Malonic acid

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Malonic acid
Malonic acid
Chemical name propanedioic acid
Other names methanedicarboxylic acid
Chemical formula C3H4O4
Molecular mass 104.03 g/mol
CAS number [141-82-2]
Melting point 135 - 137 °C decomp.
SMILES O=C(O)CC(O)=O
Properties
Density and phase  ? g/cm3, Solid
Solubility in water Completely Soluble
Melting point 135-136°C (408-409 K)
Boiling point Decomposes
Acidity (pKa1) 2.83
Acidity (pKa2) 5.69
Disclaimer and references

Malonic acid (IUPAC systematic name: propanedioic acid) is a dicarboxylic acid with structure CH2(COOH)2. 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.

Contents

[edit] Biochemistry

The calcium salt of malonic acid occurs in high concentrations in beetroot. Malonic acid inhibits succinate dehydrogenase in the citric acid cycle.

[edit] Organic synthesis

A classical preparation of malonic acid starts from acetic acid [1]. This acid is chlorinated to chloroacetic acid. Sodium carbonate generates the sodium salt which is then reacted with sodium cyanide to the cyano acetic acid salt in a nucleophilic substitution. The nitrile group can be hydrolysed with sodium hydroxide to sodium malonate and acidification affords malonic acid.

[edit] Organic reactions

In a well known reaction malonic acid condenses with urea to barbituric acid. Malonic acid is frequently used as an enolate in Knoevenagel condensations or condensed with acetone to form Meldrum's acid.

[edit] External links

[edit] References

  1. ^ Malonic acid Nathan Weiner Organic Syntheses, Coll. Vol. 2, p.376; Vol. 18, p.50 Online article