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 ammonia. These esters are white, crystalline solids at room temperature. Except for the phenyl carbamate, they sublime at moderate temperatures; methyl carbamate sublimes at room temperatures. The first two and ethyl carbamate are very soluble in water, benzene, and ether. These other carbamates (methyl, butyl, and phenyl) are only used in small quantities for research purposes. the dipole moment is in error. The published dipole moment is 2.59 D ref. J. Amer. Chem. Soc., [1961], 83, 4596. 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