Mannich condensation reactions nitramines

A large number of nitramine-based explosives have been synthesized via Mannich-type condensation reactions (Section 5.13.2). The amines generated from these reactions often have the powerful electron-withdrawing trinitromethyl or fluorodinitromethyl groups positioned on the carbon a to the amino group. This reduces amine basicity to an extent that A-nitration becomes facile. The energetic nitramines (17), (19) and (21) have been synthesized from the condensation of ethylenediamine with 2,2,2-trinitroethanol, 2-fluoro-2,2-dinitroethanol with ethanolamine, and 2-fluoro-2,2-dinitroethylamine with 2,2-dinitro-l,3-propanediol respectively, followed by A-nitration of the resulting amine bases (16), (18) and (20), respectively. 

Primary nitramines react with amines in the presence of an aldehyde to form 1,3-amino-nitramines in a reaction analogous to the Mannich condensation. In these reactions the amine and aldehyde component combine to form an intermediate imine which is then attacked by the nitramine nucleophile. 

Mannich condensations involving polyamines or polynitramines are more complex, and in the case of linear dinitramines, leads to very interesting and diverse chemistry, enabling the synthesis of many cyclic nitramine products. The reaction of methylenedinitramine (168) with various primary amines in the presence of formaldehyde leads to l,5-dinitro-l,3,5,7-tetraazacyclooctanes the 3,7-dimethyl analogue (186) is isolated when methylamine is used. ... 

The use of primary nitramines in Mannich reactions is an important route to numerous secondary nitramines. However, a far more common route to such nitramines involves the Mannich condensation of a terminal gem-dinitroalkane, formaldehyde, and an amine, followed by IV-nitration of the resulting polynitroalkylamine. The preformed methylol derivative of the gem-dinitroalkane is often used in these reactions and so formaldehyde can be omitted. This route has been used to synthesize explosives like (92) and (209). ... 

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See also in sourсe #XX -- [ , ]

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