Reaktion #78379

Reaktionsgleichung

water

methyl isobutyrylacetate

4-fluorobenzonitrile

tin tetrachloride

→

methyl 2-[1-amino-1-(4-fluorophenyl)methylene]-4-methyl-3-oxopentanoate

Ausbeute 81.5%

Lösungsmittel

toluene

ethyl acetate

n-hexane

toluene

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.WAITAfter half an hour at room temperature
2. 2
   Temperaturthe suspension was cooled to room temperature
3. 3
   Sonstigethe phases were separated
4. 4
   ExtraktionAfter extraction of the aqueous phase with ethyl acetate (2×100 ml)
5. 5
   Waschenthe combined organic phases were washed with 100 ml of saturated aqueous sodium hydrogencarbonate solution, and 100 ml of 1N sodium hydroxide solution
6. 6
   Trocknendried over magnesium sulphate
7. 7
   EinengenAfter concentration in vacuo
8. 8
   Sonstige46.46 g of crude product were obtained in the form of a yellowish solid
9. 9
   Temperaturunder reflux
10. 10
    Filtrationfiltered hot
11. 11
    SonstigeThe product precipitated from the filtrate
12. 12
    Temperaturon cooling
13. 13
    FiltrationBy filtering through a frit
14. 14
    Waschenwashing the filter cake with 2×40 ml of n-hexane

Vorschrift

22.53 g of methyl isobutyrylacetate (0.15 mol, concentration 96%) and 18.54 g of 4-fluorobenzonitrile (0.15 mol, concentration 98%) were dissolved in 150 ml of toluene and treated with 43.32 g of tin tetrachloride (0.165 mol, concentration 99%) at room temperature over the course of 12 min. After half an hour at room temperature, the mixture was heated to 80° C. After 3 h, the suspension was cooled to room temperature and treated with 150 ml of water. It was diluted with 100 ml of ethyl acetate and the phases were separated. After extraction of the aqueous phase with ethyl acetate (2×100 ml), the combined organic phases were washed with 100 ml of saturated aqueous sodium hydrogencarbonate solution, and 100 ml of 1N sodium hydroxide solution and dried over magnesium sulphate. After concentration in vacuo, 46.46 g of crude product were obtained in the form of a yellowish solid. The solid was dissolved in a mixture of 50 ml of n-hexane and 5 ml of toluene under reflux and filtered hot. The product precipitated from the filtrate on cooling. By filtering through a frit and washing the filter cake with 2×40 ml of n-hexane, 32.42 g of methyl 2-[1-amino-1-(4-fluorophenyl)methylene]-4-methyl-3-oxopentanoate were obtained in the form of a spectroscopically pure solid.

Quelle