malonic acid ma·lo·nic acid (mə-lō'nĭk, -lŏn'ik)
n.
A white crystalline dicarboxylic acid derived from malic acid and used in the manufacture of barbiturates.
(HO2CCH2CO2H), a dibasic organic acid whose diethyl ester is used in syntheses of vitamins B1 and B6, barbiturates, and numerous other valuable compounds.