Energetic dinitrogen pentoxide

Hydroxy-terminated polybutadiene (8) (HTPB) has been treated with dinitrogen pentoxide in methylene chloride. The product (9) is an energetic oligomer but is unlikely to find application because of the inherent instability of /3-nitronitrates." Initial peroxyacid epoxidation of some of the double bonds of HTPB followed by reaction with dinitrogen pentoxide yields a product containing vtc-dinitrate ester groups and this product (NHTPB) is of much more interest as an energetic binder (see Section 3.10)." ... 

The reaction of 3-hydroxymethyl-3-methyloxetane (42) with dinitrogen pentoxide is an interesting example a short reaction time with 2.46 equivalents of dinitrogen pentoxide producing 3-(nitratomethyl)-3-methyloxetane (NIMMO) (43), an energetic polymer precursor. 

The polymers 1, 3 and 4 were 0-nitrated with nitric acid to give products containing nitrogen contents of 11.6 %, 19.9 % and 9.55 % respectively. Polymer 2, on the other hand, was nitrated with dinitrogen pentoxide in liquid carbon dioxide. Evaluations of these energetic polymers indicate that polymer 1 is a possible candidate for use in insensitive munitions. 

A practical application of dinitrogen pentoxide in methylene chloride reagent involves the nitration of either ammonium carbamate or nitrourethane, followed by ammonolysis to yield ammonium dinitramide, an energetic oxidizer with enormous potential for use in future high performance propellant compositions. This important reaction is discussed in more detail in Chapter 9. 

The nitrolysis of A,A-disubstituted amides is one of the key tools for the synthesis of nitramine containing energetic materials. The present synthesis of the high performance explosive HMX is via the nitrolysis of hexamine (Section 5.15). This is an inefficient reaction requiring large amounts of expensive acetic anhydride. An alternative route to HMX (4) is via the nitrolysis of either l,3,5,7-tetraacetyl-l,3,5,7-tetraazacyclooctane (79) (79%) or 1,5-dinitro-3,7-diacetyl-l,3,5,7-tetraazacyclooctane (80) (98 %) with dinitrogen pentoxide in absolute nitric acid. These reactions are discussed in more detail in Section 5.15. 

A-Picrylazetidine (155) is found to be inert to attack by dinitrogen pentoxide, a consequence of the electron-withdrawing picryl group. The triazine (156) gave a 60 % crude yield of the energetic 1,3-nitramine-nitrate (157) which is an analogue of Tris-X. 

Nitramine-nitrates of general structure (133) are known as NENAs and are conveniently prepared from the nitrative cleavage of A-alkylaziridines " with dinitrogen pentoxide or from the direct nitration of the corresponding aminoalcohols. These compounds find use as energetic plastisizers in explosive and propellant formulations Bu-NENA (R = n-Bu) is a component of some LOVA (low vulnerability ammunition) propellants. ... 

The use of dinitrogen pentoxide in the Ponzio reaction for the oxidation-iutration of oximes to em-dinitro groups has been reported by Russian chemists. Millar and co-workers extensively investigated these reactions and reported the synthesis of 2,4,5,7,9,9-hexanitrofluorene (2), a thermally stable explosive with an oxygen balance better than TNT. Other energetic materials containing gem-dinitro functionality were synthesized from the oximes of acetophenone, 4-nitroacetophenone, a-nitroacetophenone and 2-hydroxyacetophenone. 

The Af-nitration of urea and imide functionality is usually quite difficult compared to the analogous amides. Solutions of dinitrogen pentoxide in nitric acid are frequently employed to synthesize energetic Af, Af -dinitroureas. Yields are often very high and go to completion unlike with many conventional nitrating agents which frequently yield partially nitrated products. Energetic bicycles K-56 (16)" and K-55 (17)" have been prepared from the dihydrochloride salts (14) and (15) respectively. 

Some of the major advances in the synthesis of energetic materials have arisen from the use of dinitrogen pentoxide-nitric acid solutions for nitrolysis reactions. These reactions are important routes to alicyclic, cyclic and caged energetic polynitramines. 

Millar and Philbin ° reported using dinitrogen pentoxide in methylene chloride at subambient temperatures for the nitrodesily lation of silylamines (33) and silylamides. The methodology, which results in nitramines (34), nitramides and nitroureas in excellent yields, is well suited for the synthesis of energetic materials and we believe it will find wide use in the future. 

The reaction of aziridines and azetidine heterocycles with dinitrogen pentoxide in chlorinated solvents yields 1,2-nitramine nitrates and 1,3-nitramine nitrates respectively. In most cases yields are good to excellent, but, reactions are not as general as with the oxygen heterocycles the outcome of reactions is heavily dependent on the nature of the substituent on the exocyclic nitrogen. Some of the products from these reactions find use as melt-castable explosives i.e. Tris-X (46) and energetic plasticizers e.g. Bu-NENA (48) the latter is a component of some LOVA (low vulnerability ammunition) propellant formulations. 

Energetic materials synthesized by using dinitrogen pentoxide (N2O5)... 

Energetic materials synthesized with the use of dinitrogen pentoxide (N2Os) technology. 

Energetic Materials Synthesized Using Dinitrogen Pentoxide... 

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