反応 #74839

反応方程式

3,4-difluorobenzoylacetonitrile

triethyl orthoacetate

acetic

→

title compound

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

溶媒

water

反応条件

後処理

1. 1
   workup.ADDITIONpoured into 200 ml
2. 2
   温度On cooling
3. 3
   ろ過the solid is filtered
4. 4
   workup.DISSOLUTIONdissolved in methylene chloride
5. 5
   抽出This solution is extracted with two portions of aqueous sodium bicarbonate
6. 6
   抽出The precipitate is extracted into methylene chloride
7. 7
   温度heated
8. 8
   workup.ADDITIONdiluted with hexane
9. 9
   温度Upon cooling
10. 10
    その他colorless crystals result

実験手順

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.

出典