Reaktion #4619

Reaktionsgleichung

chloroacetone

potassium carbonate

chloroacetone

2,3-dihydro-2,2-dimethyl-6-hydroxy-4H-1,3-benzoxazin-4-one

→

2,3-dihydro-2,2-dimethyl-6-(2-oxopropoxy)-4H-1,3-benzoxazin-4-one

Lösungsmittel

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturthe reaction mixture is heated for a further 15 to 20 hours
2. 2
   SonstigeThe still warm reaction mixture
3. 3
   Filtrationis filtered
4. 4
   Waschenthe residue thoroughly washed with acetone
5. 5
   Einengenthe combined filtrate is concentrated by evaporation
6. 6
   SonstigeThe crystalline residue is recrystallised from toluene

Vorschrift

70 g of 2,3-dihydro-2,2-dimethyl-6-hydroxy-4H-1,3-benzoxazin-4-one are refluxed for 30 hours, whilst stirring, in 400 ml of acetonitrile with 100 g of potassium carbonate and 32 ml of chloroacetone. After the addition of a further 3.2 ml of chloroacetone, the reaction mixture is heated for a further 15 to 20 hours. The still warm reaction mixture is filtered, the residue thoroughly washed with acetone and the combined filtrate is concentrated by evaporation. The crystalline residue is recrystallised from toluene and yields 2,3-dihydro-2,2-dimethyl-6-(2-oxopropoxy)-4H-1,3-benzoxazin-4-one having a melting point of 125°-126°.

Quelle