1,1-Dibromoethane → 5-Nitro-2,3-dihydro-1,4-benzodioxine

HRID 501524Notes

Reaction equation

HRID 501524 reaction equation
[N+:1]([C:4]1[CH:10]=[CH:9][CH:8]=[C:6]([OH:7])[C:5]=1[OH:11])([O-:3])=[O:2].[F-].[Cs+].Br[CH:15](Br)[CH3:16]>CN(C=O)C>[N+:1]([C:4]1[C:5]2[O:11][CH2:16][CH2:15][O:7][C:6]=2[CH:8]=[CH:9][CH:10]=1)([O-:3])=[O:2]

Participants

5

Reactant 3

HCID 112011,1-DibromoethaneHCID 25953Cesium fluorideHCID 4675622Nitrocatechol

Product 1

HCID 122313185-Nitro-2,3-dihydro-1,4-benzodioxineYield 20.8%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
110 °C

Procedure

To a solution of compound 8A (3.0 g, 19.4 mmol) in DMF (40 mL) was added CsF (14.7 g, 96.8 mmol), followed by dibromoethane (1.84 mL, 21.3 mmol). The mixture was heated to 110° C. for 1.5 h, then cooled to rt, partitioned between water and Et2O. The separated Et2O layer was washed with water, saturated aqueous NaHCO3, brine, dried (Na2SO4), filtered and concentrated under reduced pressure. The residue was chromatographed (silica gel) eluting with 5% MeOH in CH2Cl2 to afford the title compound (0.73 g).

Workup

  1. temperaturecooled to rt
  2. custompartitioned between water and Et2O
  3. washThe separated Et2O layer was washed with water, saturated aqueous NaHCO3, brine
  4. dry with materialdried (Na2SO4)
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customThe residue was chromatographed (silica gel)
  8. washeluting with 5% MeOH in CH2Cl2

Sources & evidence

ORD record
ord-44d647470b664f489f99e36568fd03f7
Source dataset
uspto-grants-2010_08
Patent number
US07772267B2

Reaction notes

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