3-Nitro-9-nitrosocarbazole

Nitrosocarbazole condenses with 9-aminocarbazole to give the azo compound 122, heating of which produces dimers in a ratio similar to that observed by oxidation of carbazole (see Section II,A,2) it was therefore believed to involve the carbazol-9-yl radical. 3-Nitro-9-nitrosocarbazole was shown to serve as a nitrosating agent for A-methylaniline it converted aziridine to ethene and nitrous oxide. ... 

A mixture of 50 g. (0.30 mole) of carbazole and 400 ml. of glacial acetic acid is heated to boiling and then cooled somewhat. Twenty-one grams (0.33 mole) of sodium nitrite is added to the stirred mixture in small portions at such a rate that the temperature of the mixture remains below the boiling point. There is next added, in the same manner as before, 83 ml. of a mixture of equal portions of acetic acid and nitric acid (sp. gr. 1.4). The precipitated crystalline material is filtered off and washed with ethanol. This material is 3-nitro-9-nitrosocarbazole, and it may be further purified by recrystallization from ethanol or ethyl acetate. 

Despite the relative figures for chlorination of 9-acetylcarbazole, electrophilic substitution of 9-acylcarbazoles has been used preparatively to produce 2-nitro- and 2-acylcarbazoles. " 9-Nitrosocarbazole nitrates at C-3. 

Carbazoles normally react with electrophiles to yield the 3-monosubstituted and 3,6-disubstituted derivatives. Further reaction may occur at the 1- and the 8-positions. There is evidence that the initial reaction occurs at the 9-position. Thus, nitrosation of carbazole with sodium nitrite in acetic acid yields 9-nitrosocarbazole which, when treated with nitric acid, is converted into 3-nitrocarbazole (09CB3797) and 3,6-dinitrocarbazoIe (46USP2392067). Direct nitration of carbazole with nitric acid (02GEP128853) or with ethyl nitrate also yields the 3-nitro and 3,6-dinitro derivatives, together with 1,3,6,8-tetranitrocarbazole (27CB738). 

Nitrosation Butyl nitrite. 3-Nitro-N-nitrosocarbazole. Nitrosyl chloride. 

Clark and Heimkamp found that deamination of meso- and d/-2,3-dimethyl-aziridine by reaction with 3-nitro-N-nitrosocarbazole is highly stereospeciflc. The >.vo-isomer (I) afforded c(. -butene-2 of 99.9% purity and the d/-isomer gave 99%... 

Deamination Aryidiazonium hexafluorophosphates. Aryldiazonium tetrahaloborates. Di-fluoroamine. Dinitrogen tetroxide (White). Hydroxylamine-O-sulfonic aeid. Hypophos-phorous acid. 3-Nitro-N-nitrosocarbazole. Nitrosyl chloride. Tetramethylurea. Debenzylation of benzoylamines Triethyloxonium fluoroborate. 

Treatment of an aziridine with nitrosyl chloride, S-nitro-TV-nitrosocarbazole or methyl nitrite leads to the formation of an alkene and nitrous oxide (equation 76) " an intermediate iV-nitroso derivative was isolated at low temperatures. The deamination of cis-and frflBJ-2,3-dimethylaziridine gave the corresponding ds- and fra J-2-butenes with complete stereospecificity in each case. The reaction was found to be first order with respect to the A nitroso intermediate and the transition state was suggested to involve simultaneous cleavage of both C—bonds. A similar decomposition... 

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