N-Aryl Benzimidazole and Benzotriazole Derivatives and Their Hybrids as Cytotoxic Agents: Design, Synthesis and Structure-Activity Relationship Studies.

The era of chemotherapy began in the 1940s, which is the basis of traditional antitumor approaches and, being one of the most high-tech treatment methods, is still widely used to treat various types of cancer. A promising direction in modern medicinal chemistry is currently the creation of hybrid molecules containing several pharmacophore fragments of different structures. This strategy is successfully used to increase the therapeutic efficacy of cytotoxic agents and reduce side effects.

Pseudo Four-Component Synthesis of 5,6-Dihydroindolo[2,1-]isoquinolines.

An easy synthesis of novel highly functionalized 5,6-dihydroindolo[2,1-]isoquinolines was developed via a pseudo four-component domino reaction of 1-aroyl-3,4-dihydroisoquinolines, terminal α,β-ynones, and malononitrile. The selective formation of this biologically relevant heterocyclic core was achieved using a one-pot approach under microwave irradiation. The formation of the same skeleton through the reaction of 5,6-dihydropyrrolo[2,1-]isoquinolines with malonic acid dinitrile supports the proposed mechanism, involving the intermediate product of the three-component reaction.

A novel fluorescent sensor for diammonium and metal ions based on a supramolecular charge-transfer complex of bis(aza-18-crown-6)-containing dienone.

A bis(aza-18-crown-6)-containing 2,5-di(benzylidene)cyclopentanone and a bis(ammoniopropyl) derivative of 1,2-di(4-pyridyl)ethylene in MeCN were found to form a supramolecular charge-transfer complex, which can act as an "off-on" fluorescent sensor for the Ca and 1,12-dodecanediammonium ions. The molecular structure of this complex in solution was studied by density functional theory calculations.

Thermal Rearrangement of 5-(2-Hydroxy-6-oxocyclohexyl)-5-chromeno[2,3-]pyridines.

Some of the most important transformations in organic chemistry are rearrangement reactions, which play a crucial role in increasing synthetic efficiency and molecular complexity. The development of synthetic strategies involving rearrangement reactions, which can accomplish synthetic goals in a very efficient manner, has been an evergreen topic in the synthetic chemistry community. Xanthenes, pyridin-2(1)-ones, and 1,6-naphthyridines have a wide range of biological activities.

Solvent-Involved Synthesis of 5--Substituted 5-Chromeno[2,3-]pyridines.

Chromeno[2,3-]pyridines are substances demanded in medicinal and material chemistry. (pot, atom, and step economy) and in particular approaches are key green chemistry techniques that are applied for the synthesis of heterocyclic compounds. In this case, the approach was extended with 'component economy', as solvent was used also as reactant (solvent-involved reaction).

Oxidative Cyclization of 5-Chromeno[2,3-]pyridines to Benzo[]chromeno[4,3,2-][1,6]naphthyridines, Their NMR Study and Computer Evaluation as Material for LED.

Oxidative cyclization is one of the most significant reactions in organic synthesis. Naphthyridine derivatives are often used as luminescence materials in molecular recognition because of their rigid planar structure and as new drugs. Organic light-emitting diodes (OLEDs) have rapidly grown as one of the leading technologies for full-color display panels and eco-friendly lighting sources.

Intermolecular Photocatalytic Chemo-, Stereo- and Regioselective Thiol-Yne-Ene Coupling Reaction.

The first example of an intermolecular thiol-yne-ene coupling reaction is reported for the one-pot construction of C-S and C-C bonds. Thiol-yne-ene coupling opens a new dimension in building molecular complexity to access densely functionalized products. The employment of Eosin Y/DBU/MeOH photocatalytic system suppresses hydrogen atom transfer (HAT) and associative reductant upconversion (via C-S three-electron σ-bond formation).

Multicomponent Synthesis of 2-(2,4-Diamino-3-cyano-5-chromeno[2,3-]pyridin-5-yl)malonic Acids in DMSO.

Dimethyl sulfoxide is a widely used solvent in organic synthesis and in the pharmaceutical industry because of its low cost, stability, and low toxicity. Multicomponent reactions are an advanced approach that has become an efficient, economical, and eco-friendly substitute for the conventional sequential multi-step synthesis of various biologically active compounds. This approach was adopted for the synthesis of previously unknown 2-(2,4-diamino-3-cyano-5-chromeno[2,3-]pyridin-5-yl)malonic acids via transformation of salicylaldehydes, malononitrile dimer, and malonic acid.

