Dimethylformamide → 6-bromo-2,2-dimethyl-1-benzothiophen-3(2H)-one 1,1-dioxide

HRID 2390292Notes

Reaction equation

HRID 2390292 reaction equation
[Br:1][C:2]1[CH:13]=[CH:12][C:5]2[C:6](=O)[CH2:7][S:8](=[O:10])(=[O:9])[C:4]=2[CH:3]=1.[H-].[Na+].I[CH3:17].CN([CH:21]=[O:22])C>>[Br:1][C:2]1[CH:13]=[CH:12][C:5]2[C:21](=[O:22])[C:7]([CH3:6])([CH3:17])[S:8](=[O:9])(=[O:10])[C:4]=2[CH:3]=1

Participants

5

Reactant 4

HCID 6228DimethylformamideHCID 6328Methyl iodideHCID 24758Sodium hydrideHCID 565941086-Bromo-2,3-dihydro-1lambda6-benzothiophene-1,1,3-trione2×

Product 1

HCID 565941096-bromo-2,2-dimethyl-1-benzothiophen-3(2H)-one 1,1-dioxide

Procedure

A solution of 6-bromo-1-benzothiophen-3(2H)-one 1,1-dioxide (Intermediate 240; 1.00 g; 3.83 mmol) in anhydrous DMF (4 mL) was treated with sodium hydride (337 mg; 8.43 mmol) and stirred for 1 h. The resulting mixture was treated with iodomethane (715 μl; 11.5 mmol) and stirred for 15 min. The reaction was quenched with water, then partitioned between AcOEt and brine. The organic phase was washed with brine, dried on MgSO4, filtered and concentrated to give a residue which was purified by flash column chromatography (silica), eluting with cyclohexane containing increasing amounts of EtOAc. The title compound was obtained as an orange oil. Methyl 4-bromo-2-(isopropylsulfonyl)benzoate was also isolated and denominated as Intermediate 242.

Workup

  1. stirringstirred for 15 min
  2. customThe reaction was quenched with water
  3. custompartitioned between AcOEt and brine
  4. washThe organic phase was washed with brine
  5. customdried on MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customto give a residue which
  9. customwas purified by flash column chromatography (silica)
  10. washeluting with cyclohexane containing
  11. temperatureincreasing amounts of EtOAc

Sources & evidence

ORD record
ord-bed5b90431ad4a8b9f42c92ba39b8ddb
Source dataset
uspto-grants-2012_09
Patent number
US08273769B2

Reaction notes

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