Reaktion #4622

ord-d820998eb2b146de9eeca6c829a21010

Reaktionsbedingungen

Detaillierte Bedingungen
See reaction.notes.procedure_details.

Aufarbeitung

  1. 1
    Temperaturis refluxed for 4 hours
  2. 2
    SonstigeThe semi-liquid reaction mixture
  3. 3
    Extraktionis extracted 3 to 4 times whilst hot with 1 liter of methanol each time
  4. 4
    Einengenthe combined methanol extracts are concentrated by evaporation
  5. 5
    Sonstigethe residue is recrystallised from methanol

Vorschrift

A mixture of 48.2 g of 2,3-dihydro-2,2-dimethyl-6-hydroxy-4H-1,3-benzoxazin-4-one, 70 g of potassium carbonate and 250 ml of 1,2-dibromoethane is refluxed for 4 hours whilst stirring. The semi-liquid reaction mixture is extracted 3 to 4 times whilst hot with 1 liter of methanol each time; the combined methanol extracts are concentrated by evaporation and the residue is recrystallised from methanol. 6-(2-Bromoethoxy)-2,3-dihydro-2,2-dimethyl-4H-1,3-benzoxazin-4-one having a melting point of 190°-195° is obtained.

Quelle

DOI: 10.6084/m9.figshare.5104873.v1Patent: US04727067uspto-grants-1988_02