Rates of formation of some phenazines by cyclization of di- and monoimines of N-(2-aminophenyl)-p-benzoquinone

Abstract

0.34 ppm and yielded 4 on hydrolysis. A dimer, 5, with a longer retention time was also identified on the basis of its spectra.By comparison of proton and 13C NMR spectra from three different Grignard reagent samples, the reagent prepared from 3, and the reagent prepared from 6 before and after heating, it was possible to make assignments of methyl proton resonance signals and to assign all of the significant 13C resonances. The methyl proton resonances are reproduced in Figure 1. In the Grignard reagent prepared from 3, the sharp resonance at 0.84

Characterization of 3-Aminophenazin-2-ol Isolated from the Chemical Oxidation of o-Phenylenediamine

“…The fraction obtained in the organic layer is identified as 2,3-phenazinediamine, 1 . The 1 H NMR spectrum of this product is identical with material obtained from an independent synthesis . After neutralizing the aqueous layer and collecting the resulting precipitate, 3-aminophenazin-2-ol, 2, is isolated.…”

“…The 1 H NMR spectrum of this product is identical with material obtained from an independent synthesis. 7 After neutralizing the aqueous layer and collecting the resulting precipitate, 3-aminophenazin-2-ol, 2, is isolated. The singlet resonance at 6.89 ppm in 1, attributed to the 1 and 4 aromatic protons, has been split into two peaks in 2 (6.92 and 7.16 ppm), indicating the molecule is not symmetric.…”

“…Previous reports describe the synthesis of 2,3-phenazinediamine 7 and 2,3-phenazinediol 12 in high yield by combining OPD with 1,4-benzoquinone or 2,5-dihydroxy-1,4-benzoquinone, respectively. We have completed this sequence by isolating and characterizing the mixed member of the series, 3-aminophenazin-2-ol, in good yield.…”

Azine Dyes

“…LOVELESS, BROWN, and HORROCKS [2] investigated spectrophotometrically the formation of the phenazine ring via cyclization of N-(2-aminophenyl)-p-benzoquinonediimine 3, the oxidation product of 2,4 0 -diaminodiphenylamine 2. In the pH range 6 -9, the amino group adds intramolecularly to the quinone ring, and 2-aminophenazine 4 is formed by oxidation.…”

Azine Dyes

“…Oxazine dyes are prepared by the former procedure, thiazine dyes by the latter, and phenazine dyes by both. Loveless, Brown, and Horrocks [2] investigated spectrophotometrically the formation of the phenazine ring via cyclization of N-(2-aminophenyl)-p-benzoquinonediimine 2, the oxidation product of 2,4 -diaminodiphenylamine 2.…”