The interaction of molecular oxygen with aminophenols mediated by metal copper and copper compounds

Several copper compounds (Cu, Cu2O, CuO, CuCl and CuCl2) have been used as catalysts for the oxidation of 2-, 3- and 4-aminophenol with O2 at 25 °C; a comparison of their activities was made through kinetic determinations. The oxidation of 2-aminophenol selectively produced 2-amino-phenoxazin-3-one (1), whereas the oxidation products of 3- and 4-aminophenol were two new compounds, 2-amino-5 [(3-hydroxyphenyl) amino]-2,5-cyclohexadiene-1,4-dione (3) and 3-[(4-hydroxyphenyl)amino]-4-[(2-amino-5-hydroxy) phenyl]-6-[(4-hydroxyphenyl)imino]-2,4-cyclohexadien-1-one (2)