Dimethylformamide → HCID 13393784, compound

Participants

Reaction Steps

As in example 1, but using 2.4 g 5-hydroxy-flavanone, 20 ml dimethylformamide and 2.8 ml phosphorous oxychloride. Reaction time is forty hours at 75° C. After hydrolysis and usual work up the residual solid is purified by column chromatography. The best fractions are recrystallised in a mixture of toluene and hexane to give pure yellow crystalline 4-chloro-3-formyl-5-hydroxy-flav-3-ene; m.p. 165° C.

Provenance & Evidence