Oxygen Absorption by the Ternary System Amine-Styrene Epoxide-Acid

Aromatic amines are widely used as inhibitors of radical oxidation reactions. During the search for a trap for the radical species involved in the oxidation of the styrene epoxide (SE)-ptoluenesulfonic acid (TSA) binary system (BS) with oxygen (1), we found that the addition of a strong inhibitor, α�naphthy� lamine to the BS(SE + TSA) being oxidized accelerates rather than suppresses the absorption of oxygen. The extension of the range of objects demonstrated that all of the tested aromatic amines—p�, o�, and mami� nophenols—accelerate oxidation when being added to the BS(SE + TSA). The simplest aromatic amine, aniline, being introduced in the system, also sharply accelerates the oxidation of the binary system. The acceleration effect is clearcut in the absence of TSA in a joint solution of amines and epoxide in the pres� ence of glacial acetic acid, i.e., this is a rather general phenomenon. The results of investigation of this phe� nomenon are presented below.