide (35% aqueous solution, 40 mL) at 5-10° C., followed by dropwise addition of hydrogen peroxide (35% aqueous solution, 5.5 mL, 66 mmol). The resulting mixture was stirred at room temperature for 30 minutes, and then filtered to give 6-bromobenzo[b]thiophene-3-carboxamide (1.30 g, 38%) as a solid. 1H NMR (DMSO-d6, 400 MHz) δ □8.66 (d, J=8.8 Hz, 1H), 8.62 (s, 1H), 8.23 (s, 1H), 7.81 (s, 1H), 7.73 (d, J=8.8 Hz, 1H).

Workup

  1. temperatureThe mixture was heated
  2. temperatureat reflux for 1.5 hours
  3. concentrationconcentrated in vacuo
  4. temperaturecooled to 0° C
  5. temperatureat reflux for 30 minutes
  6. temperaturecooled to room temperature
  7. customThe organic layer was separated
  8. washsuccessively washed with saturated aqueous NaHCO3, water and brine
  9. customThe organic layer was dried
  10. concentrationconcentrated in vacuo
  11. customto give a solid, which
  12. temperatureheated
  13. temperatureat reflux for 10 minutes
  14. temperatureAfter cooling
  15. filtrationthe precipitated solid was collected by filtration

Sources & evidence

ORD record
ord-2b9fcbf523454c3fa84edb9c0fc3ad08
Source dataset
uspto-grants-2016_05
Patent number
US09328091B2

Reaction notes

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