반응 #54936

반응 방정식

orthohydroxyacetophenone

dry ice acetone

→

4-oxo-4H-1-benzopyran-3-carboxaldehyde

용매

dimethylformamide

반응 조건

후처리

1. 1
   workup.ADDITIONare added dropwise to the solution
2. 2
   여과the resulting crystals are recovered by filtration
3. 3
   세척washed with water and ethanol
4. 4
   기타finally recrystallized from acetone

실험 절차

In 80 volume parts of dimethylformamide are dissolved 25 parts of orthohydroxyacetophenone and, while the solution is externally cooled to about -20° C. with dry ice-acetone, 80 volume parts of tetrachloropyrophosphoric acid are added dropwise to the solution. The resulting mixture is stirred at room temperature for 13 hours. Then, the reaction mixture is poured into ice water and the resulting crystals are recovered by filtration, washed with water and ethanol and finally recrystallized from acetone. The procedure yields of 4-oxo-4H-1-benzopyran-3-carboxaldehyde as colorless crystals melting at 152°-153° C.

출처