Ethyl cyanohydroxyiminoacetate Ethyl cyanohydroxyiminoacetate Ethyl cyanohydroxyiminoacetate (oxyma) is the oxime of ethyl cyanoacetate and finds use as an additive for carbodiimides, such as dicyclohexylcarbodiimide (DCC) in peptide synthesis. It acts as a neutralizing reagent for the basicity or nucleophilicity of the DCC due to its pronounced acidity (pKa 4.60) and suppresses base catalyzed side reactions, in particular racemization. Ethyl cyanohydroxyiminoacetate is obtained in the reaction of ethyl cyanoacetate and nitrous acid (from sodium nitrite and acetic acid) in 87% yield. Because of the rapid hydrolysis of the ester, the reaction should be carried out at pH 4.5, in buffered phosphoric acid the
Ethyl cyanoacetate This reactivity is similar to that of esters of malonic acid. As an example of reactivity at the nitrile, diethyl malonate is obtained from cyanoacetic acid ethyl ester by reaction with ethanol in the presence of strong acids. Heating in the presence of sodium ethoxide forms the dimeric 3-amino-2-cyano-2-pentendiaciddiethylester. Due to its functionality cyanoacetate reacts: Ethyl cyanoacetate is a building block for the synthesis of heterocycles which are used for example as drugs: Also many other functional heterocycles are in good yields accessible from ethyl cyanoacetate, such as 3-substituted coumarin derivatives. Non-cyclic products from this starting material include: Ethyl cyanoacetate