Reaktion #6374

Reaktionsgleichung

2,4-dihydroxy-phenyl-benzyl-ketone

ethyl-orthoformate

morpholine

→

7-hydroxy-isoflavone

Ausbeute 90.6%

Lösungsmittel

chloroform

Reaktionsbedingungen

Aufarbeitung

1. 1
   SonstigeCrystallization
2. 2
   Temperaturafter heating for 25 minutes
3. 3
   SonstigeThe inert temperature falls back to 87° C. from 96° C. during the reaction
4. 4
   workup.STIRRINGAfter stirring for 5 hours the reaction mixture

Vorschrift

A mixture of 20 g (0.0877 mole) 2,4-dihydroxy-phenyl-benzyl-ketone, 20.7 g (0.14 mole) ethyl-orthoformate and 1 ml of morpholine is stirred on a hot water bath. Crystallization starts after heating for 25 minutes. The inert temperature falls back to 87° C. from 96° C. during the reaction. After stirring for 5 hours the reaction mixture is diluted with 48 ml of chloroform and then one may proceed as disclosed in Example 5. 18.9 g of 7-hydroxy-isoflavone are obtained.

Quelle