Reaktion #82518

Reaktionsgleichung

diethyl ether

2,5-dichloroacetophenone

vinylmagnesium bromide

tetrahydrofuran

hydrochloric acid

→

3-hydroxy-3-(2,5-dichlorophenyl)-1-butene

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONUpon completion of addition the reaction mixture temperature
2. 2
   Temperaturis maintained at 10°-15° C. for two hours
3. 3
   Sonstigethe organic layer is separated
4. 4
   ExtraktionThe aqueous layer is extracted with two 50 mL portions of diethyl ether
5. 5
   WaschenThe combined organic layers are washed with one 50 mL portion of aqueous 5% hydrochloric acid solution
6. 6
   TrocknenThe organic layer is dried with magnesium sulfate
7. 7
   Filtrationfiltered
8. 8
   EinengenThe filtrate is concentrated under reduced pressure

Vorschrift

Under a nitrogen atmosphere, a stirred solution of 6.9 grams (0.053 mole) of vinylmagnesium bromide in 50 mL of tetrahydrofuran is cooled to 10°-15° C., and 10.0 grams (0.053 mole) of 2,5-dichloroacetophenone is added dropwise during a 20 minute period. Upon completion of addition the reaction mixture temperature is maintained at 10°-15° C. for two hours. After this time the reaction mixture is poured into 100 mL of cold aqueous 10% hydrochloric acid solution. The mixture is shaken with 100 mL of diethyl ether, and the organic layer is separated. The aqueous layer is extracted with two 50 mL portions of diethyl ether. The combined organic layers are washed with one 50 mL portion of aqueous 5% hydrochloric acid solution and then with two 30 mL portions of an aqueous solution saturated with sodium chloride. The organic layer is dried with magnesium sulfate and filtered. The filtrate is concentrated under reduced pressure, yielding 12.3 grams of 3-hydroxy-3-(2,5-dichlorophenyl)-1-butene. The NMR spectrum is consistent with the proposed structure.

Quelle