Reacción #74839

Ecuación de reacción

3,4-difluorobenzoylacetonitrile

triethyl orthoacetate

acetic

→

title compound

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

Disolventes

water

Condiciones de reacción

Tratamiento posterior

1. 1
   workup.ADDITIONpoured into 200 ml
2. 2
   TemperaturaOn cooling
3. 3
   Filtraciónthe solid is filtered
4. 4
   workup.DISSOLUTIONdissolved in methylene chloride
5. 5
   ExtracciónThis solution is extracted with two portions of aqueous sodium bicarbonate
6. 6
   ExtracciónThe precipitate is extracted into methylene chloride
7. 7
   Temperaturaheated
8. 8
   workup.ADDITIONdiluted with hexane
9. 9
   TemperaturaUpon cooling
10. 10
    Otrocolorless crystals result

Procedimiento

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.

Fuente