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
Methyl ethyl ketone peroxide form that is typically quoted in the commercially available material from chemical supply companies. Dilute solutions of 30 to 60% MEKP are used in industry and by hobbyists as the catalyst which initiates the crosslinking of unsaturated polyester resins used in fiberglass, and casting. For this application, MEKP is dissolved in dimethyl phthalate, cyclohexane peroxide, or diallyl phthalate to reduce sensitivity to shock. Benzoyl peroxide can be used for the same purpose. MEKP is a severe skin irritant and can cause progressive corrosive damage or blindness. Methyl ethyl ketone peroxide Methyl ethyl ketone peroxide (MEKP) is an organic peroxide, a