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A regioselective method for the synthesis of substituted (4R*,5S*,6R*)-2-thioxohexahydro-pyrimidine-5-carbohydrazides from the corresponding diastereomers of hexahydro-2H-chromeno[4,3-d]pyrimidines was developed. In acidic medium, the obtained hydrazides are prone to retro reaction to give hexahydro-2H-chromeno[4,3-d]pyrimidines.

Abstract A two-stage method for the preparation of 2-(3-carboxymethylindazol-1-yl)anilines using the N-arylation reaction of 3-carboxymethylindazoles with o-nitrohaloarenes and subsequent reduction of nitro-containing intermediates with tin(II) chloride was developed. The experimental results showed that the use of the synthesized compounds as fluorophores in the visible region of the spectrum is promising.

New pyrazolo[1,5-a]quinoxalin-4-ones were obtained by reductive cyclization from the corresponding 1-(2-nitroaryl)pyrazole-5-carboxylates. Alternatively, pyrazolo[1,5-a]quinoxalines were prepared from N-hydroxypyrazolo[1,5-a]quinoxalines.

A facile synthesis of para-quinones derived from fused benzimidazoles with a bridgehead nitrogen atom was developed. The heterocyclic quinone core formed as a result of reductive cyclization of ortho-nitroarenes containing alicyclic and aromatic azaheterocycles. Functionalization of 1,2,3,4-tetrahydro- and pyrido[1,2-a]benzimidazoles via SEAr, condensation, and reduction reactions allowed synthesis of amino derivatives which were oxidized with KNO3 in H2SO4 to obtain novel heterocyclic quinones.

A general and efficient method has been developed for the synthesis of NH-indoles bearing electron-accepting substituents via the modification of corresponding N-hydroxyindoles.

A synthetic route to novel 3-bromo-substituted 1-hydroxypyrrolo[3,4-f]indole-5,7-diones via the reaction of 1-hydroxypyrrolo[3,4-f]indole-5,7-diones with N-bromosuccinimide was developed.

A three-step procedure has been developed for the synthesis of 2-oxo-2,3-dihydro-1H-imidazo-[1,2-a]indole-6,7-dicarbonitriles from substituted 2-amino-1-hydroxy-1H-indole-5,6-dicarbonitriles.

Synthetic methods for preparation of novel 3-acyl-substituted 1-hydroxyindole-5,6-dicarboxylic acids and 1-hydroxy-pyrrolo[3,4-f]indole-5,7-diones from 4-(2-substituted-2-oxoethyl)-5-nitrophthalonitriles via successive Vilsmeier-Haack and reductive cyclization reactions were developed.

Chlorination of 1-hydroxyindole-5,6-dicarbonitriles and 1-hydroxypyrrolo[3,4-f]indole-5,7(1H,6H)-diones with N-chlorosuccinimide afforded previously unknown 3,3-dichloro-3Hindole 1-oxides instead of the expected 3-chloro-1-hydroxyindoles. The latter, however, were prepared in good yields by treatment of the above 3,3-dichloro-3H-indole 1-oxides with piperidine in ethanol. Reduction of 3,3-dichloro-5,6-dicyano-3H-indole 1-oxides with Zn in AcOH yielded the corresponding 3-chloroindole-5,6-dicarbonitriles.

Synthetic routes to novel substituted benzofuran-5,6-dicarboxylic acids and furo[2,3-f]isoindole-5,7-diones via acid hydrolysis of the corresponding benzofuran-5,6-dicarbonitriles were developed.

New nitro and sulfonamide derivatives of [1,3,4]thiadiazolo[3,2-a]quinazolin-5-one have been synthesized by cyclocondensation of 1,3,4-thiadiazol-2-amines with 2-halobenzoyl chlorides containing electron-withdrawing substituents in positions 3, 4, and 5. An improved procedure has been proposed for the preparation of intermediate 2-fluoro-N-(5-methyl-1,3,4-thiadiazol-2-yl)benzamides containing a sulfamoyl group in the 5-position via selective acylation of 5-methyl-1,3,4-thiadiazol-2-amine with 5-chlorosulfonyl-2-fluorobenzoyl chloride, followed by sulfonylation of amines.

