Malonic acid

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Malonic acid
Identifiers
CAS number141-82-2 YesY
PubChem867
ChemSpider844 YesY
DrugBankDB02175
ChEBICHEBI:30794 YesY
ChEMBLCHEMBL7942 YesY
Jmol-3D imagesImage 1
Properties
Molecular formulaC3H4O4
Molar mass104.06 g mol−1
Density1.619 g/cm3
Melting point135–136 °C
Boiling pointdecomposes
Solubility in waterMiscible
Acidity (pKa)pKa1 = 2.83[1]
pKa2 = 5.69[1]
Related compounds
Other anionsmalonate
Related carboxylic acidsacetic acid
oxalic acid
propionic acid
tartronic acid
acrylic acid
butyric acid
succinic acid
fumaric acid
Related compoundspropanone
propionaldehyde
propanedial
dimethyl malonate
Hazards
MSDSExternal MSDS
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references
 
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Malonic acid
Identifiers
CAS number141-82-2 YesY
PubChem867
ChemSpider844 YesY
DrugBankDB02175
ChEBICHEBI:30794 YesY
ChEMBLCHEMBL7942 YesY
Jmol-3D imagesImage 1
Properties
Molecular formulaC3H4O4
Molar mass104.06 g mol−1
Density1.619 g/cm3
Melting point135–136 °C
Boiling pointdecomposes
Solubility in waterMiscible
Acidity (pKa)pKa1 = 2.83[1]
pKa2 = 5.69[1]
Related compounds
Other anionsmalonate
Related carboxylic acidsacetic acid
oxalic acid
propionic acid
tartronic acid
acrylic acid
butyric acid
succinic acid
fumaric acid
Related compoundspropanone
propionaldehyde
propanedial
dimethyl malonate
Hazards
MSDSExternal MSDS
 YesY (verify) (what is: YesY/N?)
Except where noted otherwise, data are given for materials in their standard state (at 25 °C (77 °F), 100 kPa)
Infobox references

Malonic acid (IUPAC systematic name: propanedioic acid) is a dicarboxylic acid with structure CH2(COOH)2. The ionized form of malonic acid, as well as its esters and salts, are known as malonates. For example, diethyl malonate is malonic acid's diethyl ester. The name originates from the Greek word μᾶλον (malon) meaning 'apple'.

Biochemistry[edit]

The calcium salt of malonic acid occurs in high concentrations in beetroot. It exists in its normal state as white crystals. Malonic acid is the classic example of a competitive inhibitor: It acts against succinate dehydrogenase (complex II) in the respiratory electron transport chain.

Preparation[edit]

A classical preparation of malonic acid starts from chloroacetic acid:[2]

Synthesis of malonic acid.png

Sodium carbonate generates the sodium salt, which is then reacted with sodium cyanide to provide the cyano acetic acid salt via a nucleophilic substitution. The nitrile group can be hydrolyzed with sodium hydroxide to sodium malonate, and acidification affords malonic acid.

Organic reactions[edit]

In a well-known reaction, malonic acid condenses with urea to form barbituric acid. Malonic acid is also frequently used as an enolate in Knoevenagel condensations or condensed with acetone to form Meldrum's acid. The esters of malonic acid are also used as a CH2COOH synthon in the malonic ester synthesis.

References[edit]

External links[edit]