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
Potassium ethyl xanthate as the anhydrous salt and is nonhygroscopic. Potassium ethyl xanthate is used in the mining industry as flotation agent for extraction of the ores of copper, nickel, and silver. The method exploits the affinity of these "soft" metals for the organosulfur ligand. Potassium xanthate is a useful reagent for preparing xanthate esters from alkyl and aryl halides. The resulting xanthate estes are useful intermediates in organic synthesis. The LD50 is 683 mg/kg (oral, rats) for potassium ethyl xanthate. Potassium ethyl xanthate Potassium ethyl xanthate (KEX) is an organosulfur compound with the chemical formula CHCHOCSK. It is a pale yellow powder