598-57-2Relevant articles and documents
Method for preparing methyl-nitramine
-
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.
Method for producing dinitro-diaza-alkanes and interediate products thereto
-
, (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.
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.
