Aromatic nitramines, synthesis

Aromatic nitramines undergo a rearrangement in which the nitro group migrates to the benzene ring. Such a rearrangement is believed to occur in the synthesis of tetryl, which is made by the nitration and nitrolysis... 

While we believe our discussions of nitramine and nitrate ester synthesis to be comprehensive, it would be quite impossible to have a comprehensive discussion of aromatic nitration in this short chapter - published studies into aromatic nitration run into many tens of thousands. The purpose of this chapter is primarily to discuss the methods used for the synthesis of polynitroarylene explosives. Undoubtedly the most important and direct method for the synthesis of polynitroarylenes involves direct electrophilic nitration of the parent aromatic hydrocarbon. This work gives an overview of aromatic nitration but the discussion doesn t approach mechanistic studies in detail. Readers with more specialized interests in aromatic nitration are advised to consult several important works published in this area which give credit to this important reaction class.The use of polynitroarylenes as explosives and their detailed industrial synthesis has been expertly covered by Urbanski in Volumes 1 and 4 of Chemistry and Technology of Explosives ... 

Nitrations of aromatic amines often involve the intermediate formation of N-nitramines, although these are rarely seen under the strongly acidic conditions of mixed acid nitration (Section 4.5). N,2,4,6-Tetranitro-N-methylaniline (tetryl) is an important secondary high explosive usually synthesized from the nitration of N,N-dimethylaniline or 2,4-dinitro-N-methylaniline. ° The synthesis of tetryl is discussed in Section 5.14. 

The oxidation of aryl diazoates with oxidants like hypochlorite, permanganate and ferri-cyanide anion has seen some limited use for the synthesis of nitramines. This method finds use for the synthesis of arylnitramines where aromatic ring nitration is not required and so excludes the use of standard nitrating agents. 

Dihydropyrrolopyridines are valuable intermediates for the synthesis of pyr-rolopyridines substituted in the six-membered ring. For example, 2,3-dihydropyrrolo[2,3-6]pyridine is converted, via the nitramine (74), into its fully aromatic 5-nitro and 5-amino derivatives. Alternatively, after protection of the secondary amine, the 5- and 6-hydroxy derivatives may be prepared (Scheme 25) (59JA743). 

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