3- Cyano-5-nitropyridinium salt

The same type of rearrangement could be observed with 3-cyano-5-nitropyridinium salt (123) when it reacts with methylamine, affording 124... 

Olah s original preparative nitrations were carried out with mixtures of the aromatic compound and nitronium salt alone or in ether, and later with sulpholan as the solvent. High yields of nitro-compounds were obtained from a wide range of aromatic compounds, and the anhydrous conditions have obvious advantages when functional groups such as cyano, alkoxycarbonyl, or halogenocarbonyl are present. The presence of basic fimctions raises difficulties with pyridine no C-nitration occurs, i-nitropyridinium being formed. ... 

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