Amine oxidation and the chemistry of quinone imines. Part III. 2,4-Di-methoxy-5-t-butylaniline

Abstract

The oxidation of 2,4-dimethoxy-5-t-butylaniline (1) by silver oxide, and by potassium ferricyanide in sodium hydroxide and in sodium hydrogen carbonate, has been examined. Besides 2,2′,4,4′-tetramethoxy-5,5′-di-t-butyl-azobenzene (2), a high yield of 3,8-dimethoxy-2,7-di-t-butylphenazine (3) and small quantities of 8-methoxy-2,7-di-t-butyl-3H-phenoxazin-3-one (4) result. The structure of the latter has been proved by synthesis from 2,5-dimethoxy-4-t-butylaniline and 4-methoxy-5-t-butyl-o-benzoquinone. Condensation of the latter quinone with (1) gives the isomeric phenoxazone (12). These reactions exemplify a new synthesis for phenoxazones. Other products isolated from the oxidation of the aniline (1) are the p-quinone (5), the quinone imine (7), and the two N-aryl-p-quinone imines (6) and (8).