598-57-2Relevant academic research and scientific papers
Method for preparing methyl-nitramine
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Page/Page column 4-5, (2018/11/22)
The invention discloses a method for preparing methyl-nitramine. According to the method, N,N'-dimethylurea serves as a raw material. The method comprises the following steps: (1) dissolving N,N'-dimethylurea into dichloromethane to prepare a solution, slowly adding the solution into mixed acid composed of concentrated nitric acid having a mass fraction of 98% and 20% of fuming sulfuric acid to carry out nitration reaction at a reaction temperature of 5 DEG C below zero to 0 DEG C, and pouring the reaction mixture into ice water to dilute after charging; (2) heating the diluent obtained in thestep (1) to 5-30 DEG C for carrying out hydrolysis reaction for 30-120 minutes, separating the hydrolytic liquid phase after reaction termination, drying the dichloromethane by using anhydrous magnesium sulfate, and concentrating, thereby obtaining methyl-nitramine. The method disclosed by the invention aims to solve the problems that the reaction operation steps are complicated, N,N'-dimethylurea is incomplete in nitration, the hydrolysis condition is harsh, the yield is low and the like in the methyl-nitramine preparation process. The method is mainly applied to the preparation of methyl-nitramine.
Safe and Convenient Synthesis of Primary N -Nitramines in the Freon Media
Zharkov, Mikhail N.,Kuchurov, Ilya V.,Fomenkov, Igor V.,Tartakovsky, Vladimir A.,Fedyanin, Ivan V.,Zlotin, Sergei G.
supporting information, p. 1103 - 1108 (2017/02/24)
A convenient one-pot synthesis of primary aliphatic N-nitramines, which includes the nitration of available N,N′-dialkyloxalamides or N-alkylcarbamates with dinitrogen pentoxide in the 1,1,1,2-tetrafluoroethane media followed by ammonolysis of intermediate N-nitroamides in the same solvent has been developed. The method is environmentally safe, and affords target N-nitramines in up to 94% overall yield.
Method for producing dinitro-diaza-alkanes and interediate products thereto
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, (2008/06/13)
Method of synthesis of dinitro-diaza-alkanes and intermediate products thereto from alkylamines and esters, whereby a dialkyl ester of a dicarboxylic acid is reacted with an alkylamine in an aqueous medium to form the corresponding dialkyldiamide of the dicarboxylic acid; the resulting dialkyldiamide is nitrated by means of conventional nitration agents to form the corresponding dialkyldinitroamide of the dicarboxylic acid; the resulting dialkyldinitroamide is reacted with methylamine and/or ethylamine in an aquous medium to yield a corresponding alkylnitroamine and the dimethyldiamide and/or diethyldiamide of the dicarboxylic acid, and the alkylnitroamine is isolated from that, and the isolated alkylnitroamine is condensed in a known manner to form the dinitro-diaza-alkanes.
Kinetics and Mechanism of the Hydrolysis of N-Methyl-N-nitroamides in Aqueous Sulphuric Acid
Challis, Brian C.,Rosa, Eduarda,Iley, Jim,Norberto, Fatima
, p. 179 - 183 (2007/10/02)
Pseudo first-order rate constants for the hydrolysis of N-methyl-N-nitroacetamide and various 4-substituted N-methyl-N-nitrobenzamides in sulphuric acid solutions are reported.N-Methyl-N-nitroacetamide undergoes an acid-catalysed process at all acidities studied for which the solvent deuterium isotope effect, k0H2SO4/k0D2SO4, is 0.87, and ΔS(excit.) ca. -85 (+/-10) J K-1 mol-1.These results suggest an AAc2 mechanism involving rapid pre-equilibrium protonation of the substrate followed by rate-limiting attack of water at the carbonyl C-atom to form atetrahedral intermediate which collapses, in a fast step, to the products.The N-methyl-N-nitrobenzamides, however, exhibit both non-catalysed and acid-catalysed hydrolysis.The non-catalysed pathway operates at acidities up to ca. 5 mol dm-3 H2SO4, and is characterised by a solvent deuterium isotope effect, k0H2SO4/k0D2SO4, of 1.5, ΔS(excit.) ca. -100 (+/-10) J K-1 mol-1 and a Hammett ρ value of 1.0 (+/-0.1).No catalysis by Br- is observed and the results are more consistent with a thermal rearrangement and expulsion of N2O.The acid-catalysed pathway operates at acidities >5 mol dm-3 H2SO4.The solvent deuterium isotope effect k0H2SO4/k0D2SO4 is 0.58, ΔS(excit.)>0 JK-1 mol-1 and the Hammett ρ value is -3.4 (+/-0.1).Thus a change in mechanism occurs at ca. 5 mol dm-3 H2SO4 to an Ac1 pathway involving protonation of the substrate, followed by rate-limiting cleavage of the amide C-N bond to form a benzoyl cation.The different acid-catalysed hydrolysis pathways for the N-nitroacetamide and N-nitrobenzamides is ascribed to the stabilisation afforded to the benzoyl cation as opposed to the carbonium ion.N-Nitroamides are hydrolysed exclusively via amide C-N bond cleavage whereas the correspondning N-nitrosoamides decompose via concurrent C-N and N-N (i.e. denitrosation) bond cleavage.This difference between N-nitro and N-nitroso-amides is discussed in terms of the greater stability of the NO+ group.
