Reaktion #335034

Reaktionsgleichung

2-hydroxyacetophenon

acetone

pyrrolidine

→

3,4-dihydro-2,2-dimethyl-2H-benzo[b]pyran-4-one

Ausbeute 21.6%

Lösungsmittel

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturheated
2. 2
   Temperaturrefluxed
3. 3
   SonstigeTwenty hours
4. 4
   Sonstigewas returned to ambient temperature
5. 5
   workup.DISTILLATIONthe solvent was distilled off under reduced pressure, to which
6. 6
   workup.ADDITIONwas added 100 ml of 1N hydrogen chloride
7. 7
   ExtraktionThe extraction
8. 8
   Waschenby washing in water
9. 9
   Trocknendrying over anhydrous magnesium sulfate
10. 10
    Filtrationfiltering off
11. 11
    Sonstigecondensation of the filtered solution
12. 12
    SonstigeThe residue was purified on a silica gel column the fraction
13. 13
    workup.ADDITIONcontaining the purified product
14. 14
    workup.ADDITIONwere mixed together
15. 15
    workup.DISTILLATIONthe solvent therein was distilled off under reduced pressure

Vorschrift

Twenty five grams (25 g) of 2-hydroxyacetophenon, 10.7 g of acetone, and 5.5 g of pyrrolidine were added to 50 ml of toluene, and heated and refluxed. Twenty hours later, the temperature was returned to ambient temperature and the solvent was distilled off under reduced pressure, to which was added 100 ml of 1N hydrogen chloride. The extraction was carried out with 50 ml×3 of chloroform, followed by washing in water, drying over anhydrous magnesium sulfate, filtering off and condensation of the filtered solution. The residue was purified on a silica gel column the fraction containing the purified product were mixed together and the solvent therein was distilled off under reduced pressure to obtain 7 g of 3,4-dihydro-2,2-dimethyl-2H-benzo[b]pyran-4-one.

Quelle