Synthesis of heterocyclic systems with a carbohydrate fragment

Levoglucosenone reacts with α-aminoazoles to yield azolo[1,5-a]pyrimidine systems fused with a carbohydrate fragment. The reaction oocurs much more smoothly than in the case of other α,β-unsaturated ketones. The reactions of levoglucosenone with β-dicarbonyl compounds (dimedone, barbituric acid) in the presence of a base results in the pyran ring closure, which has never been observed earlier in reactions of β-dicarbonyl compounds with α,β-unsaturated ketones under the conditions of basic catalysis. The structures of products were established by IR and NMR spectroscopy. For Part 3, see Ref. 1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 3, pp. 553–558, March, 1997.     

Synthesis of 5-azaadenine derivatives from N-(1,2,4-triazol-5-yl)amidines

A method is proposed for the synthesis of N-substituted 5-azaadenines. The condensation of N-(1,2,4-triazol-5-yl)amidines with trichloroacetonitrile gives trichloromethyl derivatives of 1,2,4-triazolo[1,5-a]-1,3,5-triazines, which are converted by the action of primary or secondary amines into N-alkylamino- or N,N-dialkylamino-1,2,4-triazolo-[1,5-a]-1,3,5-triazines (5-azaadenines).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 241–243, January, 1991.     

Electrode transformations of carbanions and heteroanions

Conclusions The electrolytic oxidation of the 3-nitro-1,2,4-triazole anion is realized through an intermediate radical, which splits out an H atom on reaction with the medium and reacts with benzene to give N-substituted phenyl-3-nitro-1,2,4-triazoles.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1643–1646, July, 1988.     

Gem-dinitro compounds in organic synthesis. 4. Use of the condensation product of glyoxal and dinitromethane in the synthesis of nitro-1,2,3-triazoles

The condensation of dinitromethane with glyoxal has been investigated and it has been demonstrated that 1,1,4,4-tetranitro-2,3-butandiol, -hydroxy-,-dinitropropionic acid or their mixture may be formed. Interaction of 1,1,4,4-tetranitro-2,3-butandiol or 1,4-dibromo-1,1,4,4-tetranitro-2,3-butanediol diacetates with sodium azide leads to bis(5-nitro-1,2,3-triazol-4-yl) via intermediate 1,1,4,4-tetranitro-1,3-butadiene.For communication 3, see [1].N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 9, pp. 2123–2131, September, 1992.     

Synthesis of α-functional nitro compounds by the nitration of activated carbonyl compounds in a two-phase system

2-Nitro-1,3-dicarbonyl and -nitromonocarbonyl compounds were synthesized in the yields varying from moderate (30 %) to nearly quantitative by the nitration of -dicarbonyl compounds in a two-phase system: sulfuric/nitric acid mixture-chloroform at - 10÷10 °C. The use of phase transfer conditions made it possible to avoid the formation of furoxans as by-products and to simplify the isolation of products. This method is quite common for preparing various -functional nitro compounds including those containing a CF₃-group. Key words: nitration, -functional nitro compounds.Translated fromIzvestiya Akademn Nauk. Seriya Khimicheskaya, No. 1, pp. 76–79, January, 1994.     

Research in the field of furopyridines. 2. Synthesis and steric structure of 6-methyl-1-hetarylidene-3,4-dioxo[3,4-c]pyridines

By condensation of 6-methyl-3,4-dioxo-1H-furo[3,4-c]pyridine with heteroaromatic aldehydes, furfurylidene- and thenylidenefuropyridinediones have been obtained. By means of ¹H NMR spectrometry using the nuclear Overhauser effect, it has been established that these compounds have the cis-s-cis and cis-s-trans conformations, respectively.For Communication 1, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 29, No. 5, pp. 633–638, May, 1993.     

15N NMR spectral parameters of compounds of the N-methylpyrazole series

The¹⁵N NMR chemical shifts and¹⁵N-¹H SSCCs are presented for substituted N-methylpyrazoles with substituents such as CH₃, NO₂, Br, Cl, NH₂, O=CNH₂, O=CPh, and COOH at the carbon atoms. The¹⁵N chemical shifts of the cyclic atoms of nitrogen and the nitro groups are discussed as well as the geminal and vicinal SSCCs of the ring nitrogen atoms with the hydrogen atoms of the CH and CH₃ fragments.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117334 Moscow. D. I. Mendeleev Chemico-Technological Institute, Moscow, Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No. 11, pp. 2554–2561, November, 1992.     

N-Arylation of azoles with low basicity by 1,4-dimethoxybenzene during undivided electrolysis

The reactions of 1,4-dimethoxybenzene with 4-nitropyrazole, 3,4-dinitro-5-methylpyrazole, 1,2,4-triazole, 3-nitro-1,2,4-triazole, and tetrazole were studied during undivided amperostatic electrolysis on a Pt electrode in MeCN, CH₂Cl₂, and MeOH. The main reaction products were 2-azolyl-1,4-dimethoxybenzenes and (or) 1,4-diazolyl-1,4-dimethoxycyclohexa-2,5-dienes. In all cases except 1,2,4-triazole, N-arylation occurs only in the presence of the Alk₄N⁺ salts of azoles or 2,4,6-trimethylpyridine as a base. The mechanism of the reactions is discussed.     

Adamantylation of Indazole and Its C-Nitro Derivatives

Adamantylation of indazole and its C-nitro derivatives with 1-hydroxyadamantane in mineral acids yields exclusively the corresponding 1-(1-adamantyl)indazoles via attack by 1-adamantyl cation on the protonated substrate. The oxidative alkylation with 1-iodoadamantane leads to formation of 1- and 2-(1-adamantyl)indazoles, the 2-isomer prevailing.     

Synthesis of heterocycles on the basis of products of addition of polyhaloalkanes to unsaturated systems.

Oximes of 3,3-dichloropropenal and 4,4,4-trifluoro-3-chloro-1-butenal were obtained on the basis of products of free-radical addition of CCl₄ and CF₃CCl₃ to vinyl butyl ether. Generation of the corresponding nitrile oxides from these oximes and reaction of the nitrile oxides in situ with vinyl butyl ether, phenylacetylene, and propargyl alcohol via the scheme of 1,3-dipolar cycloaddition are proposed as a method for the synthesis of isoxazoles containing ,-dichlorovinyl and -trifluoromethyl--chlorovinyl substituents in the 3 position.See [1] for Communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1250–1255, September, 1990.