反应详情

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.

1. additionpoured into 200 ml
2. temperatureOn cooling
3. filtrationthe solid is filtered
4. dissolutiondissolved in methylene chloride
5. extractionThis solution is extracted with two portions of aqueous sodium bicarbonate
6. extractionThe precipitate is extracted into methylene chloride
7. temperatureheated
8. additiondiluted with hexane
9. temperatureUpon cooling
10. customcolorless crystals result