Water → 8-Bromo-2,3-dihydro-1,4-benzodioxine-6-carbaldehyde

HRID 1677296Notes

Reaction equation

HRID 1677296 reaction equation
[Br:1][C:2]1[CH:3]=[C:4]([CH:7]=[C:8]([OH:11])[C:9]=1[OH:10])[CH:5]=[O:6].C([O-])([O-])=O.[K+].[K+].Br[CH2:19][CH2:20]Br.O>CN(C=O)C>[Br:1][C:2]1[C:9]2[O:10][CH2:19][CH2:20][O:11][C:8]=2[CH:7]=[C:4]([CH:5]=[O:6])[CH:3]=1

Participants

6

Reactant 4

HCID 962WaterHCID 78391,2-Dibromoethane2×HCID 11430Potassium CarbonateHCID 854055-Bromo-3,4-dihydroxybenzaldehyde

Product 1

HCID 166371768-Bromo-2,3-dihydro-1,4-benzodioxine-6-carbaldehydeYield 501.6%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Conditions

Temperature
100 °C

Procedure

To a solution of 3-bromo-4,5-dihydroxy-benzaldehyde (20.78 g, 95 mmol) in 480 ml DMF was added K2CO3 (52.95 g, 383 mmol) followed by 1,2-dibromoethane (8.7 ml, 101 mmol). The mixture was warmed to 100° C. After 18 additional 1,2 dibromoethane (1.0 mL) was added. After 2 h the mixture was poured into water and extracted with ethyl acetate. The combined organics were washed with brine, dried over Na2SO4, filtered and concentrated in vacuo. The crude solid was purified via flash chromatography (9:1 hexane/ethyl acetate) to give 8-bromo-2,3-dihydro-benzo[1,4]dioxine-6-carboxaldehyde (115.82 g, 99%) as a white solid.

Workup

  1. extractionextracted with ethyl acetate
  2. washThe combined organics were washed with brine
  3. dry with materialdried over Na2SO4
  4. filtrationfiltered
  5. concentrationconcentrated in vacuo
  6. customThe crude solid was purified via flash chromatography (9:1 hexane/ethyl acetate)

Sources & evidence

ORD record
ord-df424fe315204a04bcc9370560c5e194
Source dataset
uspto-grants-2011_08
Patent number
US08008313B2

Reaction notes

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