Photoinduced assembly of the 3,4,4a,7a-tetrahydro-1-cyclopenta[]pyridine-2,7-dione core on the basis of allomaltol derivatives.

A novel photochemical method for the construction of previously unknown substituted 4a,7a-dihydroxy-5-methyl-3,4,4a,7a-tetrahydro-1-cyclopenta[]pyridine-2,7-diones based on readily available allomaltol derivatives containing an amide group was established. The proposed approach includes the photoinduced contraction of an allomaltol ring and the subsequent intramolecular cyclization of an unstable α-hydroxy-1,2-diketone intermediate. For the first time we have shown the use of a side chain amide function as a trapping element for the final cyclization of photogenerated α-hydroxy-1,2-diketones.

Unusual Effect of Impurities on the Spectral Characterization of 1,2,3-Triazoles Synthesized by the Cu-Catalyzed Azide-Alkyne Click Reaction.

The analysis of products synthesized by Cu-catalyzed click reactions can be complicated due to the presence of metal impurities in isolated substances, which may "selectively" distort some signals in NMR spectra. Such a pronounced impurity effect was found in both H and C NMR spectra for a number of 1,4-substituted 1,2,3-triazoles. Recording of the full undistorted spectra is possible with additional product treatment, with more thorough purification, or by recording the spectra at low temperatures.

Catalyst-Solvent System for PASE Approach to Hydroxyquinolinone-Substituted Chromeno[2,3-]pyridines Its Quantum Chemical Study and Investigation of Reaction Mechanism.

The Pot, Atom, and Step Economy (PASE) approach is based on the Pot economy principle and unites it with the Atom and Step Economy strategies; it ensures high efficiency, simplicity and low waste formation. The PASE approach is widely used in multicomponent chemistry. This approach was adopted for the synthesis of previously unknown hydroxyquinolinone substituted chromeno[2,3-]pyridines via reaction of salicylaldehydes, malononitrile dimer and hydroxyquinolinone.

Synthesis of substituted naphtho[1,2-b]benzofuran-7(8H)-ones via photoinduced rearrangement of 4H-chromen-4-one derivatives.

A simple and efficient method was developed for the synthesis of substituted naphtho[1,2-b]benzofuran-7(8H)-ones based on the photorearrangement reaction of 4H-chromen-4-one derivatives. The studied reaction includes the photocyclization of the hexatriene system, [1,9]-H-sigmatropic rearrangement and heterocyclic ring opening. The starting terarylenes were prepared via a new three-component tandem condensation of 3-(dimethylamino)-1-(2-hydroxyaryl)prop-2-en-1-ones, arylglyoxals and cyclic 1,3-diketones.

One-pot synthesis of substituted pyrrolo[3,4-]pyridine-4,5-diones based on the reaction of -(1-(4-hydroxy-6-methyl-2-oxo-2-pyran-3-yl)-2-oxo-2-arylethyl)acetamide with amines.

The condensation of primary amines with -(1-(4-hydroxy-6-methyl-2-oxo-2-pyran-3-yl)-2-oxo-2-arylethyl)acetamides was explored. Thus, a previously unknown recyclization of the starting material was observed in acidic ethanol in the presence of an amine, which provided the corresponding dihydropyrrolone derivative as the major reaction product. Based on this transformation, a practical and convenient one-pot synthetic method for substituted pyrrolo[3,4-]pyridin-5-ones could be devised.

Pot, atom and step economic (PASE) assembly of salicylaldehydes, malononitrile dimer and 4-hydroxypyridine-2(1H)-ones into medicinally relevant 5H-chromeno[2,3-b]pyridine scaffold.

The new multicomponent reaction (MCR) has been found: one-pot selective and efficient formation of the new 5-(4-hydroxy-2-oxo-1,2-dihydropyridin-3-yl)-substituted 5H-chromeno[2,3-b]pyridines in 61-97% yields directly from simple and easily available salicylaldehydes, malononitrile dimer and 4-hydroxypyridine-2(1H)-ones in small amount of pyridine-ethanol catalyst/solvent system. This complex "domino" transformation includes Knoevenagel condensation of salicylaldehyde with malononitrile dimer, Michael addition of 4-hydroxypyridine-2(1H)-one, double Pinner-type reaction cyclization and isomerization with following protonation. This facile multicomponent process opens a new way to 5-(4-hydroxy-2-oxo-1,2-dihydropyridin-3-yl)-substituted 5H-chromeno[2,3-b]pyridine systems, which are promising compounds for the treatment for human inflammatory TNFα-mediated diseases and different biomedical applications.

