Reaktion #74839

Reaktionsgleichung

3,4-difluorobenzoylacetonitrile

triethyl orthoacetate

acetic

→

title compound

2-(3,4-Difluorobenzoyl)-3-hydroxycrotononitrile

Lösungsmittel

water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONpoured into 200 ml
2. 2
   TemperaturOn cooling
3. 3
   Filtrationthe solid is filtered
4. 4
   workup.DISSOLUTIONdissolved in methylene chloride
5. 5
   ExtraktionThis solution is extracted with two portions of aqueous sodium bicarbonate
6. 6
   ExtraktionThe precipitate is extracted into methylene chloride
7. 7
   Temperaturheated
8. 8
   workup.ADDITIONdiluted with hexane
9. 9
   TemperaturUpon cooling
10. 10
    Sonstigecolorless crystals result

Vorschrift

A solution of 10.2 g. of 3,4-difluorobenzoylacetonitrile, 9.2 g. of triethyl orthoacetate and 20 ml. of acetic anhyride is heated on a steam bath for 0.5 hour and then poured into 200 ml. of water which is then heated on the steam bath for 2 hours. On cooling, the solid is filtered and then dissolved in methylene chloride. This solution is extracted with two portions of aqueous sodium bicarbonate and the aqueous extracts are combined and acidified with concentrated hydrochloric acid. The precipitate is extracted into methylene chloride, passed through a pad of Magnesol®, heated and diluted with hexane. Upon cooling, colorless crystals result, yielding the title compound, m.p. 51°-54° C.

Quelle