What Is Malonic Acid?
Malonic acid is a dicarboxylic acid characterized by two carboxylic groups (-COOH). In its salt form, it is known as malonate. Derived from the Greek word for apple, the CAS registration number for malonic acid is 141-82-2.
For safe storage, malonic acid should be kept in a cool, well-ventilated place away from direct sunlight. Glass is recommended as a safe container and packaging material.
Uses of Malonic Acid
Malonic acid, found in apples, is used as a flavoring agent in the medical field and others. Its carboxyl group also makes it valuable in the synthesis of resins and adhesives.
Properties of Malonic Acid
Malonic acid appears as a white or almost white crystalline powder. It has a melting point of 275°F (135°C) and is solid at room temperature and pressure. Upon heating to slightly above its melting point, it decomposes into acetic acid and carbon dioxide. Malonic acid is soluble in water, ethanol, and acetone.
Structure of Malonic Acid
With the chemical formula HOOCCH2COOH, malonic acid has a molecular weight of 104.06. It is part of the acetic acid-malonic acid metabolic pathway.
Malonic acid’s diester is an active methylene compound. The methylene proton can be readily abstracted by a base to form a carbanion, which is useful in forming carbon-carbon bonds.
Other Information on Malonic Acid
1. Malonic Acid in Biochemistry
Malonic acid’s structure closely resembles succinic acid (HOOC-(CH2)2-COOH). It can bind to the active site of succinate dehydrogenase in the citric acid cycle, inhibiting the metabolism of succinate and thereby interfering with cellular respiration.
2. Malonic Acid in Pathology
Elevated levels of malonic acid, along with methylmalonic acid, may indicate a metabolic disorder known as combined malonic and methylmalonic aciduria. This condition can be distinguished from classical methylmalonic aciduria by analyzing the ratio of malonic acid to methylmalonic acid in plasma.
3. Advantages of Malonic Acid Ester Synthesis
Malonic ester synthesis is a method for obtaining α-substituted acetic esters using carbanions generated from malonic acid esters. This synthesis provides a synthetic advantage in forming C-C bonds without the need for strong acids or bases.
4. Mechanism of Malonic Acid Ester Synthesis
In this synthesis, a base is added to a malonic acid ester to generate a carbanion, which is stabilized by resonance with two carbonyl groups. Reacting this carbanion with an alkyl halide (R-X) and treating it with a dilute acid, if necessary, allows for easy hydrolysis and decarboxylation, yielding an α-substituted ester.
Malonic acid ester synthesis is similar to acetoacetic acid ester synthesis.