تفاعل #74839

معادلة التفاعل

3,4-difluorobenzoylacetonitrile

triethyl orthoacetate

acetic

→

title compound

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

المذيبات

water

ظروف التفاعل

المعالجة

1. 1
   workup.ADDITIONpoured into 200 ml
2. 2
   درجة الحرارةOn cooling
3. 3
   ترشيحthe solid is filtered
4. 4
   workup.DISSOLUTIONdissolved in methylene chloride
5. 5
   استخلاصThis solution is extracted with two portions of aqueous sodium bicarbonate
6. 6
   استخلاصThe precipitate is extracted into methylene chloride
7. 7
   درجة الحرارةheated
8. 8
   workup.ADDITIONdiluted with hexane
9. 9
   درجة الحرارةUpon cooling
10. 10
    أخرىcolorless crystals result

الإجراء التجريبي

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.

المصدر