말론산

개요Malonic acid (MA), also known as propanedioic acid, is a dicarboxylic acid with structure CH2(COOH)2. It have three kinds of crystal forms, of which two are triclinic, and one is monoclinic. That crystallized from ethanol is white triclinic crystals.It decomposes to acetic acid and carbon dioxide at 140℃. It does not decompose at 1.067×103~1.333×103Pa vacuum, but directly sublimates. The ionised form of malonic acid, as well as its esters and salts, are known as malonates. For example, diethyl malonate is malonic acid's ethyl ester. The name originates from Latin malum, meaning apple.

용도Malonic acid is used as an intermediate in the manufacture of barbiturates and other pharmaceuticals. It is a component used as a stabilizer in many high-end cosmetic and pharmaceutical products. Malonic acid is also used as building block in chemical synthesis, specifically to introduce the molecular group -CH2-COOH. It is used for the introduction of an acetic acid moiety under mild conditions by Knoevenagel condensation and subsequent decarboxylation.

일반 설명White crystals or crystalline powder. Sublimes in vacuum.

Malonic acid is usually produced from chloroacetic acid.Reaction: The chloroacetic acid is added to the reaction kettle by adding sodium carbonate aqueous solution to generate sodium chloroacetate aqueous solution, and then 30% sodium cyanide solution is slowly added dropwise, and the reaction is carried out at a predetermined temperature to generate sodium cyanoacetate. After the cyanation reaction is completed, add sodium hydroxide for heating and hydrolysis to generate sodium malonate solution, concentrate, then dropwise add sulfuric acid for acidification to generate malonic acid, filter and dry to obtain the product.This method often does not produce a pure enough product or the pure product has an extremely low yield. Industrially, malonic acid is also produced by hydrolyzing dimethyl malonate or diethyl malonate. This manufacturing method is able to bring about a higher yield and purity, but the organic synthesis of malonic acid through these processes is extremely costly and environmentally hazardous.