Nitramine-nitrate explosives

A number of nitramine-nitrate explosives have been prepared by Millar and co-workers from the action of dinitrogen pentoxide on aziridines and azetidines (Section 5.8). Millar and co-workers used their aziridine ring-opening nitration methodology (Section 5.8.1) to synthesize the high performance melt-castable nitramine-nitrate explosive known as Tris-X... 

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. 

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 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. 

See 2,4,6-Trinitrophenyl-(l-methylol)propyl-nitramine Nitrate] 7)A.D.Little,Inc, Report on Study of Pure Explosive Compound, Cambridge,Mass,.v 4(1952) Compd No 305, p 586(Part of rept is unclassified)... 

This change in editorial leadership has resulted, perhaps inevitably, in a change in editorial policy which is reflected in the contents of Volume 8. there has been a marked de-emphasis on the inclusion of organic parent compounds followed by an exhaustive and voluminous cataloging of azide, azido, azo, diazido, diazonium, diazo, nitro, dinitro, polynitro, nitramine, nitrate (esters and salts), dinitrate, polynitrate, nitroso, polynitroso, chlorate, perchlorate, peroxide, picrate, etc, derivatives - regardless of whether any of these derivatives exhibit documented explosive or energetic properties. Only those materials having such properties have been included in this volume... 

EC reduction has been used extensively in the detection of residues of nitro-aromatic, nitramine, and nitrate explosives at pendent Hg, Au amalgam or glassy carbon electrodes - the forensic evaluation of this subject has been reviewed. " The methodology described may be applicable to drugs and other compounds containing these functional groups. 

Trifluoroacetaldehyde figures in recent work on the synthesis of analogues of nitramine-type explosives, having been used to prepare 2,2,2-trifluoro-1,1-dinitraminoethane (20) by application of the route used to procure Medina itself [CHj(NHNOj)2] (Scheme 19), and to obtain the 2,4,6-tris(trifluoromethyl) derivative (22) of RDX (Scheme 20). Nitration of 2,4,6-tris(trifluoromethyl)hexahydro-sym-triazine (21) yields the heterocyclic nitramine (22) directly. The acetamido-analogue [CF3-CH(NH COMe)2] of the bisformamide (19a) can be prepared by heating anhydrous trifluoroacetaldehyde with acetamide, and the trifluoroacetamido-compound... 

CHEMICAL SENSITISATION IN NITRO, NITRAMINE AND NITRATE EXPLOSIVES... 

Sensitisation in Nitro, Nitramine and Nitrate Explosives", accepted for inclusion in "The Ninth Symposium (International) on Detonation, to be held 28th August -1st September 1989, Portland, Oregon, USA. 

Nitramine production, 17 164 Nitrate analysis, of water, 26 38 Nitrated products, as explosives, 17 162 Nitrate ore bed, 22 844 Nitrate-reducing conditions, defined, 3 757t... 

Walsh ME. Determination of nitroaromatic, nitramine, and nitrate ester explosives in soil by gas chromatography and electron capture detector. Talanta 2001 54 427-438. 

Some explosives are not volatile enough to be analyzed via GC the relatively high temperatures required can cause decomposition of some explosives (e.g., nitrate esters, nitramines) excessive contamination often present in hand swabs from postexplosion debris can interfere with optimum performance of some detectors... 

Yinon, J. Mass Spectrometry of Explosives Nitro Compounds, Nitrate Esters, and Nitramines. Mass Spectrom. Rev. 

The chemical structures of some common mifttary explosives are shown in Figure 1. These include the nitrate esters such as nitrocellulose (NC), NG, EGDN, and (PETN) nitroarenes such as trinitrotoluene (TNT, CH3—C6H2(N02)3), picric acid (HO—C5H2(N02)3), and 2,4,6-trinitrophenylmethylnitramine (tetryl) and nitramines such as RDX (C3H6N6O6), HMX (C4H8N8O8), and hexanitrohexa-azaisowurtzitane (CL— 20). Of these, only CL— 20 is new , that is, less than 50 years old [3]. Mixtures of oxidizers and fuels, such as AN and FO (called ANFO), are also secondary explosives. 

As stated above, nitrate esters (such as NG or PETN) and nitramines (such as RDX or HMX), form nitrite ions under alkahne conditions and therefore can be detected by the Griess reaction. However, the Griess spot test by itself does not enable to distinguish between individual explosives within these groups. 

The DPA test is another common spot test for nitrate esters and nitramines [1, 3, 4, 50-55]. The reagent (1% DPA in concentrated sulfuric acid) is oxidized in the presence of these explosives, producing a deep blue color. 

The following examples illustrate the range of apphcations of LC/MS for trace analysis of explosives ESI-LC/MS/MS-CID fragmentation processes of a series of nitroaromatic, nitramine and nitrate ester explosives were studied in the negative-ion mode using daughter-ion, parent-ion and neutral loss scans [14]. Table 1 shows the CID daughter ions in ESI-MS/MS of TNT. 

Several additives were tested with a series of explosives in order to enhance ESI intensities [15—17]. Nitramine and nitrate ester explosives showed enhanced response for ammonium nitrate additive, by forming [M + NOs] adduct ions in the negative-ion mode. Nitrate adduct ions were more intense than trifluoroacetate (TFA) or chloride adduct ions by a factor of 6-40. The base peak in the negative-ion mass spectrum of TNT, with 1 mM ammonium nitrate in the mobile phase was at m/z 226 due to the [M-H] ion. 

X. Xu, A.M. van der Craats and P.C.A.M. de Bmyn, Highly sensitive screening method for nitroaromatic, nitramines and nitrate ester explosives by high performance liquid chromatography — atmospheric pressure ionization — mass spectrometry (HPLC-APl-MS) in forensic applications , J. Forensic Sci., 49 No. 6 (2004) 1171-1180. 

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. 

A number of secondary high explosives containing both nitramine and nitrate ester functionality have been reported. Aliphatic examples include A-nitrodiethanolamine dinitrate (DINA) (110), prepared from the nitration of diethanolamine with nitric acid-acetic anhydride in the presence of zinc chloride,and A,A -dinitro-A,A -bis(2-hydroxyethyl)oxamide dinitrate (NENO) (111), prepared from the mixed acid nitration of A,lV -bis(2-hydroxyethyl) oxamide . 

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