Olga V. Serushkina

New aryloxy-substituted condensation polymers

Abstract Large family of new aromatic diamines containing aryloxy side groups was developed. All the diamines were obtained on the basis of 2,4,6-trinitrotoluene (TNT) — very cheap and available explosive material. TNT was converted into 1,3,5-trinitrobenzene (TNB); subsequent aromatic nucleophilic nitro-displacement reactions led to mono- and diaryloxy-substituted mono- and dinitrobenzenes which were converted into the final aryloxy-substituted diamines. Interaction of the diamines obtained with aromatic dicarboxylic acids chlorides and aromatic tetracarboxylic acids dianhydrides led to the formation of new aryloxy-substituted polyimides and polyimides combining high thermal properties with solubility in organic solvents.

New condensation aromatic polymers containing phenoxy, thiophenoxy, and phenylsulphone side groups

Abstract New condensation monomers—primarily diamines containing phenoxy, thiophenoxy and phenylsulphone substituents were obtained from 2,4,6-trinitrotoluene (TNT). Interaction of some dinitro compounds containing strong electron-withdrawing groups in meta -positions with bis-phenols under conditions of aromatic nucleophilic polynitro substitution reactions led to the formation of aromatic oligoethers. Based on aromatic diamines containing phenoxy and thiophenoxy substituents under conditions of traditional polycondensation and polycyclo condensation reactions, aromatic polyamides and polyimides demonstrating improved processability combined with high thermal stability were obtained.

Synthesis of 1- and 5-(pyrazolyl)tetrazole amino and nitro derivatives

Regioselective introduction of nitro groups was studied in the case of pyrazoles containing a 1- or 5-tetrazole substituent at position 3(5). All the possible isomeric C-mononitropyrazoles were synthesized. The reduction of these compounds gave the respective 3(5)-amino-5(3)-tetrazolylpyrazoles, which were nitrated to 3(5)-nitramino-4-nitro-5(3)-tetrazolylpyrazoles. The reaction of 1-(nitropyrazol-3(5)-yl)tetrazoles with hydroxylamine-O-sulfonic acid produced the respective N-amino derivatives.

Nitro group substitution in 2,4,6-trinitrotoluene under the action of arenethiols and transformations of the reaction products

The reactions of 2,4,6-trinitrotoluene with arenethiols in the presence of inorganic bases in dipolar aprotic solvents led to the replacement exclusively of the ortho-nitro group to form 2-arylthio-4,6-dinitrotoluenes. Substitution, oxidation, and reduction of the latter and their transformation products provided the basis for the preparation of mono- and di-ortho-S-substituted nitrotoluenes and aminotoluenes. Factors favoring the regiospecificity of ortho-substitution in 2,4,6-trinitrotoluene are discussed.

Regioselective replacement of nitro groups in 2,4,6-trinitrotoluene under the action of alkanethiols. Synthesis of ortho-(alkylthio)-substituted nitrotoluenes and their oxidation to sulfoxides and sulfones

The reactions of 2,4,6-trinitrotoluene with alkanethiols in the presence of K2CO3 (the molar ratio of the reactants is 1 : 1 : 1) in dipolar aprotic solvents result in selective replacement of the ortho-nitro group to form 2-alkylthio-4,6-dinitrotoluenes, which can be oxidized to the corresponding sulfoxides or sulfones. The second ortho-nitro group can be replaced under the action of one more equivalent of alkanethiol on sulfides as exemplified in PhCH2SH.

Synthesis of 1-(N-nitropyrazolyl)-1Н-tetrazoles – a new type of heteronuclear N-nitropyrazole derivatives

A general method has been developed for the synthesis of 1-pyrazolyl-1Н-tetrazoles, and N-nitration of these compounds was studied. The structural features affecting the direction of nitration were identified. A series of 1-(N-nitropyrazolyl)-1Н-tetrazoles was obtained, representing a new type of heteronuclear N-nitropyrazole derivatives.

Replacement of the nitro groups in 1,3,5-trinitrobenzene through the action of phenols; a general method for preparation of 3,5-dinitrophenyl aryl ethers and 5-nitroresorcinol diaryl ethers

3,5-Dinitrophenyl aryl ethers (3,5-DNPAE) and 5-nitroresorcinol diaryl ethers inaccessible yet. At the same time, these compounds may be considered, for example, to be potential pesticides 1,2 and also as the starting compounds for preparing novel monomers for polycondensation. We found a method for preparing 3,5-DNPAE based on nucleophilic substitution of a nitro group in 1,3,5trinitrobenzene (TNB) through the action of phenols containing both electron-donating and electron-withdrawing substituents in an amide type dipolar aprotic solvent* (DMF, N-methylpyrrolidone, tetramethylurea, etc.). The reaction occurs in the presence of bases (K2CO 3 is the most efficient) at 80--90 ~ over a period of 4--8 h. Using 2-naphthol and 3-pyridinol as examples we showed that not only phenols, but also other aromatic hydroxy compounds can be used. Phenols incorporating two hydroxy groups (hydroquinone, 2,2-bis(4-hydroxyphenyl)propane) can be involved in this reaction (TNB : Ar(OH)2 2 : 1). The reaction yields the corresponding bis-3,5-dinitrophenyl ethers.

New procedure for nucleophilic sulfonation of aromatic nitro compounds: Destructive oxidation of S-arylthioglycolic acids esters

A new reaction was discovered: oxidative destruction of sulfides of ArSCH2CO2Me type to sulfonic acids ArSO3H effected by 70% HNO3. This reaction was used to introduce an SO3H group instead of aromatic nitro group activated only by meta-substituents: At treating with HSCH2CO2Me + K2CO3 the NO2 group was substituted to form ArSCH2CO2Me with subsequent transformation into ArSO3H. p-Fluoronitrobenzene behaved similarly (with replacement of the fluorine).

Reactions of 1,3,5-trinitrobenzene with primary aliphatic alcohols

Analysis of reactions of 1,3,5-trinitrobenzene (TNB) with alcoholates of primary aliphatic alcohols (substitution of the nitro group or generation of σH-complexes at the unsubstituted position of TNB) leads to the conclusion that high basicity of alcoholates (MeONa, EtONa) of unsubstituted primary alcohols promotes formation of σH-complexes, thus preventing nucleophilic substitution of a nitro group. Introduction of electron-withdrawing substitutes (R = HC≡C, H2C = CH, pyridyl) into the alcohol molecule (RCH2OH) reduces the basicity of their alcoholates which makes substitution of nitro groups possible aff ording the corresponding 1-alkoxy-3,5-dinitrobenzenes in the presence of K2CO3 in N-methylpyrrolidone at 80 °C.

Azasydnone – Novel 'green' building block for designing high energetic compounds

The discovery of novel explosophoric building blocks for the construction of energetic compounds is extremely rare. Here, based on the comparative experimental properties and computational analysis of compounds where nitroaryl backbones were bonded with various nitrogen/oxygen-rich groups, it is shown that compounds having the azasydnone group possess higher density, detonation performance and thermal stability than their corresponding nitro, azido and tetrazole-analogs. All of these properties, as well as the oxygen balanced content of the “green” nitrogen rich endothermic unit make them an attractive explosophoric building block in the field of energetic materials chemistry.