Dimethylformamide → HCID 13393786, compound

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Reaction Steps

As in example 1, but using 6 g 6-carboxy-flavanone, 60 ml dimethylformamide and 15 ml phosphorous oxychloride. Reaction time is three hours at 50° C. After hydrolysis a precipitate formed which is filtered, washed with water and dried over phosphorous pentoxyde. The residual solid is dissolved in a 10% sodium bicarbonate aqueous solution, which is then washed with methylene chloride. The aqueous phase is acidified with a 10% hydrochloric acid solution and the precipitate which formed is filtered, washed and dried. The residual solid is recrystallised in a mixture of hexane and ethyl acetate and pure 6-carboxy-4-chloro-3-formyl-flav-3-ene is obtained; m.p. 262°-267° C.

Provenance & Evidence