Fluorobenzo-1,4-thiazine oxides from bis-(vinylsulfinyl)-and bis(vinylsulfonyl)-fluorobenzenes and 2-aminoethanol

It has been established that 1, 2, 4, 5-tetrafluoro-3, 6-bis (vinylsulfinyl)- and 1, 2, 4, 5-tetrafluoro-3, 6bis(vinylsulfonyl)benzenes react with 2-aminoethanol by nucleophilic addition at the activated double bond with replacement of fluorine atoms on the benzene ring by the amino group of 2-aminoethanol to give 4, 9-bis(2 hydroxyethyl)-5,10-difluoro-1, 2, 3, 4, 6, 7, 8, 9-octahydrobenzo[1, 2-b; 5, 4-b]di-1, 4-thiazine 1,6-dioxide and 1, 1, 6, 6-tetraoxide respectively.Irkutsk Institute of Organic Chemistry, Siberian Branch of the Russian Academy of Sciences (SO RAN), Irkutsk 664033. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1195–1198, September, 1996. Original article submitted June 5, 1996.Deceased     

Reaction of 3-thiolene 1,1-dioxide with PH-acids

The nucleophilic addition of 2-phenylethylphosphine, bis(2-phenylethyl)phosphine oxide, and bis(2-phenylpropyl)phosphine oxide to 3-thiolene 1,1-dioxide catalyzed by the KOH-DMSO system leads to bis(3-thioanil) (2-phenylethyl)phosphine oxide, bis(2-phenylethyl) (3-thianil)phosphine oxide, and bis(2-phenylpropyl) (3-thioanil)phosphine oxide, respectively.Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, 664033 Irkutsk. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1195–1198, September, 1998.     

Triethoxy(3-isothiocyanatopropyl)silane

The reaction of triethoxy(3-aminopropyl)silane with carbon disulfide andortho-chloroethyl formate in absolute ethanol gave triethoxy(3-isothiocyanatopropyl)silane for the first time. The presence of SCN and (C₂H₅O)₃Si groups in this compound enabled us to use it for the preparation of adsorbents and polymer coatings with biocidal activity.Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 664033 Irkutsk. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2681–2682, November, 1992.     

Reaction of lithioalkoxyallenes with isothio-cyanates: Synthesis of pyrroles and 5,6-dihydropyridines

We have found a novel synthesis route for 2,3-disubstituted pyrroles and 5,6-dihydropyridines, starting from lithiated alkoxyallenes, and organic isothiocyanates.Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk 664033. Preparative Organic Chemistry Group, Utrecht University, The Netherlands. Translated from Khimya Geterotsiklicheskikh Soedinenii, Vol. 32, No. 7, pp. 917–918, July, 1996. Original article submitted April 17, 1996.     

Interpretation of photoelectron spectra in the AM1 semiempirical method. 3. 2-Substituted benzimidazoles

Analysis of photoelectron spectra of 2-substituted benzimidazoles showed that their orbital structure is determined by the form and energy position of the fragment orbital (-symmetry) of the substituent.For previous communication, see [1].Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk 664033. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 880–884, April, 1992.     

Reaction of 2-aminobenzimidazole with acetylene

The reaction of 2-aminobenzimidazole (1) with acetylene under pressure proceeds with the formation of vinyl monomers, corresponding to amine and imine forms, 1-vinyl-2-amino- and 1,3-divinyl-2-iminobenzimidazoles, depending on the reaction conditions. 1,3-Divinyl-2-benzimidazolone was also isolated in aqueous dioxane in addition to the monovinyl derivative of1. Cyclization of the divinyl derivative of1 with acetylene proceeds to give 9-vinyl-1,2-dimethylimidazo[1,2-a]-benzimidazole.Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 664033 Irkutsk. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 749–751, March, 1992.     

Reaction of benzothiazol-2-one with 4-hydroxy-4-methyl-2-pentynonitrile

Reaction between the title compounds gave the unexpected 3-[5,5-dimethyl-2,5-dihydrofur-4-yl-2-(3-isopropanol-2-propenonitrile)imino]benzothiazol-2-one, as a result of the addition of two cyanoacetylene molecules.Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk 664033. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 4, pp. 1003–1005, April, 1992.     

