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 carbamate Ethyl carbamate Ethyl carbamate (also called urethane) is an organic compound with the formula CHCHOC(O)NH. It is an ester of carbamic acid. It is a white solid. Despite its name, it is not a component of polyurethanes. Because it is a carcinogen, it is little used, but has been detected in alcoholic beverages. It is produced industrially by heating urea and ethyl alcohol. It arise also by the action of ammonia on ethyl chloroformate. Ethyl carbamate has been used as an antineoplastic agent and for other medicinal purposes, but this application ended after it was discovered to be carcinogenic in