Reaktion #354142

Reaktionsgleichung

4-hydroxy-3-methylacetophenone

K2CO3

1,3-dibromopropane

→

1-[4-(3-bromopropoxy)-3-methylphenyl]ethanone

Lösungsmittel

acetonitrile

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturwas heated
2. 2
   Temperaturat reflux for 6 hours
3. 3
   SonstigeAt the end of the reaction
4. 4
   Sonstigethe solvent was removed on a rotary evaporator
5. 5
   Extraktionthe crude solid was extracted into dichloromethane (750 ml)
6. 6
   FiltrationThe insoluble inorganics were filtered off
7. 7
   EinengenThe dichloromethane solution was concentrated again to a crude oil (34.5 g)
8. 8
   SonstigePurification
9. 9
   Waschenwas effected by flash chromatography over a silica gel column (SiO2, 150 g; eluted with 7:3 hexane:dichloromethane, 2 l; and dichloromethane 2 l)
10. 10
    SonstigeThe material thus purified
11. 11
    Sonstigewas recrystallized from ethanol
12. 12
    SonstigeRecrystallization again from ethanol

Vorschrift

A mixture of 4-hydroxy-3-methylacetophenone (14.5 g, 96 mmol), K2CO3 (17.5 g, 144 mmol), and 1,3-dibromopropane (30 g, 144 mmol) in acetonitrile (400 ml) was heated at reflux for 6 hours. At the end of the reaction, the solvent was removed on a rotary evaporator, and the crude solid was extracted into dichloromethane (750 ml). The insoluble inorganics were filtered off. The dichloromethane solution was concentrated again to a crude oil (34.5 g). Purification was effected by flash chromatography over a silica gel column (SiO2, 150 g; eluted with 7:3 hexane:dichloromethane, 2 l; and dichloromethane 2 l). The material thus purified weighed 14.6 g (56%) and was recrystallized from ethanol. Recrystallization again from ethanol gave analytically pure 1-[4-(3-bromopropoxy)-3-methylphenyl]ethanone, m.p.=59°-61° C.

Quelle