The mechanism of the formation and hydrolysis of cyclohexanone oxime in aqueous solutions

The rate of formation of cyclohexanone oxime from cyclohexanone and hydroxylamine and the rate of the reverse reaction, the hydrolysis of cyclohexanone oxime, were studied in the pH range 1–7. The relative position and the bell shape of the two experimental reaction-rate curves can be fully explained by supplementing the reaction mechanism proposed by Jencks for the oximation only with the reverse reaction, applying the principle of microscopic reversibility. An essential part of this mechanism is the intermediate formation of a 1:1 adduct of cyclohexanone and hydroxylamine. It is concluded that the concentration of this adduct is negligibly small under all the conditions used here.