2.6- diamino-3,5 -dinitropyridine-1 -oxide

The direct nitration of 2,6-diaminopyridine (168) with mixed acid yields 2,6-diamino-3,5-dinitropyridine (ANPy) (173). Oxidation of ANPy (173) with peroxyacetic acid yields ANPyO (174) (calculated VOD 7840 m/s, d = 1.88 g/crc ) C-Amination of ANPyO (174) with hydroxylamine hydrochloride in aqueous base yields the triamine (175), an impact insensitive explosive of high thermal stability. ... 

Diamino-2,6-dinitropyridine-N-oxide (DADNPO) is more heat resistant than HNS but its performance is equal to HNS. It is used for oil-well completions at higher depth than HNS shaped charges. 

Due to its enhanced jr-deficiency 3,5-dinitropyridine has a lower site selectivity and it can be expected that oxidative amino-dehydrogenations will take place at all three positions 2, 4, and 6. This has indeed been found. 3,5-Dinitropyridine gives a complex mixture of 2-amino-, 2,6-diamino-, 2,4-diamino-, and 2,4,6-triamino-3,5-dinitropyridines (Scheme 5) (85JOC484, 93ACS95). Mixtures of diamino- and triamino-3,5-dinitropyridines have also been found in the oxidative amination of 2-R-3,5-dinitropyridines (R = NH2, OH, Cl, OMe) and 4-R-3,5-dinitropyridines (R = NH2, Cl). 

Along these lines 3,5-dinitro-2,4,6-triaminopyridine has been obtained by oxidative amination of 2,6-diamino-3,5-dinitropyridine (96JHC895) (Scheme 6). 

Apart from FOX-7, only one of the energetic molecules in this Ust, 1,3,5-triamino-2,4,6-trinitrobenzene (TATB, 3), is already estabhshed as an important, widely used explosive. Two of the others, 2,6-diamino- (35) and 2,4,6-triamino-3,5-dinitropyridine N-oxide (36), and have been aroimd for 10-15 years and have yet to become widely used. This is in part because they are not much better than TATB in terms of explosive properties and thermal stability. One molecule which does promise to be significantly better than TATB is 2,6-diamino-3,5-dinitropyrazine 1-oxide (37). This has only relatively recently appeared on the scene and has yet to be fully investigated. 

---