Hydrogen Peroxide → 6-Benzyloxy-2,3-dibromo-benzo[b]thiophene 1-oxide

HRID 732819Notes

Reaction equation

HRID 732819 reaction equation
[CH2:1]([O:8][C:9]1[CH:10]=[CH:11][C:12]2[C:16]([Br:17])=[C:15]([Br:18])[S:14][C:13]=2[CH:19]=1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.FC(F)(F)C(O)=[O:23].OO.S(=O)(O)[O-].[Na+]>ClCCl.O>[CH2:1]([O:8][C:9]1[CH:10]=[CH:11][C:12]2[C:16]([Br:17])=[C:15]([Br:18])[S:14](=[O:23])[C:13]=2[CH:19]=1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1

Participants

7

Reactant 4

HCID 784Hydrogen PeroxideHCID 6422Trifluoroacetic acidHCID 23665763Sodium BisulfiteHCID 690752496-(Benzyloxy)-2,3-dibromo-1-benzothiophene

Product 1

HCID 690700516-Benzyloxy-2,3-dibromo-benzo[b]thiophene 1-oxideYield 62%

Reagents, catalysts & solvents 2

HCID 962WaterSolventHCID 6344DichloromethaneSolvent

Procedure

Dissolve 6-benzyloxy-2,3-dibromo-benzo[b]thiophene (20 g, 50 mmol) in dichloromethane (88 mL) and add trifluoroacetic acid (88 mL). Stir for 10 minutes, then add 30% aqueous solution of hydrogen peroxide (5.1 mL, 50 mmol) and stir for 4 hours. Add solid sodium bisulfite (2.2 g, 21 mmol), dilute with water (30 mL), stir for 15 minutes, and then concentrate in vacuo. Partition residue between dichloromethane (150 mL) and saturated aqueous sodium bicarbonate (150 mL), separate layers, wash organic layer with additional saturated aqueous sodium bicarbonate (150 mL) and brine (100 mL). Dry with sodium sulfate, filter, and concentrate in vacuo. Chromatograph on a SiO2 column eluting with 100% dichloromethane to give 12.8 g of 6-benzyloxy-2,3-dibromo-benzo[b]thiophene 1-oxide (62%).

Workup

  1. stirringstir for 4 hours
  2. stirringstir for 15 minutes
  3. concentrationconcentrate in vacuo
  4. customPartition residue between dichloromethane (150 mL) and saturated aqueous sodium bicarbonate (150 mL), separate layers
  5. washwash organic layer with additional saturated aqueous sodium bicarbonate (150 mL) and brine (100 mL)
  6. dry with materialDry with sodium sulfate
  7. filtrationfilter
  8. concentrationconcentrate in vacuo
  9. washChromatograph on a SiO2 column eluting with 100% dichloromethane

Sources & evidence

ORD record
ord-ba629b92115e4e83aa881f30d4b850d2
Source dataset
uspto-grants-2009_09
Patent number
US07585977B2

Reaction notes

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