A. G. Korepin

Standard enthalpies of formation of certain nitro compounds

Summary1.A thermochemical study has been made of 22 nitro and fluoronitro-containing organic compounds. Their standard enthalpies of combustion and formation have been determined.2.The contribution of certain groups and interactions to the value of ΔHf° of the nitro compounds in the condensed state have been calculated.3.Feasibility has been demonstrated for the calculation of standard enthalpies of formation of nitro and fluoronitro-containing substances by the group contribution method.

Energetic properties and impact sensitivity of crystalline explosives

The impact sensitivity of some groups of nitrates and cubane derivatives has been correlated with their heat of explosion and chemical structure. These correlations show the ways of reducing explosion hazard in handling these compounds. It is currently impossible to construct a reference series of compounds that would allow explosives with preset sensitivity to be synthesized on the basis of a preliminary energetic prediction. New opportunities to enhance safety in handling explosives can be provided by investigating their detonation ability.

N-Substituted tetrahydro-1,3-oxazines and oxazolidines. 1. A new version of the Mannich reaction involving amino alcohols

A new version of the Mannich reaction involving amino alcohols (3-aminopropan-1-ol and aminoethanol) was developed. These compounds react with formaldehyde and CH or NH acids to give N-substituted tetrahydro-1,3-oxazines or oxazolidines.

Preparation and properties of N-fluoro- and N-nitrobis(2,2,2-trinitroethyl)ureas

Fluorination and nitration of bis(2,2,2-trinitroethyl)urea has given the novel N-fluoro-bis(2,2,2-trinitroethyl)urea and N-nitro-bis(2,2,2-trinitroethyl)urea. The thermal decomposition rates and parameters for bis(2,2,2-trinitroethyl)urea and its derivatives have been found, and the standard enthalpies of combustion, and the standard enthalpies of formation of these compounds calculated therefrom, have been determined.

Aminomethylation of 4,4-bis(chloromethyl)oxazolidin-2-one and 4,4-bis(acetoxymethyl)oxazolidin-2-one

N-Aminomethylation of 4,4-bis(chloromethyl)oxazolidin-2-one with formaldehyde and secondary amines is accompanied by the intramolecular ring closure to give 7a-chloromethyl3-oxohexahydroimidazo[1,5-c]oxazol-6-ium chlorides. In the case of the closely related 4,4-bis(acetoxymethyl)oxazolidin-2-one, only N-aminomethylation occurs.

Synthesis and aminomethylation of some heterocyclic α-nitroxyalkyl NH acids

The recently discovered synthetic route to quaternary ammonium salts of a new series via N-aminometylation of 4,4-bis(nitroxymethyl)oxazolidin-2-one was extended to other NH acids obtained for the first time by O-nitration of known a-hydroxyalkyl derivatives of 4-methyloxazolidin-2-one, pyrrolidin-2-one, and benzimidazole. In the aminomethylation of these NH acids, dimethylamine and morpholine were used as the amine components.

Kinetics of the thermal decomposition of bis(2,2-dinitropropyl)-N-fluoroamine

The kinetics of the thermal decomposition of bis(2,2-dinitropropyl)-N-fluoroamine are studied in the liquid phase. The reaction is autocatalytic in a melt. In dilute solution, the reaction rate is described by the first-order law. It is tens of times faster in polar sulfolan than in weakly polar dimethyl phthalate. A mechanism of the decomposition involving the formation of a cyclic transition state at the first, limiting stage of the process is suggested.

Preparation and properties of secondary amides of 1,1-dinitroalkanecarboxylic acids

The previously unknown secondary amides of 1,1-dinitroalkanecarboxylic acids were prepared by the reaction of polynitroimidoyl fluorides with water in the presence of mineral acids. They are inert with respect to electrophiles, but react with nucleophiles with the cleavage of the C-C bond between the carbonyl C atom and the C atom of the dinitromethylene group. An X-ray structural study of the amides was carried out and their thermochemical characteristics were determined.

Reactions of N-methylolnitramines in acid media

1. The direction of the transformations of N-hydroxymethylnitramines in acid medium depends both on the acidity of the medium and on the electronegativity of the substituent on the amino group. 2. Depending on the acidity of the medium, N-hydroxymethylnitramines with moderate electron-acceptor substituents on the amino group are converted to either symmetrical ethers or methylenedinitramines. The latter are the end transformation products of such N-hydroxymethylnitramines in strongly acid media. 3. Independent of the acidity of the medium, N-hydroxymethylnitramines with strong electron-acceptor substituents on the amino group form only the symmetrical ethers.

Synthesis of tetrahydroimidazo[1,5-c]oxazol-3-ones by aminomethylation of some oxazolidinones

Aminomethylation of 4,4-bis(nitrooxymethyl)oxazolidin-2-one and 4,4-bis(chloromethyl)-oxazolidin-2-one utilizing primary amines as the amino components yielded 6,7a-substituted tetrahydroimidazo[1,5-c]oxazol-3-ones.