Reaktion #1269834

Reaktionsgleichung

1,1-Dicyano-2-hydroxy-2-(4-phenoxyphenyl)ethene

diisopropylethylamine

trimethylsilyldiazomethane

→

1,1-dicyano-2-methoxy-2-(4-phenoxyphenyl)ethene

Lösungsmittel

THF

acetonitrile

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITION2 g of silica is added (for chromatography)
2. 2
   SonstigeThe brown-red solution is evaporated in vacuo
3. 3
   workup.DISSOLUTIONthe residue dissolved in ethyl acetate
4. 4
   Waschenwashed well with water
5. 5
   Trocknenbrine, dried
6. 6
   Sonstigeevaporated
7. 7
   ExtraktionThe residue is extracted with diethyl ether (3×250 mL)
8. 8
   Sonstigedecanting from insoluble oil
9. 9
   SonstigeEvaporation of the ether

Vorschrift

1,1-Dicyano-2-hydroxy-2-(4-phenoxyphenyl)ethene (56.5 g) in acetonitrile (780 mL) and methanol (85 mL) is stirred under nitrogen at 0° C. while adding diisopropylethylamine (52.5 mL) followed by 2M trimethylsilyldiazomethane (150 mL) in THF. The reaction is stirred for 2 days at 20° C., and then 2 g of silica is added (for chromatography). The brown-red solution is evaporated in vacuo, the residue dissolved in ethyl acetate and washed well with water then brine, dried and evaporated. The residue is extracted with diethyl ether (3×250 mL), decanting from insoluble oil. Evaporation of the ether extracts gives 22.5 g of 1,1-dicyano-2-methoxy-2-(4-phenoxyphenyl)ethene as a pale orange solid. The insoluble oil is purified by flash chromatography to give 15.0 g of a red-orange oil.

Quelle