Search results
Results from the WOW.Com Content Network
Diethyl malonate, also known as DEM, is the diethyl ester of malonic acid. It occurs naturally in grapes and strawberries as a colourless liquid with an apple-like odour, and is used in perfumes. It is also used to synthesize other compounds such as barbiturates, artificial flavourings, vitamin B 1, and vitamin B 6.
Malonic acid is a dicarboxylic acid with structure CH 2 (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 μαΎ¶λον (malon) meaning 'apple'.
In 1879, the French chemist Édouard Grimaux synthesized barbituric acid from malonic acid, urea, and phosphorus oxychloride (POCl 3). [9] Malonic acid has since been replaced by diethyl malonate, [10] [11] because using the ester avoids the problem of having to deal with the acidity of the carboxylic acid and its unreactive carboxylate.
Unlike other malonic esters that are derived via malonic ester synthesis, diethyl phenylmalonate is typically indirectly derived via a Claisen condensation with diethyl oxalate and ethyl phenylacetate followed by decarbonylation. [2]
An ester of a carboxylic acid. R stands for any group (typically hydrogen or organyl) and R ′ stands for any organyl group. In chemistry, an ester is a compound derived from an acid (organic or inorganic) in which the hydrogen atom (H) of at least one acidic hydroxyl group (−OH) of that acid is replaced by an organyl group (R ′). [1]
On heating, the di-ester undergoes thermal decarboxylation, yielding an acetic acid substituted by the appropriate R group. [1] Thus, the malonic ester can be thought of being equivalent to the − CH 2 COOH synthon. The esters chosen are usually the same as the base used, i.e. ethyl esters with sodium ethoxide.
Dimethyl malonate is a diester derivative of malonic acid. It is a common reagent for organic synthesis used, for example, as a precursor for barbituric acid. It is also used in the malonic ester synthesis. It can be synthesized from dimethoxymethane and carbon monoxide. [2]
The use of aldehyde in the name comes from its history: aldehydes are more reactive than ketones, so that the reaction was discovered first with them. [ 2 ] [ 3 ] [ 4 ] The aldol reaction is paradigmatic in organic chemistry and one of the most common means of forming carbon–carbon bonds in organic chemistry .