Water → 6-bromo-3,4-dihydro-9-methoxy-2H-1,5-benzodioxepin

HRID 2084827Notes

Reaction equation

HRID 2084827 reaction equation
[Br:1][C:2]1[CH:8]=[CH:7][C:6]([O:9][CH3:10])=[C:4]([OH:5])[C:3]=1[OH:11].Br[CH2:13][CH2:14][CH2:15]Br.[F-].[K+].O>CN(C=O)C>[Br:1][C:2]1[C:3]2[O:11][CH2:15][CH2:14][CH2:13][O:5][C:4]=2[C:6]([O:9][CH3:10])=[CH:7][CH:8]=1

Participants

6

Reactant 4

HCID 962WaterHCID 80011,3-DibromopropaneHCID 522689Potassium FluorideHCID 37058743-Bromo-6-methoxybenzene-1,2-diol

Product 1

HCID 232723376-bromo-3,4-dihydro-9-methoxy-2H-1,5-benzodioxepin

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
110 °C

Procedure

3-bromo-6-methoxycatechol (31 g) was dissolved in DMF (50 ml), mixed with 1,3-dibromopropane (36 ml) and potassium fluoride (42 g), stirred for 12 hours while heating at 110° C. The resultant was allowed to stand for cooling, mixed with water, and extracted with ether. The organic layer was washed with an aqueous sodium hydroxide solution, water, and a saturated aqueous sodium chloride solution in that order, dried over manganese sulfate, and evaporated under reduced pressure for removing the solvent. The residue was purified by silica gel column chromatography (hexane/ethyl acetate=7/1) to give Compound IIbr-a (6.7 g, 18%) as a white solid.

Workup

  1. temperaturefor cooling
  2. extractionextracted with ether
  3. washThe organic layer was washed with an aqueous sodium hydroxide solution, water
  4. dry with materiala saturated aqueous sodium chloride solution in that order, dried over manganese sulfate
  5. customevaporated under reduced pressure
  6. customfor removing the solvent
  7. customThe residue was purified by silica gel column chromatography (hexane/ethyl acetate=7/1)
  8. customto give Compound IIbr-a (6.7 g, 18%) as a white solid

Sources & evidence

ORD record
ord-b085775180fb4db182c339eea535ffe8
Source dataset
uspto-grants-2004_04
Patent number
US06716987B1

Reaction notes

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