2-Iminothiopyrans from methylthiobutadiene and isothiocyanates

We have found a novel and simple approach to synthesis of 2-alkyl-3-(methylthio)-5,6-dihydro-2H-2-thiopyranimines by reactions of isothiocyanates with the carbanion of methylthiobutadiene, generatedin situ when treated with the superbasic system BuLi-t-BuOK. We have established that alkylation of the synthesized thiopyrans with methyliodide in the presence oft-BuOK leads to N-alkyl-1,2-di(methylthio)-2,4-pentadiene-1-imines.Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk 664033, Russia. Department of Preparative Organic chemistry, Utrecht University, 3584 CX Utrecht, Netherlands. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 626–629, May, 1998.     

Thermal methods for the synthesis of thiophene, selenophene, and their derivatives. (Review)

The literature data concerned with thermal reactions producing thiophene, selenophene, and their derivatives are systematized and reviewed. The mechanisms of these reactions are examined and conditions for the formation of thiophene and selenophene heterocycles are formulated.Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk 664039, Russia; e-mail: vlad@irioch.ira.ru. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 3–18, January, 2000.     

Cyanoacetylenes in reaction with benzimidazol-2-one

The reaction of 1-phenyl-2-cyanoacetylene and 4-hydroxy-4-methyl-2-pentynenitrile with benzimidazol-2-one was studied. The respective N,N-diadducts were obtained. It was shown that the addition of benzimidazol-2-one to the tertiary cyanoacetylenic alcohol catalyzed by bases is accompanied by intramolecular cyclization.Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 664033 Irkutsk. Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 6, pp. 1140–1443, June, 1992.     

13C NMR spectra of 3- and 5-substituted flavone derivatives

Summary The¹³C NMR of a number of 3- and 5-hydroxyflavones and of 3- and 5-methoxyflavones have been studied for the first time and all the signals have been assigned. A comparison of the chemical shifts of the¹³C nuclei with the acidity and basicity parameters of the compounds investigated and with the results of calculations of -charge density has been made. It has been shown that the chemical shifts of the individual signals in the¹³C NMR spectra are qualitatively connected with estimates of the reactivities of the compounds studied.Irkutsk Institute of Organic Chemistry, Siberian Branch of the Academy of Sciences of the USSR. A. A. Zhdanov Irkutsk State University. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 513–519, July–August, 1977.     

Synthesis of polyfunctionally substituted benzothiazines based on vinylthionahlobenzenes and 2-mercaptoethylamine

Regioselective nucleophilic substitution of the fluorine atoms in positions 2 and 5 of the benzene ring takes place in the reaction of 3,6-bis(vinylthio)-1,2,4,5-tetrafluoro- and 3-vinylthio-6-chloro-1,2,4,5-tetrafluorobenzenes with 2-mercaptoethylamine in isopropyl alcohol-water-dimethylformamide mixture at 40–45°C in the presence of KOH. The products of disubstitution obtained are converted into 1,4-benzothiazines on heating to 100°C in dimethylformamide in the presence of K₂CO₃ as a result of intramolecular substitution.Irkutsk Institute of Chemistry, Siberian Branch, Russian Academy of Sciences, Irkutsk 664033, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 706–709, May, 1998.     

Electron diffraction investigation of the structure of the 3,3-dimethyl-3-silathiophane molecule

Chemistry Faculty, M. V. Lomonosov Moscow State University. Irkutsk Institute of Organic Chemistry. Translated from Zhurnal Strukturnoi Khimii, Vol. 32, No. 2, pp. 148–151, March–April, 1991.     

Selective synthesis of di(propen-1-yl)sulfone and di(propen-1-yl)sulfoxide

Convenient selective methods of synthesis of the title compounds, based on oxidation of di(propen-1-yl)sulfide with 30% H₂O₂, have been developed.Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 664033 Irkutsk. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 675–679, March, 1992.     

