Abstract
Stability of 1, 2-dimethyl-3-phenyl-4-imidazolidinone (IMO-1) was examined kinetically. It was found that IMO-1 was decomposed to α-methylaminoacetanilide and acetaldehyde in acidic media by the pseudo-first order reaction. In neutral and alkaline media, these products were also formed but the equilibrium between these three compounds was readily established. The pH-profile of decomposition rate constants showed a bell-shape pattern which had a maximum value between pH 5 and 6. The reverse reaction rate was enhanced by the increase of basicity and, therefore, decomposition of IMO-1 decreased. The inflexion point of pH-profile corresponded to the pKa value of IMO-1 (3.8) in acidic region. It was suggested that the reaction rates were influenced by the ionic nature of the compound in solution.
