Malonic acid is a dicarboxylic acid with structure CH2(COOH)2. The form of malonic acid, as well as its and salts, are known as malonates. For example, diethyl malonate is malonic acid's Ethyl group ester. The name originates from the Greek language word μᾶλον ( malon) meaning 'apple'.
Malonic acid was first prepared in 1858 by the French chemist Victor Dessaignes via the oxidation of malic acid.
Hermann Kolbe and Hugo Müller independently discovered how to synthesize malonic acid from propionic acid, and decided to publish their results back-to-back in the Chemical Society journal in 1864. This led to priority dispute with Hans Hübner and Maxwell Simpson who had independently published preliminary results on related reactions.
Sodium carbonate generates the sodium salt, which is then reacted with sodium cyanide to provide the sodium salt of cyanoacetic acid via a nucleophilic substitution. The nitrile group can be hydrolysis with sodium hydroxide to sodium malonate, and acidification affords malonic acid. Industrially, however, malonic acid is produced by hydrolysis of dimethyl malonate or diethyl malonate. It has also been produced through fermentation of glucose.
It is used in a number of manufacturing processes as a high value specialty chemical including the electronics industry, flavors and fragrances industry, specialty solvents, polymer crosslinking, and pharmaceutical industry. In 2004, annual global production of malonic acid and related diesters was over 20,000 metric tons. Potential growth of these markets could result from advances in industrial biotechnology that seeks to displace petroleum-based chemicals in industrial applications.
In 2004, malonic acid was listed by the US Department of Energy as one of the top 30 chemicals to be produced from biomass.
In food and drug applications, malonic acid can be used to control acidity, either as an excipient in pharmaceutical formulation or natural preservative additive for foods.
Malonic acid is used as a building block chemical to produce numerous valuable compounds,Hildbrand, S.; Pollak, P. Malonic Acid & Derivatives. March 15, 2001. Ullmann's Encyclopedia of Industrial Chemistry including the flavor and fragrance compounds gamma-nonalactone, cinnamic acid, and the pharmaceutical compound valproate.
Malonic acid (up to 37.5% w/w) has been used to cross-link corn and potato starches to produce a biodegradable thermoplastic; the process is performed in water using non-toxic catalysts. Starch-based polymers comprised 38% of the global biodegradable polymers market in 2014 with food packaging, foam packaging, and compost bags as the largest end-use segments.
Eastman Kodak company and others use malonic acid and derivatives as a surgical adhesive.
Additionally, the coenzyme A derivative of malonate, malonyl-CoA, is an important precursor in Cytosol fatty acid biosynthesis along with acetyl CoA. Malonyl CoA is formed there from acetyl CoA by the action of acetyl-CoA carboxylase, and the malonate is transferred to an acyl carrier protein to be added to a fatty acid chain.
Malonic acid is the classic example of a competitive inhibitor of the enzyme succinate dehydrogenase (complex II), in the respiratory electron transport chain. It binds to the active site of the enzyme without reacting, competing with the usual substrate Succinic acid but lacking the −CH2CH2− group required for dehydrogenation. This observation was used to deduce the structure of the active site in succinate dehydrogenase. Inhibition of this enzyme decreases cellular respiration. Since malonic acid is a natural component of many foods, it is present in mammals including humans.
Structure and preparation
Reactions
Briggs–Rauscher reaction
Knoevenagel condensation
In this, the so-called Knoevenagel condensation, malonic acid condenses with the carbonyl group of an aldehyde or ketone, followed by a decarboxylation.
When malonic acid is condensed in hot pyridine, the condensation is accompanied by decarboxylation, the so-called Doebner modification.
Preparation of carbon suboxide
The transformation is achieved by warming a dry mixture of phosphorus pentoxide () and malonic acid. It reacts in a similar way to malonic anhydride, forming malonates.
Applications
Pathology
Biochemistry
Salts and esters
External links
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