Interaction of thermal acylacetylenes with thiosemicarbazide and 4-methyl- and 4-phenylthiosemicarbazides

By the reaction of thiosemicarbazide and 4-methyl- and 4-phenylthiosemicarbazides with terminal -acetylenic ketones, depending on the conditions, thiosemicarbazones of acylacetic aldehyde, 1,1-bis(acylvinyl)thiosemicarbazides,and5-phenylamino-2-acylmethyl-3-acylvinyl-1,3,4-thiadiazolinesareobtained. Ring-chain tautomerism of the 1,1-bis(acylvinyl)thiosemicarbazides has been investigated.Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences, 664033 Irkutsk. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1843–1849, August, 1992.     

Synthesis of substituted 2-alkyl(aryl)thio-3-cyanopyridines and 3-aminothieno[2,3-b]pyridines

The alkylation of 6-methyl-4-methoxymethyl-3-cyano-2-(1H)pyridinethione by halogen derivatives in the presence of KOH proceeds regioselectively with the formation of S-alkyl derivatives. By cathodic electrolysis of the thiols in the presence of 6-methyl-4-methoxymethyl-2-chloro-3-cyanopyridine, 2-arylthiopyridines are obtained. By Thorpe-Ziegler cyclization of 2-alkylthiopyridines having an ctive methylene group, 2-aminothieno[2,3-b]pyridines have been synthesized.Kuban State Technological University, Krasnodar, 350072. N. D. Zelinskii Institute of Organic Chemistry, Moscow 117913. Southern Branch of Association Rosvuznauka, Krasnodar, 350072. Translated from Khimiya Geterotsiklicheskikh Soedinenii, NO. 10, pp. 1432–1437, October, 1996. Original article submitted April 2, 1996; revision submitted August 20, 1996.     

Formation of 1-(2-aminophenyl)-5-ethoxy-4-methyl-3-phenylpyrazole and 4-methyl-3-phenylpyrazolo-[5,1-b]benzimidazole via an unusual enzotriazole ring opening

Successive treatment of N-[(1-ethoxy)alken-2-yl]benzotriazoles VII with butyllithium and trimethylsilyl chloride in TH-Fat — 78°C followed by refluxing in acidic acetone generated ring-opened 1-(2-aminophenyl)-5-ethoxy-4-methyl-3 phenylpyrazole VIII and 4-methyl-3 phenylpyrazolo[5, 1-b]benzimidazole IX.Published in Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 775–780, June, 1996. Original article submitted May 14, 1996.     

Ultraviolet absorption of flavonoids. V. The structure of 3- and 5-hydroxyflavones

Summary 1. The peculiarities of the properties of 3-hydroxyflavone are due to the fact that the introduction of the proton-donating hydroxy group directly into the heterocycle leads to an increase in the aromaticity of the pyrone fragment through the stabilization of a pyrylium structure.2. The causes of the decreased acidity and basicity of 5-hydroxyflavone are the formation of an intramolecular hydrogen bond of the chelate type and a disturbance of the coplanarity of the molecule. The combination of these factors explains the anomalously high position of the band of the stretching vibrations of the carbonyl group of this compound.Irkutsk Institute of Organic Chemistry, Siberian Branch of the Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 583–587, September–October, 1975.     

Quantitative1H and13C NMR spectroscopy of lignins from an aqueous ethanolic cook of aspen wood

General and comparative characteristics obtained by¹H and¹³C NMR spectroscopy of the lignins from aqueous ethanolic cooks are presented. It is shown that degradation of the lignin macromolecule takes place during the digestion of aspen wood. The mean length of the lignin side chains decreases and ether bonds are cleaved, while the degree of condensation of the substances increases.Irkutsk State University. Irkutsk Institute of Organic Chemistry, Siberian Branch, Russian Academy of Sciences. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 277–285, March–April, 1993.     

PMR spectra of natural stilbene compounds

Summary 1. The PMR spectra of 13 natural stilbenes have been studied.2. The dominating role of -electron interaction of the fragments of the stilbene molecule in the screening of the aromatic and olefinic protons has been shown. A series of increments presenting interest for determining the structure of stilbene compounds is proposed.3. It has been established that the nature and nature and number of the substituents in the aglycone part of the molecule have no influence on the screening of the anomeric proton of glycosidated stilbenes, but it does depend on the position of attachment of the carbohydrate fragment.A. A. Zhdanov Irkutsk State University. Irkutsk Institute of Organic Chemistry, Siberian Branch of the Academy of Sciences of the USSR. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 3–10, January–February, 1976.