Malonic acid
Encyclopedia : M : MA : MAL : Malonic acid
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| Chemical name | |
| Other names | methanedicarboxylic acid |
| Chemical formula | |
| Molecular mass | |
| CAS number | |
| Melting point | decomp. |
| SMILES | |
| Properties | |
| Density and phase | ? g/cm3, Solid |
| Solubility in water | Completely Soluble |
| Melting point | 135-136°C (208-209 K) |
| Boiling point | Decomposes |
| Acidity (pKa1) | 2.83 |
| Acidity (pKa2) | 5.69 |
| [Chemical infoboxDisclaimer and references] | |
Malonic acid (IUPAC systematic name: 1,3-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.
Biochemistry
The calcium salt of malonic acid occurs in high concentrations in beetroot. Malonic acid inhibits succinate dehydrogenase in the citric acid cycle.Organic synthesis
A classical preparation of malonic acid starts from acetic acid [#endnote_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.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.External links
References
- ↑ Malonic acid Nathan Weiner Organic Syntheses, Coll. Vol. 2, p.376; Vol. 18, p.50 [Online article]
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