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 iodide excellent ethylating agent. It is also used as the hydrogen radical promoter. Ethyl iodide is prepared by using red phosphorus, absolute ethanol and iodine ; the phosphorus and iodine dissolve in the ethanol, where they form phosphorus triiodide, which must be formed "in situ" because it is unstable. During the process the temperature is controlled. The crude product is purified by distillation. Ethyl iodide Ethyl iodide (also iodoethane) is a colorless, flammable chemical compound. It has the chemical formula CHI and is prepared by heating ethanol with iodine and phosphorus. On contact with air, especially on the effect of light,