Reaktion #163545

Reaktionsgleichung

sodium carbonate

1-ethyl-1,4-dihydroquinoxaline-2,3-dione

POBr3

→

3-bromo-1-ethyl-quinoxalin-2(1H)-one

Ausbeute 53.0%

Lösungsmittel

dichloroethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturThe reaction mixture was refluxed
2. 2
   workup.ADDITIONtreated with ice cold
3. 3
   FiltrationThe mixture was filtered
4. 4
   Extraktionthe filtrate was extracted with dichloromethane
5. 5
   Trocknendried over anhydrous sodium sulfate
6. 6
   Einengenconcentrated

Vorschrift

To 2 g (10.5 mM) of 1-ethyl-1,4-dihydroquinoxaline-2,3-dione in 20 ml of dichloroethane were added dropwise 3.16 g (11.0 mM) of POBr3. The reaction mixture was refluxed under stirring for 2 h and then treated with ice cold and an aqueous sodium carbonate solution. The mixture was filtered and the filtrate was extracted with dichloromethane, dried over anhydrous sodium sulfate and concentrated to give 1.4 g of 3-bromo-1-ethyl-quinoxalin-2(1H)-one as a yellow solid. Yield: 53%.

Quelle