Preparation procedure was developed for 3-formylindole-5,6-dicarbonitriles underlain by the treatment of 1-acetoxyindole-5,6-dicarbonitriles with Vilsmeier-Haack reagent; a special feature of this reaction consisted in a replacement of the OAc group for hydrogen. A probable mechanism was assumed of the formation of 3-formylindole-5,6-dicarbonitriles.

Methods of synthesis of chalcones from 2-substituted 3-acetyl- and 3-formyl-1-hydroxyindole-5,6-dicarbonitriles under acidic conditions have been developed.

A general approach to the synthesis of new 3-acetyl-substituted pyrrolo[3,4-f]indole-5,7-diones, 3-[3-(dimethylamino)acryloyl]-1-methoxypyrrolo[3,4-f]indole-5,7-diones and similar indole-5,6-dicarbonitriles has been developed. Dimethylaminoacryloyl derivatives synthesized on their basis regioselectively reacted with hydrazine hydrochlorides and hydroxylamine with the formation of the corresponding 5-substituted azoles.

General methods to access new 3-formyl-substituted 1-methoxypyrrolo[3,4-f]indole-5,7-diones were developed. The synthesized 3-formylindoles react with heterocyclic aceto-phenones under acid-catalyzed conditions to give different chalcones.

Principal synthetic approaches to the synthesis of indole-5,6- and carbazole-2,3-dicarboxylic acid functional derivatives are considered. The first of them consists in the construction of the indole ring from simpler aromatic compounds containing carboxy groups, cyano groups, or an imide fragment with subsequent reductive cyclization of the compounds formed. The second approach is based on the modification of a pyrrole or an indole fragment by the introduction of different functional groups with subsequent intramolecular cyclization to the corresponding heterocycles.

General methods were developed of the synthesis of N-substituted 1-hydroxypyrrolo[3,4-f]indole-5,7-diones using as initial compounds substituted 6-nitroisoindole-1,3-diones and 5-nitro-4-phenacylphtalic acids.

Procedures have been developed for the synthesis of 2-formylbenzofuran-5,6-dicarbonitriles, 5,6-dicyanobenzofuran-2-carboxylic acids, and formyldibenzo[b,d]furan-2,3-dicarbonitriles by modification of 2-(2-aminovinyl)benzofuran-5,6-dicarbonitriles with sodium periodate or Vilsmeier reagent.

A number of new functional derivatives of pyrido[2,1-c][1,2,4]benzothiadiazine 5,5-dioxide was obtained based on the reactions of 2-halobenzenesulfonyl chlorides with 2-aminopyridine derivatives. A quantitative criterion for the evaluation of a possibility for the reaction to proceed under noncatalytic conditions depending on the type of halogen and substituents in the starting compounds was suggested.

Methods were developed of indirect introduction of sulfonamide group in the structures of pyrido-[2,1-b]quinazolin-11-one and pyrido[1,2-a]quinazolin-6-one underlain by cyclocondensation of 2-halo-5-(Rsulfamoyl) benzoyl chlorides with derivatives of 2-aminopyridine. The fact of thermal rearrangement of 8-(morpholin-4-ylsulfonyl)pyrido[1,2-a]quinazolin-6-one into isomeric 2-(morpholine-4-ylsulfonyl)pyrido[2,1-b]-quinazolin-11-one was experimentally registered.

A general procedure has been proposed for the synthesis of thiazolo[3,2-a]quinazolin-5-one derivatives containing a sulfonamide group on C7 via intramolecular nucleophilic substitution of halogen in 2-halo-5-sulfamoyl-N-(1,3-thiazol-2-yl)benzamides. The effects of the degree of activation of the initial compound and halogen nature on the yield of the target products have been analyzed.

Methods of the synthesis of new dibenz[b,f]oxepine-2,3-dicarbonitriles and dibenz[b,f]oxazepine-10,11-dicarbonitriles was developed employing as substrates 4-methyl-5-nitrophthalonitrile and 4-bromo-5-nitrophthalonitrile.

