Malonic acid is a type of dicarboxylic acid with the structure CH2(COOH)2. Malonates are the ionized form of malonic acid, as well as its salts and esters. An example of a malonate is diethyl malonate which is malonic acid’s diethyl ester. The name malon (μᾶλον) originates from the Greek word meaning ‘apple’.
In 1858, malonic acid was first prepared by the French chemist Victor Dessaignes oxidizing malic acid. Malonic acid is found in some fruits like citrus fruits. Malonic acids can be produced through the fermentation of glucose.
Properties of Malonic Acid
The chemical formula for malonic acid is C3H4O4.
The molar mass for malonic acid is 104.061 g·mol−1.
The density for malonic acid is 1.619 g/cm3.
The melting point for malonic acid is 135 to 137 °C (275 to 279 °F; 408 to 410 K) (decomposes).
Malonic acid decomposes on boiling.
Solubility in Water
The solubility of malonic acid in water is 763 g/L.
pKa1 = 2.83
pKa2 = 5.69
Magnetic susceptibility (χ)
Other related anions
Related carboxylic acids
Carboxylic acids related to malonic acid include:
The IUPAC name for malonic acid is propanedioic acid.
Preparation of Malonic Acid
The laboratory preparation of malonic acid starts with chloroacetic acid which is also known as MCA (monochloroacetic acid). The following steps listed below explain the procedures involved in the preparation of malonic acid.
The first step involves the production of sodium salt by sodium carbonate.
In step two, it is made to react with sodium cyanide.
A salt (cyanoacetic acid salt) is generated through nucleophilic substitution.
In step four, the nitrile group is hydrolyzed with sodium hydroxide to produce sodium malonate.
The final step of the procedure. In this step,the acidification results in malonic acid.
Industrial Preparation of Malonic Acid
Industrially, malonic acid is produced by the hydrolysis of dimethyl malonate or diethyl malonate. It is a forerunner to polyester specialities and it is used to generate countless useful compounds as a construction block chemical.
Uses of Malonic Acid
Malonic acid is a precursor to specialty polyesters i.e it can be converted into 1,3-propanediol for use in polyesters and polymers.
Malonic acid can also be used as a component in alkyd resins, which are used in coating applications for protecting against damage caused by UV light, oxidation, and corrosion.
It is used in various manufacturing processes as a high value specialty chemical including the electronics industry, flavors and fragrances industry, specialty solvents, polymer crosslinking, and pharmaceutical industry.
Malonic acids are used in food and drug industries to control acidity, either as an excipient in pharmaceutical formulation or natural preservative additive for foods.
Malonic acids are used as building block chemicals to produce numerous valuable compounds, including the flavor and fragrance compounds such as gamma-nonalactone, cinnamic acid, and the pharmaceutical compound valproate.
Malonic acids are used in the cross-linking of corn and potato starches to produce biodegradable thermoplastics.
Some companies use malonic acid and its derivatives as a surgical adhesive.
Hazardous Effects of Malonic Acid To The Human Body
Malonic acids cause skin irritation. Ingestion:
It may cause gastrointestinal irritation with nausea, vomiting and diarrhea.
It may be harmful if swallowed
If inhaled it can cause respiratory tract irritation.
Precautions To Take While Handling Malonic Acid
Wash face, hands and any exposed skin thoroughly after handling malonic acids.
Do not eat, drink or smoke when working with malonic acids.
Avoid inhaling gases, fumes, dust, mist, vapor, and aerosols produced by malonic acids.
Avoid contact with skin, eyes, and clothes when handling this acid.
In case of fire and/or explosion do not breathe the fumes because they are poisonous.
Fight fire from a reasonable distance.
Wear self-contained breathing apparatus while working with this acid.
Is malonic acid corrosive?
Yes, Malonic acid is a strong irritant. It is slightly toxic and when dissolved in water it is a strong acid which is corrosive to eyes, skin and respiratory tract.
Is Malonic acid Hazardous?
Yes, Malonic acid causes eye and skin irritation. It may also cause gastrointestinal irritation with nausea, vomiting and diarrhea and can be harmful if swallowed.
What is malonic acid used for?
Malonic acid is used as a precursor in polymers and polyester.
It is used in flavours and fragrance industries.
It is used to control acidity and It is used in the production of pharmaceutical products.
What is the other name for malonic acid?
Another name for malonic acid is dicarboxylic acid.
What foods is malonic acid in?
Malonic acid is seen in different foods such as red beetroots, corn, scarlet beans, common beets, and cow milks.
Is malonic acid strong or weak?
Malonic acid is a medium-strong acid.