Sodium nitrotetrazolate

Our new method of isolating sodium nitrotetrazolate dihydrate produces material in high yield, without the intermediate handling of sensitive explosive compounds. This produced NaNT is of sufficient purity for the preparation of DBX-1 of the quality that is required to replace lead azide. However, it does appear that the DBX-1 used as a seed crystal in the synthesis of DBX-1 influences the behavior of the end product. 

CAUTION Sodium nitrotetrazolate dihydrate is an energetic material with sensitivity to various stimuli. Particular care should be taken to not excessively dry the material, as anhydrous NaNT is considerably more sensitive than the dihydrate. While we encountered no issues in the handling of this material, proper protective measures (face shield, ear protection, body armor, Kevlar gloves, and earthened equipment) should be used at all times. 

Sodium Nitrotetrazolate Dihydrate (NaNT) Anhydrous aminotetra-zole (8.48 g, 0.10 mol) and copper sulfate pentahydrate (0.2 g, 0.8 mmol) were added to a solution of nitric acid (9 mL, 65 %) in distilled water (60 mL). This was added to a pre-cooled solution of sodium nitrite (20.8 g, 0.30 mol) and cupric sulfate pentahydrate (11 g, 0.044 mol) in distilled water (100 mL). The solution was maintained at 15 to 18 °C during the addition by means of a cool water bath. After addition, the solution was stirred for 30 min at the same temperature... 

Figure 11.30 Reaction setup for multistep synthesis of sodium nitrotetrazolate.

An acidified solution of the sodium salt was allowed to evaporate during 3 days and spontaneously exploded 2 weeks later. The nature of the explosive species, possibly the aci-tetrazolic acid, was being sought [1]. The silver and mercury salts are explosive [2], The chemical properties of the free nitrotetrazole have been studied. The sodium salt tetrahydrate loses water above 50°C, greatly increasing its friction and shock sensitivity [3],... 

Preparation of High Purity Sodium 5-Nitrotetrazolate (NaNT) An Essential Precursor to the Environmentally Acceptable Primary Explosive, DBX-1... 

Abstract. Sodium 5-nitrotetrazolate dihydrate (NaNT) is a useful precursor compound for the synthesis of lead-free primary explosives however, currently employed syntheses for the compound are tedious, dangerous, and plagued by impurities. Through comprehensive analysis, we elucidate the identity of the most detrimental impurities and further report an improved procedure for preparation of NaNT, which greatly improves the purity, while avoiding the handling of acid cop-... 

Preparation of High Purity Sodium 5-Nitrotetrazolate (NaNT)... 

Nitrotetrazole is readily prepared from the diazotization of 5-aminotetrazole in the presence of excess sodium nitrite and is best isolated as the copper salt complex with ethylenediamine. The salts of 5-nitrotetrazole have attracted interest for their initiating properties. The mercury salt is a detonating primary explosive. The amine salts of 5-nitrotetrazole are reported to form useful eutectics with ammonium nitrate. ... 

Aminotetrazole (91) reacts with potassium permanganate in excess aqueous sodium hydroxide to yield the disodium salt of 5-azotetrazole (92). 5-Azotetrazole is unstable and attempts to isolate it by acidification yields 5-hydrazinotetrazole (93). Diazotization of 5-aminotetrazole (91) in the presence of excess sodium nitrite yields 5-nitrotetrazole (94), a powerful explosive whose mercury and silver salts are primary explosives. ... 

Mercuric-5-nitrotetrazole [Structure (2.13)] was prepared according to the methods reported by Gilligan et al. [14] and Redman and Spear [15]. Thus, 5-aminotetrazole was treated with sodium nitrite and copper sulfate to obtain Cu(NT)2HNT-4H20 (where NT nitrotetrazole). The copper salt was subsequently converted to the ethylene diamine complex MNT was then obtained by treating the complex with mercuric nitrate in HN03 medium. The precursors and final product were air dried. The synthesis of these compounds is carried out in a fume hood behind a protective polycarbonate shield in a stainless steel reaction vessel. 

