Description
Diethyl malonate is an organic compound, belonging to the diethyl ester of malonic acid, naturally present in guava, melon, grapes, pineapple, blackberry and strawberry, and is a colorless liquid with an apple smell. Due to its natural pleasant smell, it is a common flavoring ingredient in perfumes, artificial flavors, alcoholic beverages, various wines and spirits. It is also an essential intermediate in the synthesis of many drugs, such as barbiturates, vitamins B1 and B6, and non-steroidal anti-inflammatory drugs. In addition, diethyl malonate is also involved in the organic synthesis of other compounds, such as α-aryl malonates, monosubstituted and disubstituted acetic acids. It can react with benzaldehyde to produce diethylbenzylidene malonate in the Knoevenagel condensation reaction.
Uses
Diethyl malonate is the diethyl ester of malonic acid. It occurs naturally in grapes and strawberries and is widely used in the manufacture of drugs, antioxidants and dyes.
Diethyl malonate is used in organic synthesis for the preparation of α-aryl malonates, mono- and di-substituted acetic acids, barbiturates, and artificial flavors. It is also involved in the synthesis of drugs such as chloroquine, butazoline, and barbiturates. It is an intermediate for vitamin B1, vitamin B6, nonsteroidal anti-inflammatory drugs, agrochemicals, and perfumes. In the Knoevenagel condensation reaction, it reacts with benzaldehyde to give diethylbenzylmethylene malonate.
Description
Diethyl malonate is a diester derivative of malonic acid, a dicarboxylic acid with two carboxyl groups (-COO-) separated by a methylene group (-CH2-). Diethyl malonate is formed by the replacement of the hydroxyl group (-OH) of malonic acid by an ethoxy group (-OCH2CH3). The hydrogen atom on the methylene carbon between the two carboxyl groups makes the compound acidic. Due to its unique structure, diethyl malonate is reactive and can be used as an organic synthesis reagent and in the manufacture of products such as barbiturates, pigments, and agrochemicals. Volatile esters have a fruity aroma and are often used as spices and flavoring agents. Diethyl malonate is a volatile diester that occurs naturally in fruits such as grapes, strawberries, guavas, melons, pineapples, and blackberries.
Chemical properties
Diethyl malonate has a light, pleasant aromatic odor.
Occurrence
It has been reported to be found in pineapples, bilberries, cape gooseberries, brandy, malt whiskey, apple brandy, grape brandy, port wine, cider, sherry, red wine, white wine, strawberry wine, and bilberry wine.
Uses
Diethyl malonate occurs naturally in grapes and strawberries. It is used in the preparation of barbiturates, artificial flavors, vitamin B1 and vitamin B6, and perfumes.
Uses
Manufacturing of barbiturates.
Uses
Diethyl malonate is used in organic synthesis for the preparation of α-aryl malonates, mono- and di-substituted acetic acids, barbiturates, and artificial flavors. It is also used in the synthesis of drugs such as chloroquine, butazoline, and barbiturates. It is an intermediate in the synthesis of vitamin B1, vitamin B6, nonsteroidal anti-inflammatory drugs, agrochemicals, and perfumes. In the Neuvengel condensation reaction, it reacts with benzaldehyde to form diethylbenzylidene malonate.
Definition
ChEBI: Ethyl malonate is a dicarboxylic acid.
Preparation
Chloroacetic acid is reacted with sodium cyanide to form cyanoacetic acid, followed by saponification; the malonate is finally esterified by azeotropic distillation with ethanol in benzene
Taste threshold
Taste characteristics at 50 ppm: sweet and fruity, with notes of apple and pineapple.
Overview
Diethyl malonate is the diethyl ester of malonic acid. Acylation of diethyl malonate with magnesium chloride and triethylamine has been reported. Diethyl malonate reacts with various substituted 1,2-propadienones in a 1,4-addition reaction catalyzed by K 2 CO 3 to form multifunctionalized β,γ-unsaturated enones.
Safety Overview
Slightly toxic if ingested. Irritating to skin. Flammable liquid when exposed to heat or flame; may react with oxidizing materials. Fire can be extinguished with water, foam, carbon dioxide, dry powder. When heated to decompose, it releases acrid fumes and irritating gases. See also esters.
Metabolism
When esters were fed to chicks at a 5% dietary level, 32% of the energy in diethyl malonate was available (Yoshida et al., 1970). Hydrolysis of diethyl malonate produces ethanol and malonic acid, a relatively strong acid that acts as an enzyme inhibitor, including succinate dehydrogenase (Fassett, 1963). Malonate injected into rats or rabbits is excreted mostly unchanged, but also results in increased excretion of citrate and a-ketoglutarate (Krebs, Salvin & Johnson, 1938). Some malonate may be metabolized via the tricarboxylic acid cycle, decarboxylated to acetate, and then converted to succinate, which has been detected in rat urine (Lee & Lifson, 1951). Diethyl malonate is hydrolyzed by adipose tissue lipase (Lynn & Perryman, 1960) and by α-chymotrypsin to the monoester (Cohen & Crossely, 1964). It is oxidized to 34% in 110 minutes by homogenized mycelium of Streptomyces nitrotonis grown on carbamate (Schatz, Trelawny, Schatz & Mohan, 1957).
Purification method
If too impure (IR, NMR), heat the ester (250 g) with anhydrous ethanol (125 mL) and concentrated sulfuric acid (75 mL) on a steam bath for 36 h and then fractionate under reduced pressure. Otherwise, fractionate under reduced pressure and collect the steady boiling intermediate fractions