Disodium Malonate

Disodium malonate is a sodium salt of malonic acid with the chemical formula CH2(COONa)2. It is a white crystal soluble in water but not in alcohols, esters or benzene. It appears as a white crystalline powder, soluble in water. It can be prepared from the reaction of sodium hydroxide and malonic acid:

CH2(COOH)2 + 2 NaOH → CH2(COONa)2 + 2 H2O

It acts as a nucleophile in alkylation and condensation reactions due to the active methylene group between the two carbonyls. In biochemistry, malonate is a known competitive inhibitor of succinate dehydrogenase, an enzyme in the citric acid cycle. This inhibition disrupts cellular respiration.

Properties

Chemical formula: C3H2O4Na2
Molar mass: 148.025 g/mol
Boiling point: 659.93K
Appearance: White crystalline powder
Solubility in water: High
Melting point: Decomposes before melting
pH (aqueous solution): Slightly basic (~8-9)
Odor: Odorless
Hygroscopic: Slightly

Preparation

Disodium malonate is typically prepared by neutralizing malonic acid with sodium hydroxide (NaOH):

HOOC-CH2-COOH+2NaOH→NaOOC-CH2-COONa+2H2O

Occurrences

Natural Occurrence:

Does not occur naturally in significant amounts.
Malonic acid (its parent acid) is found in small amounts in certain fruits and plants but not commonly in its disodium salt form.

Industrial/Scientific Use:

Organic synthesis intermediate (used to synthesize barbiturates, vitamins like B1, and other complex molecules).
Buffer component in biochemical applications.
Precursor in the malonic ester synthesis.
Sometimes used in coordination chemistry to create metal-organic frameworks.

Applications

Used primarily in organic synthesis, it serves as a building block in the malonic ester synthesis to produce carboxylic acids. It is also used in research and teaching labs. It is relatively stable under normal conditions but should be handled with care in aqueous or acidic environments.

Safety and Handling