Preparation of sodium-5-nitrotetrazole dihydrate The diazotization of 5-ami-notetrazole monohydrate (AT) in the presence of excess of sodium nitrite and copper sulfate gives a complex cupric salt intermediate [Cu(NT)2 HNT-4H20] which is then converted to the sodium salt [NaNT-2H20]. 

Preparation of BNCP by acidifying CTCN with aqueous perchloric acid (3%) and then adding a solution of sodium-5-nitrotetrazole dihydrate drop by drop. 

Sodium 5-nitrotetrazole dihydrate which is recrystd twice from w and three times from acet and then air dried is used to prepare a standard curve Uses ... 

Nitro-l,2,4-triazolone, 0712 Nitroacetaldehyde, 0759 2-Nitroethanol, 0867 2-Nitroethanonitrile, 0707 Nitromethane, 0455 5-Nitrotetrazole, 0386 Potassium 1-nitroethoxide, 0802 Potassium 2,5-dinitrocyclopentanonide, 1841 Sodium 5-nitrotetrazolide, 0544... 

C NMR spectra of tetrazolate anions are similar to the spectra of 2-substituted tetrazoles. For instance, the chemical shift of the signal of tetrabutylammonium tetrazolate in CDCI3 is 149.8 ppm <2001JOC3291 >, and for the sodium 5-nitrotetrazolate in acetone- it is 167.5 ppm <2006MI631>. 

The diazotization of 5-aminotetrazole as a general preparative method for 5-substituted tetrazoles with versatile simple substituents is still important. For instance, the preparation of N-unsubstituted 5-nitrotetrazole 397 through 5-nitrotetrazole sodium salt tetrahydrate <1997RJ01771> is a significant achievement of the last decade and demonstrates new features of the amino group reactivity in 5-aminotetrazole derivatives (Scheme 46). 

Caution 5-Nitrotetrazole sodium salt (tetrahydrate) when heated to temperatures higher than 50 °C loses water molecules. The anhydrous salt has high sensitivity to impact and friction. 

Nucleophilic substitution of the diazo group is practically the only method for the production of nitro derivatives of tetrazole [392, 436 143], 5-Nitrotetrazole itself was isolated and identified in the form of metallic salts [436-440, 442, 443], The mechanism of substitution of the diazo group by a nitro group in heterocyclic compounds has not been studied specially. As already mentioned, in many cases the reaction takes place as catalytic nucleophilic substitution and does not require the use of a catalyst (copper salts) [392,444], The results from investigation of the kinetics of the substitution of the diazonium group by the nitro group in compounds of the benzene series make it possible to suppose that the diazonitrite is formed intermediately and quickly reacts with a second nitrite anion [392,444], Some difference between the kinetics of the reaction of 3-diazonium-5-carboxy-l,2,4-triazole and 3-diazonium-5-methoxycarbonyl-l,2,4-triazole with sodium nitrite in hydrochloric acid and the analogous process in the benzene series is probably due to prototropic... 

Another environmentally compatible primary explosive is copper(I) 5-nitrotetrazolate (Fig. 1.17). This compound has been developed under the name of DBX-1 by Pacific Scientific EMC and is a suitable replacement for lead azide. DBX-1 is thermally stable up to 325 °C (DSC). The impact sensitivity of DBX-1 is 0.04 J (ball-drop instrument) compared with 0.05 J for LA. The compound is stable at 180 °C for 24 hrs in air and for 2 months at 70 °C. DBX-1 can be obtained from NaNT and Cu(I)Cl in HC1/H20 solution at a higher temperature. However, the best preparation for DBX-1 in a yield of 80-90 % is shown in the following equation where sodium ascorbate, NaC6H706, is used as the reducing agent ... 

Light and heat and can cause decomposition. May react violently or form sensitive explosive compounds with 2-butyne-l,4-diol, fluoroacetylene, a-nitroguanidine, 5-nitrotetrazol, and others. Incompatible with ammonia, hydrozoic acid, methyl isocyanoacetate, sodium acetylide, sodium peroxyborate, trinitrobenzoic acid, urea nitrate. 

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