Some regularities are discussed of the reaction between 3-substituted benzofuran-5,6-dicarbonitriles with hydrazines leading to the formation of new 4-hydroxy-5-[aryl(alkyl)-1H-pyrazol-4-yl]-benzene-1,2-dicarbonitriles.

The reaction of aromatic nucleophilic substitution in 4-methyl-5-nitrophthalonitrile with reagents different structures was used for the synthesis of new substituted 4-azidophthalonitriles. The interaction of the obtained 4-azidophthalonitriles with acetylacetone leads to the formation of substituted (1,2,3-triazol-1-yl)-5-styrylphthalonitriles; the refluxing of 4-azidophthalonitriles in ethyleneglycol results in formation of 2-aryl-1H-indole-5,6-dicarbonitriles. The obtained nitrogen-containing heterocyclic ortho-dicarbonitriles can be used for preparation of macroheterocycles. The structure of all products was established by the data of IR, NMR spectroscopy (including two-dimensional correlation NOESYspectroscopy) and mass-spectrometry.

Reactions of 2-(4-methylphenyl)[1,3]triazolo[3,2-b][1,2,4]thiazol-6(5H)-one and 5-benzylidene-2-(4-methylphenyl)[1,3]thiazolo[3,2-b][1,2,4]triazol-6(5H)-one with amines and hydrazines of diverse structures were studied. The structure of the reaction products was established.

4-(1-Benzotriazolyl)-5-[1(2)-naphthyloxy]phthalodinitriles were obtained by nucleophilic substitution of bromine and nitro group in 4-bromo-5-nitrophthalodinitrile. These compounds were used for the synthesis of the corresponding octa-substituted phthalocyanines. Spectral data of the compounds obtained were examined.

We have developed a novel regioselective method for synthesis of substituted spiro([1]benzopyran-2,4'-(1'H)pyrimidine)-2'-(3'H)thiones and spiro([1]benzopyran-2,4'-(1'H)pyrimidin)-2'-(3'H)ones having one or two hydroxyl groups on the benzene ring.

A large number of novel 3-(heterocyclylsulfonyl)propanoic acids and their amide derivatives were prepared in good yields and excellent purity starting from the corresponding heterocyclic compounds. At first, chlorosulfonates were generated by reaction of initial heterocycles with various sulfonating and chlorinating agents followed by their conversion into sodium sulfinates. Treatment of sulfinates with acrylic acid smoothly afforded a series of sulfonylpropionates, which were used as convenient reagents for the preparation of a large number of the corresponding carboxamide derivatives.

We have developed a novel regioselective method for synthesis of substituted spiro([1]benzopyran-2,4'-(1'H)pyrimidine)-2'-(3'H)thiones and spiro([1]benzopyran-2,4'-(1'H)pyrimidin)-2'-(3'H)ones having one or two hydroxyl groups on the benzene ring.

The dependence of the temperature of a system of nonequilibrium electrons on the injection current is derived for cw and pulsed injection semiconductor lasers using a published model of quantum transitions in such lasers. It is shown that pumping of a laser with current pulses of sufficiently short duration (tens of nanoseconds) results in a significant difference between the electron and crystal lattice temperatures, which increases on increase in the pulse amplitude. This increase shifts the emission line, governed by the spectral position of the optical gain maximum, toward shorter wavelengths, in contrast to the usual shift toward longer wavelengths observed in the case of pumping with a constant current or with pulses of sufficiently large duration (in excess of 100 ns). These theoretical results are supported by data obtained in an experiment on a gallium arsenide homojunction laser.

Real-time sonography was carried out in 273 patients with metastatic lesions in the liver. Sonographic patterns of hepatic metastases were identified. Relationships between sonographic semiotics and patterns of primary tumor are discussed.

The only method of preoperative visualization of spread of the process in the soft tissues (phlegmons, abscesses etc.) is the ultrasonic examination which was used in 32 patients. The diagnostic significance of echography in chronic osteomyelitis was 50%, suppuration in the soft tissues was 92.3%.