Reaktion #1596943

Reaktionsgleichung

hydrochloric acid

1-benzyloxy-4-bromo-2-fluorobenzene

N-formylmorpholine

magnesium

→

4-benzyloxy-3-fluorobenzaldehyde

Lösungsmittel

MTBE

THF

THF

THF

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperatura gentle reflux
2. 2
   Temperaturis maintained
3. 3
   Sonstigeafter initiation of the Grignard reaction
4. 4
   workup.ADDITIONWhen the addition
5. 5
   Temperaturthe batch is heated at the boil for 1 h
6. 6
   SonstigeThe organic phase is separated off
7. 7
   Extraktionthe aqueous phase is extracted with MTBE
8. 8
   WaschenThe combined organic phases are washed with saturated sodium chloride solution
9. 9
   Sonstigedried
10. 10
    EinengenThe solution is concentrated to dryness
11. 11
    Sonstigethe crude product is recrystallised from n-heptane

Vorschrift

25.9 g (1.07 mol) of magnesium turnings are initially introduced in 200 ml of THF, and a solution of 285.6 g (1.02 mol) of 1-benzyloxy-4-bromo-2-fluorobenzene in 700 ml of THF is added dropwise at such a rate that a gentle reflux is maintained after initiation of the Grignard reaction. When the addition is complete, the mixture is diluted with 1000 ml of THF, and the batch is heated at the boil for 1 h. The solution of the Grignard reagent is cooled to 0° C., and 118 ml (1.07 mol) of N-formylmorpholine in 100 ml of THF are added dropwise. After 1 h, the mixture is diluted with MTBE and hydrolysed using dilute hydrochloric acid. The organic phase is separated off, and the aqueous phase is extracted with MTBE. The combined organic phases are washed with saturated sodium chloride solution and dried using sodium sulfate. The solution is concentrated to dryness, and the crude product is recrystallised from n-heptane:MTBE.

Quelle