Catechol → 3-Methylene-3,4-dihydro-2H-1,5-benzodioxepin

HRID 660401Notes

Reaction equation

HRID 660401 reaction equation
[C:1]1([C:3](=[CH:5][CH:6]=[CH:7][CH:8]=1)[OH:4])[OH:2].C(=O)([O-])[O-].[K+].[K+].Cl[CH2:16][C:17]([CH2:19]Cl)=[CH2:18]>C(#N)C>[CH2:16]=[C:17]1[CH2:19][O:4][C:3]2[CH:5]=[CH:6][CH:7]=[CH:8][C:1]=2[O:2][CH2:18]1

Participants

5

Reactant 3

HCID 289CatecholHCID 11430Potassium CarbonateHCID 158593-Chloro-2-chloromethyl-1-propene

Product 1

HCID 5954503-Methylene-3,4-dihydro-2H-1,5-benzodioxepin

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

Catechol (5.09 g, 46.2 mmol) and potassium carbonate were combined in acetonitrile and heated to reflux for one hour. 2-Chloromethyl-3-chloro-1-propene (5.78 g, 46.2 mmol) was added and the reaction was continued at reflux for 24 hours. The solution was cooled to room temperature and filtered. The filtrate was evaporated and the residue was diluted with water and extracted with diethyl ether (3×). The combined organic solution was dried over MgSO4 and concentrated. Chromatography (2% ethyl ether in hexane) yielded 3-methylene-3,4-dihydro-2H-benzo[b][1,4]dioxepine as a colorless oil.

Workup

  1. temperatureheated
  2. temperatureto reflux for one hour
  3. temperatureat reflux for 24 hours
  4. filtrationfiltered
  5. customThe filtrate was evaporated
  6. additionthe residue was diluted with water
  7. extractionextracted with diethyl ether (3×)
  8. dry with materialThe combined organic solution was dried over MgSO4
  9. concentrationconcentrated

Sources & evidence

ORD record
ord-52cbea49617b44faa83030e2bc163169
Source dataset
uspto-grants-2011_12
Patent number
US08084490B2

Reaction notes

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