Reaction #1106676

Reaction equation

Catechol

potassium carbonate

2-Chloromethyl-3-chloro-1-propene

→

3-methylene-3,4-dihydro-2H-benzo[b][1,4]dioxepine

Solvents

acetonitrile

Conditions

Workup

1. 1
   Temperatureheated
2. 2
   Temperatureto reflux for one hour
3. 3
   Temperatureat reflux for 24 hours
4. 4
   Filtrationfiltered
5. 5
   OtherThe filtrate was evaporated
6. 6
   workup.ADDITIONthe residue was diluted with water
7. 7
   Extractionextracted with diethyl ether (3×)
8. 8
   DryingThe combined organic solution was dried over MgSO4
9. 9
   Concentrationconcentrated

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.

Source