Treatment of 8-bromomethyl-2-phenylflavone (I) with KCN in EtOH-H2O for 3 h gives the nitrile intermediate (II) (m.p. 165-7 C) in 67% yield, which in diluted acetic-sulfuric acid is hydrolyzed to flavoneacetic acid (III) in 88% yield. On refluxing the potassium salt of the acid with 2-diethylaminoethyl chloride in acetone for 4 h, followed by converting the resulting ester to the hydrochloride salt, the diethylaminoethyl ester of flavoneacetic acid (m.p. 186 C) is produced in 70% yield.