The Synthesis of Secondary Nitramines by the Nitrolysis of N,N-Disubstituted Amides

Robson, John H.; Reinhart, Joan

doi:10.1021/ja01614a028

Cited by 46 publications

(10 citation statements)

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“…Rate constants at 240 o C, as well as activation energies are given in Table I. For three nitramines, diethylnitramine (DEN), 1,3-dinitro-1,3-diazacyclohexane (mDNP), and RDX, thermolysis rates were compared in benzene and in d 6 -benzene. As was the case for DMN and DIPN, no solvent deuterium kinetic isotope effect (DKIE) was observed, supporting the hypothesis that in the decomposition of these nitramines intermolecular hydrogen transfer is not important.…”

Section: Resultsmentioning

confidence: 99%

Mechanisms of Nitramine Thermolysis

Oxley¹,

Kooh²,

Szekeres³

et al. 1994

J. Phys. Chem.

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The thermal decomposition of a number of nitramines was studied in dilute solution and in the melt.The nitramines included acyclic mononitramines [dimethylnitramine (DMN), diethylnitramine (DEN), dipropylnitramine (DPN), and diisopropylnitramine (DIPN)], cyclic mononitramines [N-nitro-piperidine (NPIP) and N-nitropyrrolidine (NPyr)], cyclic dinitramines [N-dinitropiperazine (pDNP), 1,3-dinitro-1,3-diazacyclopentane (DNI), and 1,3-dinitro-1,3-diazacyclohexane (mDNP)], and 1,3,5-trinitro-1,3,5-triazocyclohexane (RDX), octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine(HMX), hexanitro-hexaazaisowurtzitane (HNIW), and 1,3,3-trinitroazetidine (TNAZ). For the acyclic and cyclic mono-and di-nitramines, the corresponding nitrosamines were the only or major condensed-phase product.Kinetics and activation parameters were determined for the thermolysis of dilute solutions (0.01 to 1.0 wt%) over range 200 o to 300 o C. The thermolyses were found to be first-order with the rate constants unaffected by use of deuterated solvent. As the nitramines became more complex than dimethylnitramine (DMN), the rate of decomposition increased and the product distribution became more complex. As the length of the aliphatic chain increased (DMN < DEN < DPN), the rate of thermolysis increased, yet nitrosamine remained the only observed condensed-phase product. When a secondary carbon was attached to the N-nitramine (DIPN) rather than primary (DPN), the rate of decomposition increased and a new condensed-phase product was observed. Among the cyclic nitramines, the rate of decomposition increased as the number ofNNO 2 groups increased (NPIP < pDNP; NPyr < DNI; mDMP < RDX). The position of the nitramine groups affected the decomposition; meta NNO 2 groups (mDNP) decomposed faster than para (pDNP). Ring strain decreased stability: mDNP < DNI; HMX < RDX. In complex nitramines, the increase in decomposition rate, the appearance of new products, and the change in the relative importance of nitrosamine and of N 2 and N 2 O is attributed to new decomposition routes available to them. However, since complex nitramines (e.g. RDX) maintain first-order kinetics and since most have activation energies in the range of 40 to 50 kcal/mol, it is believed that the triggering mechanism remains N-NO 2 homolysis. Intramolecular hydrogen transfer is also considered an important mode of nitramine decomposition. IntroductionBefore attempting to understand the mechanisms operating in species containing multiple nitramine functionalities, we examined the simple nitramine, dimethylnitramine (DMN).

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Section: Resultsmentioning

confidence: 99%

Mechanisms of Nitramine Thermolysis

Oxley¹,

Kooh²,

Szekeres³

et al. 1994

J. Phys. Chem.

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“…[179] The best yield of the corresponding nitramines 7 was obtainedi nl iquid CO 2 in the presence of concentrated HNO 3 (3 equiv.). Notably,i fasimilarr eaction was performed under neat conditions with N 2 O 5 generated in situ from HNO 3 and (CF 3 CO) 2 O, the yield of 9 waso nly 45 %, [181] which underlines the advantage of the fluid nitration procedure. Notably,i fasimilarr eaction was performed under neat conditions with N 2 O 5 generated in situ from HNO 3 and (CF 3 CO) 2 O, the yield of 9 waso nly 45 %, [181] which underlines the advantage of the fluid nitration procedure.…”

Section: N-nitrationreactionsmentioning

confidence: 92%

“…Under fluid conditions, N,N'-diacetylpiperazine afforded N,N'-dinitropiperazine (9), ac omponent of solid propellants with ar educed burning rate and increased transparency of combustion products, [180] in 95 %y ield. Notably,i fasimilarr eaction was performed under neat conditions with N 2 O 5 generated in situ from HNO 3 and (CF 3 CO) 2 O, the yield of 9 waso nly 45 %, [181] which underlines the advantage of the fluid nitration procedure. However,t he reaction of 1,3,5-triacetylhexahydro-1,3,5-triazine with nitrooleum in aC O 2 mediumproduced the dinitroc ompound 10 (57 %y ield) rather than RDX.T hisr esult contradicts the data presented in the patent, [164] and further studies are clearly neededt oc onfirm the applicability of the fluid nitrolysis methodf or the preparation of RDX and HMX.…”

Section: N-nitrationreactionsmentioning

confidence: 92%

Prospective Symbiosis of Green Chemistry and Energetic Materials

et al. 2017

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A global increase in environmental pollution demands the development of new "cleaner" chemical processes. Among urgent improvements, the replacement of traditional hydrocarbon-derived toxic organic solvents with neoteric solvents less harmful for the environment is one of the most vital issues. As a result of the favorable combination of their unique properties, ionic liquids (ILs), dense gases, and supercritical fluids (SCFs) have gained considerable attention as suitable green chemistry media for the preparation and modification of important chemical compounds and materials. In particular, they have a significant potential in a specific and very important area of research associated with the manufacture and processing of high-energy materials (HEMs). These large-scale manufacturing processes, in which hazardous chemicals and extreme conditions are used, produce a huge amount of hard-to-dispose-of waste. Furthermore, they are risky to staff, and any improvements that would reduce the fire and explosion risks of the corresponding processes are highly desirable. In this Review, useful applications of almost nonflammable ILs, dense gases, and SCFs (first of all, CO ) for nitration and other reactions used for manufacturing HEMs are considered. Recent advances in the field of energetic (oxygen-balanced and hypergolic) ILs are summarized. Significant attention is paid to the SCF-based micronization techniques, which improve the energetic performance of HEMs through an efficient control of the morphology and particle size distribution of the HEM fine particles, and to useful applications of SCFs in HEM processing that makes them less hazardous.

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“…14 The nitration is carried out using nitrating agents that are pre formed 4,6,9,11-14 or generated in situ, for example, from HNO 3 7,15 or its salts 16 and acid an hydrides. 6, 7 The process is usually performed in a large excess of the nitrating agent in an organic solvent, such as acetonitrile, 12 ССl 4 , 9 СН 2 Сl 2 , 11,13 dichloroethane, 17 ace tic acid, 7,15,18 acetic anhydride, 18 which makes the pro cess explosive and fire hazardous. In addition, the reac tion not always proceeds selectively in said systems con taining oxidizing and reducing agents.…”

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confidence: 99%