Aberrant S(RN)1 Reaction of 4-Aminophenol with alpha,p-Dinitrocumene: EPR Observation of Intermediates.

The tert-butoxide-induced substitution of alpha,p-dinitrocumene by 4-aminophenol unexpectedly afforded the N-coupled product, 2-(4-hydroxyanilino)-2-(4-nitrophenyl)propane. EPR observations revealed arylaminyl radical intermediates as well as coupled anion radicals, hence the normal S(RN)1 process may compete with an alternative nonchain reaction pathway.

Cyclic voltammetry of phenazines and quinoxalines including mono- and di-N-oxides. Relation to structure and antimicrobial activity.

Cyclic voltammetry data were obtained for eight phenazines and phenazine-N-oxides, and eleven quinoxalines and quinoxaline-N-oxides: 1,6-phenazine-diol-5,10-dioxide (iodinin), iodinin copper complex, 6-methoxy-1-phenazinol-5,10-dioxide 1,6-dimethoxyphenazine-5-oxide, 1,6-phenazinediol, 1,6-dimethoxyphenazine, quinoxaline-1,4-dioxide, 2-methylquinoxaline-1,4-dioxide, 2,3-diphenylquinoxaline-1,4-dioxide, 2-carboxyquinoxaline-1,4-dioxide, 5-hydroxyquinoxaline-1,4-dioxide, 5-hydroxy-8-methoxyquinoxaline-1,4-dioxide, 2-methylquinoxaline, 2,3-diphenylquinoxaline, 5-hydroxyquinoxaline, 5-hydroxy-8-methoxyquinoxaline and 2-(2-quinoxalinylmethylene)hydrazine carboxylic acid methyl ester-1,4-dioxide (Carbadox). The di-N-oxides exhibit the most positive E1/2 values within each class. Reversible first wave reductions were observed for iodinin, iodinin copper complex, 1,6-dimethoxyphenazine-5-oxide, 1,6-dimethoxyphenazine, quinoxaline-1,4-dioxide, 2-methylquinoxaline-1,4-oxide and 2,3-diphenylquinoxaline-1,4-dioxide.

Charge transfer in the mechanism of drug action involving quinoxaline di-N-oxides.

Cyclic voltammetry data were obtained for various 2,3-disubstituted quinoxaline di-N-oxides: dimethyl, bishydroxymethyl, bisacetoxymethyl, bis-N-anilinomethyl, and dicarboxaldehyde hydrate. The dimethyl derivative exhibited the most negative E1/2 value, and along with the diol, showed reversible reduction for the first wave. Rationalizations of the E1/2 values are provided.