Реакция #74839

Уравнение реакции

3,4-difluorobenzoylacetonitrile

triethyl orthoacetate

acetic

→

title compound

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

Растворители

water

Условия реакции

Обработка

1. 1
   workup.ADDITIONpoured into 200 ml
2. 2
   ТемператураOn cooling
3. 3
   Фильтрацияthe solid is filtered
4. 4
   workup.DISSOLUTIONdissolved in methylene chloride
5. 5
   ЭкстракцияThis solution is extracted with two portions of aqueous sodium bicarbonate
6. 6
   ЭкстракцияThe precipitate is extracted into methylene chloride
7. 7
   Температураheated
8. 8
   workup.ADDITIONdiluted with hexane
9. 9
   ТемператураUpon cooling
10. 10
    Другоеcolorless crystals result

Методика

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.

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