1961 年 81 巻 6 号 p. 861-864
Nitration of 1-methylphenazine 5-oxide (I) with potassium nitrate and sulfuric acid at a low temperature gives a mononitro compound (II), m. p. 210°. Refluxing of (II) with methanolic potassium hydroxide results in substitution of the nitro group with methoxyl and 1-methyl-x-methoxyphenazine 5-oxide (III) is formed. Polarization effect of the N-oxide group in (I) is assumed to appear at 3-, 7-, and 9-positions and synthesis of 1-methylphenazines with the methoxyl in 3-, 7-, or 9-position was attempted.
The Wohl-Aue reaction of p-anisidine and m-nitrotoluene afforded 1-methyl-7-methoxyphenazine (VI), m. p. 147°, and its N-oxide (VII), m. p. 182°. The same reaction of o-anisidine and m-nitroanisole gave (VII) and 1-methyl-9-methoxyphenazine (IX), m. p. 164°, that of o-anisidine and m-nitrotoluene afforded (I) alone, and the reaction of o-nitroanisole and m-toluidine, (IX) alone. (VI) and (IX) did not agree with 1-methyl-x-methoxyphenazine (IV), m. p. 152°, obtained by deoxygenation of (III). Condensation of 3-methyl-4-nitroanisole and aniline was attempted in order to obtain a 3-methoxy compound but the objective compound was not obtained. Consequently, (IV) cannot be compared directly but it was assumed to be a 1-methyl-3-methoxy derivative since it did not agree with either of the known samples of 1-methoxy-6-methyl- and 1-methoxy-4-methylphenazines.