The Nucleophilic Catalysed Decomposition of N-Methyl-N-nitroamides in Aqueous Buffers
Challis, Brian C.,Rosa, Eduarda,Norberto, Fatima,Iley, Jim
, p. 1823 - 1828 (2007/10/02)
Rate constants for the decomposition of N-nitro-N-methylamides to N-nitro-N-methylamine and the corresponding carboxylic acid in aqueous buffer solutions are reported.For N-nitro-N-methylacetamide (1a) and N-nitro-N-methylbenzamide (1b), the pH-rate profiles indicate that below pH 5 the reaction is independent of +>.At pH values >7 the reactions are strongly HO- catalysed.Moreover, the basic component of the buffer also catalyses the decomposition reaction.Second-order rate constants, kB, for this buffer catalysis are dependent on the structure of the base.Thus Broensted plots of log kB versus base pKa for (1a) and (1b) yield slopes of 0.64 and 0.60, respectively, for nitrogen bases.The oxygen bases AcO-, HPO42- and HO- appear to fall on another line of slope ca. 0.5.Solvent deuterium kinetic isotope effects for both the AcO- and HO- catalysed reactions are ca. 1, whereas that for the non-catalysed reaction is ca. 2.Catalysis is found to be nucleophilic in nature; thus, for each of the reactions of (1b) with morpholine, piperidine and 4-chlorophenol the corresponding benzoylated base could be isolated.Further, the observed first-order rate constants for the reaction of either (1a) or (1b) with imidazole reach a limiting value identical to that for N-acetylimidazole itself.For (1a), the ratios of kB for piperidine to 2,2',6,6'-tetramethylpiperidine and for pyridine to acetate are ca. 300 and 100, respectively.Again, this is consistent with nucleophilic catalysis.The aromatic substituent effect for the HO- catalysed reaction yields a Hammett ρ value +2.8, whereas for the non-catalysed reaction a value of 0.8 is obtained.The data are discussed in terms of a mechanism in which nucleophilic attack of the catalyst at the carbonyl C-atom to form a tetrahedral intermediate is rate-limiting.Lack of 18O-exchange during hydrolysis is consistent with this proposal.This mechanism is unusual for amide hydrolysis and must reflect the enhanced nucleofugacity of the N-nitroamine fragment.The mechanism of the non-catalysed process is less clear.The substituent effects are much smaller than those for HO-, and therefore unlikely to involve attack of H2O at the carbonyl carbon.N-Methyl cleavage via H2O attack or thermal rearrangement are possible candidates.
Thermal decomposition of energetic materials. 30. Thermolysis of energetic metal-nitraminato complexes under conditions that simulate combustion
Palopoli,Brill
, p. 2971 - 2976 (2008/10/08)
The thermal decomposition of six energetic nitraminato complexes of Cu(II), Pd(II) and Ni(II) was investigated at 5°C/min by IR spectroscopy and DSC and at 100°C/s (to simulate combustion) by rapid-scan infrared spectroscopy. The objective was to correlate, insofar as possible, the structure and bonding of the parent complex to the decomposition behavior and products. The metal-nitraminato complexes decompose very rapidly. The gases liberated are farther along toward final combustion products than is the case with most organic nitramines subjected to the same thermal conditions. The thermolysis properties of M-(NH3)2[N(NO2)(CH2) 2N(NO2)] (M = Cu, Pd) complexes can be understood in terms of the relative strengths of the metal-nitrogen bond. Most of the NH3 is retained by the Pd complex in the condensed phase while decomposition occurs, whereas more of the NH3 is released to the gas phase in advance of decomposition by the Cu complex. There is circumstantial evidence that the high potential for forming ·H in the ammine complexes drives the thermolysis farther along toward the final, thermodynamically stable products. The Ni(II) complexes were more difficult to characterize because the thermal stimulus exploded the samples.
SOME PROPERTIES OF UNSATURATED NITROAMINES
Vereshchagin, L. I.,Kirillova, L. P.,Luzgina, G. M.,Gareev, G. A.
, p. 806 - 808 (2007/10/02)
In the reaction of ketovinylnitroamines with various nucleophiles substitution of the nitroamine group by the nucleophilic reagent took place in all cases.The addition of bromine at the double bond of ketovinylnitroamines took place with difficulty after prolonged heating in benzene or carbon tetrachloride.
Syntheses of α-C-Functionalized N-Nitrodialkylamines: Esters of methanol and 1-ethanol
Plesch, Winfried,Wiessler, Manfred
, p. 1494 - 1503 (2007/10/02)
The α-acetoxynitramines 5 and 6 - important derivatives for studying the biological properties of N-nitrodialkylamines 4 - have been synthesized, and the stability of the ester bond has been investigated.The reaction of N-nitroalkylamines 7 with 1-halogenoethyl acetates 9, thought to afford 6, yielded the diazene N-oxides 10 as the main products.
REACTIVITY OF N-NITROENAMINES
Ivshin, V. P.,Smirnov, V. F.,Yashukova, O. A.
, p. 1270 - 1273 (2007/10/02)
The effect of a substituent at the α-carbon atom of the vinyl group in N-nitroenamines on their reactivity is explained by steric hindrances to pN-?C=C conjugation.The acid-catalyzed rearrangement of N-(tert-butylvinyl)-N-methylnitroamine to N-(1-tert-butyl-2-nitrovinyl)-N-methylamine was discovered.Under analogous conditions methyl(vinyl)-N-nitroamine undergoes cleavage to methylnitroamine and acetaldehyde.Unlike unconjugated N-nitroenamines, which are converted into C-nitroenamines when heated, methyl(vinyl)-N-nitroamine undergoes cleavage by a deamination mechanism with the release of nitrous oxide.
