Reaktion #523448

Reaktionsgleichung

xanthene

4-chlorobutyryl chloride

aluminum chloride

→

2,7-bis(4-chlorobutyryl)xanthene

Lösungsmittel

methylene chloride

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturduring which the temperature is maintained below -10° C
2. 2
   workup.ADDITIONthe addition
3. 3
   Sonstigeto rise to room temperature
4. 4
   Temperaturrefluxed for an additional 4 hours
5. 5
   TemperaturUpon cooling
6. 6
   SonstigeThe liquid layers are separated
7. 7
   Extraktionthe aqueous layer extracted with methylene chloride
8. 8
   SonstigeThe combined organic layers are evaporated to a small volume
9. 9
   Temperaturcooled

Vorschrift

To a mixture of 91.1 g (0.5 mole) of xanthene, 176.3 g (1.25 moles) of 4-chlorobutyryl chloride and 3 liters of dry methylene chloride, chilled to -20° C., is slowly added over a 30 minute period 146.7 g (1.1 moles) of aluminum chloride, during which the temperature is maintained below -10° C. Following the addition, the reaction temperature is slowly permitted to rise to room temperature and then refluxed for an additional 4 hours. Upon cooling, the mixture is decomposed by cautiously pouring into 2 liters of an ice-water mixture. The liquid layers are separated and the aqueous layer extracted with methylene chloride. The combined organic layers are evaporated to a small volume and cooled. The resulting 2,7-bis(4-chlorobutyryl)xanthene so obtained is recrystallized from acetone to yield the desired product having a m.p. 131°-2° C.

Quelle