2'-Hydroxyacetophenone → 3-Formylchromone

Participants

Reaction Steps

In 80 volume parts of diemthylformamide there is dissolved 25 parts of orthohydroxyacetophenone and while the solution is externally cooled to about -20°C with dry ice-acetone, 80 volume parts of tetrachloropyrophosphate is added in small installments. The mixture is stirred at room temperature for 13 hours. The reaction mixture is then poured into ice-water and the resulting crystals are recovered by filtration, washed with water and ethanol and finally recrystallized from acetone. There is obtained a 19.6 parts yield of 4-oxo-4H-1-benzopyran-3-carboxaldehyde, as colorless crystals, melting at 152°-153°C.

Provenance & Evidence