Nitramine anion

Reaction of nitramine anions RNNOf with benzyl halides occurs pre dominantly at nitrogen. The O/N product ratio is enhanced to approximately unity when harder electrophiles (e.g., EtOCH2Cl) are the reaction partners... 

Mannich bases derived from polynitroalkanes are usually unstable because of the facile reverse reaction leading to stabilized nitronate anions. The nitration of Mannich bases to nitramines enhances their stability by reducing the electron density on the amine nitrogen through delocalization with the nitro group. The nitration of Mannich bases has been exploited for the synthesis of numerous explosives, some containing both C-NO2 and N-NO2 functionality. Three such compounds, (163), (164) and (165), are illustrated below and others are discussed in Section 6.10. 

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. 

The anions of primary nitramines, like other nucleophiles, can undergo Michael 1,4-addition reactions with a range of a,-unsaturated substrates to form secondary nitramines of varying molecular complexity (Equation 5.18). Kissinger and Schwartz prepared a number of secondary nitramines from the condensation of primary nitramines with a,/3-unsaturated ketones, esters, amides and cyanides. In a standard experiment a solution of the primary nitramine and... 

Displacements with azido anion are tolerant of many pre-existing explosophoric groups but the nitrate ester group readily undergoes displacement as seen for the synthesis of bis(2-azidoethyl)nitramine (13) from Ai-nitrodiethanolamine dinitrate (12) (DINA). " ... 

In acidic aqueous buffers, secondary nitramines [116] show a six-electron po-larographic wave which is converted into two two-electron waves above pH 5 (Fig. 11.4). Nitrosamines [117,118] show a four-electron wave in acid solution and this becomes a single two-electron wave above pH 5 (Fig, 11,5). Above pH 5 the halfwave potentials are independent of pH. Primary nitramines are relatively acidic. They show a six-electron wave in acidic aqueous buffers, the height of which falls to zero around the pKg value for the nitramine because the anion is not reducible [119],... 

The corresponding V-nitro derivatives behave similarly306-308 in acid solution the hydrazines are produced in a six-electron reaction, in alkaline medium the first two-electron reduction results in the formation of the A7-nitroso derivatives which at a more negative potential are further reduced. iV-Nitropyrazole behaves slightly differently as the reduction in acid solution also results in a cleavage of the N-N bond with formation of nitrous acid. 2-Nitraminopyri-dine309 in acid solution is reduced to the hydrazine. In alkaline solution the anion is reducible, in contradistinction to most nitramines derived from primary amines. The four-electron reduction yields 2-aminopyridine. Pyridine 1-nitroimide is reduced to pyridine.309... 

In alkaline solution most A-nitro derivatives of primary amines form an irreducible anion [R-bHSf02] , with nitraminopyridines as exceptions [205], whereas nitramines of secondary amines are reduced in two steps. [202]. The first reduction consumes 2F/mol and produces an A-nitrosamine. It is noteworthy that A-nitrosamines in alkaline solution are more difficult to reduce than the corresponding A-nitramines it seems to be the only class of nitro compounds in which the nitro group is more easily reducible than the nitroso group. 

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