Diversity Oriented Synthesis of Polycyclic Heterocycles through the Condensation of 2-Amino[1,2,4]triazolo[1,5-a]pyrimidines with 1,3-Diketones.

The acid-catalyzed condensation between 2-aminosubstituted [1,2,4]triazolo[1,5-a]pyrimidines and their analogues with various saturation of the pyrimidine ring and 1,3-diketones or 1,1,3,3-tetramethoxypropane was evaluated as a new approach for the synthesis of diversely substituted polycyclic derivatives of triazolopyrimidine. The reaction of 4,5,6,7-tetrahydro- or aromatic aminotriazolopyrimidines results in selective formation of the corresponding [1,2,4]triazolo[1,5-a:4,3-a']dipyrimidin-5-ium salts, and the condensation of substrates containing the 4,7-dihydro-[1,2,4]triazolo[1,5-a]pyrimidine fragment is accompanied by a cascade rearrangement with unusual recyclization of the dihydropyrimidine ring to yield partially hydrogenated [1,2,4]triazolo[1,5-a:4,3-a']dipyrimidin-5-ium or pyrimido[1',2':1,5][1,2,4]triazolo[3,4-b]quinazolin-5-ium salts. The proposed methodology exhibits a wide scope, providing rapid access to polycondensed derivatives of the [1,2,4]triazolo[1,5-a]pyrimidine scaffold.

[Technical characteristics and diagnostic capabilities of low-field magnetic resonance tomographs TMR-0,06-KFTI].

The construction, performance, technical characteristics, and prospects for upgrading the low-field magnetic resonance tomograph TMR-0,06-KFTI with magnetic field induction 0.06 T developed at the Kazan Institute of Engineering Physics are described. The engineering solutions and software of the tomograph are original developments of the project team.

[Application of superoxide dismutase preparation for the prophylaxis of post-traumatic broncho-pulmonary complications].

The effectiveness of endobronchial application of superoxide dismutase (SOD) for prevention of posttraumatic bronchopulmonary complications was analyzed in 11 patients with severe combined traumas and dominating injuries of the chest. It was shown that severe combined traumas sharply initiate processes of free radical oxidation in tissues, intensify prooxidative activity, deplete total antioxidative activity and its important link--plasma and erythrocyte SOD. Endobronchial instillation of SOD after a severe combined trauma results in increased intracellular activity of catalase, total antioxidative activity, SOD, decreased production of lipid peroxides in homogenate of the pellet of bronchoalveolar lavage (BAL), reduced number of neutrophiles and higher number of lymphocytes in BAL pellet.

[Role of fiber bronchoscopy in diagnosis and treatment of severe mechanical trauma].

The article elucidates specific features of bronchopulmonary pathology diagnosed by bronchofibroscopy in 218 patients with severe mechanical traumas. The indications to primary and repeated bronchofibroscopies are formulated. The significance of emergency and urgent bronchofibroscopy for early diagnosis of different bronchopulmonary consequencies of the trauma is shown.

[Rendering surgical care to wounded with neck wounds in an armed conflict].

The results of rendering of the medical care (the first aid, qualified and specialized) obtained in 172 servicemen with neck injuries who stayed in Republic of Chechnya during the period from 09.08.1999 to 28.

[Surgical tactics in spontaneous pneumothorax].

219 cases of nonspecific spontaneous pneumothorax have been analysed. The bullous lung disease was the reason of pneumothorax in 55% of cases. Diagnostic and curative thoracoscopy is an important element of diagnosis.

[A rare case of tracheobronchomegaly].

The reported case confirms that tracheobronchomegaly may have a symptomless course. Exacerbation of process may be interpreted as "pneumonia". Only in the long course of the disease without positive clinico-roentgenological dynamics the correct diagnosis is established.

[Diagnosis and treatment of pulmonary echinococcosis in young patients].

Of the 55 young patients with echinococcosis of the lungs and pleura, in half the disease was revealed at prophylactic roentgenofluorography, in 11.5%--at examination for other disease, in 38.1%--when taking medical advice.