Trimethyl hydrazinium iodide

Amination of nitroarenes with hydroxylamine, known for over 100 years [43], proceeds undoubtedly according to the VNS mechanism. Modem aminating agents, such as 4-amino-1,2,4-triazole [44—46], sulfenamides [47, 48], and 0-methyl hydroxylamine [49, 50], are more versatile and efficient than hydroxylamine. 1,1,1-Trimethyl hydrazinium iodide proved to be particularly useful for this purpose [51-53]. Amination with this reagent proceeds via addition of the hydrazino moiety followed by a base-induced p-elimination of trimethylamine from the corresponding adducts. 

The known cyclization method of l,l,l,-trimethyl-2-(2 -substituted)ethyl hydrazinium salts to 2-substituted IH-aziridines by treatment with sodium methoxide in methanol cannot be applied for the similar cyclization of l,l,l,-trimethyl-2-(2 -methoxycarbonyl-2 -triethylsilyl) ethyl hydrazinium iodide, since in this case the methoxide mediated cleavage of the carbon-silicon bond occurs preferentially. 

Hydrazinium 2-(l-Methyl-propyli-den)-l, 1,1 -trimethyl- -iodid E14b, 632 (N-Methylier.)... 

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