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  1. No Access

    Article

    Synthesis of substituted γ-pyrones

    Substituted γ-pyrones were synthesized by the acylation of phenylacetaldehyde and its enol acetate with acetic and propionic anhydrides in the presence of 70% HClO4. The mechanism of the reaction is examined, and...

    E. V. Kuznetsov, A. I. Pyshchev, G. N. Dorofeenko in Chemistry of Heterocyclic Compounds (1972)

  2. No Access

    Article

    Synthesis of natural isoflavones and their structural analogs

    A number of natural isoflavones and their structural analogs have been synthesized by improved ethyl orthoformate and dimethylformamide methods. It has been possible to use the dimethylformamide method for the...

    G. N. Dorofeenko, A. L. Shinkarenko, A. L. Kazakov… in Chemistry of Natural Compounds (1974)

  3. No Access

    Article

    Synthesis of isoflavones that have hypocholesterinemic activity

    G. N. Dorofeenko, A. L. Shinkarenko… in Chemistry of Heterocyclic Compounds (1974)

  4. No Access

    Article

    Synthesis of pyrylium salts by condensation of Β-chlorocinnamaldehydes with carbonyl compounds

    A method is proposed for the synthesis of unsymmetrical unsubstituted pyrylium salts by condensation of Β-chlorocinnamaldehydes with methyl and methylene ketones and Β-dicarbonyl compounds in the presence of HClO

    G. N. Dorofeenko, A. I. Pyshchev in Chemistry of Heterocyclic Compounds (1974)

  5. No Access

    Article

    Β-Chloro-Β-ferrocenylacrylaldehyde and its application in the synthesis of pyrylium and pyridine derivatives of ferrocene

    Β-Chloro-Β-ferrocenylacrylaldehyde, to which an s-cis configuration was assigned on the basis of the PMR spectral data, was synthesized from acetylferrocene by the Vilsmeier-Haack reaction. 2, 3, 6-Trisubstitu...

    G. N. Dorofeenko, V. V. Krasnikov, A. I. Pyshchev in Chemistry of Heterocyclic Compounds (1977)

  6. No Access

    Article

    Synthesis of γ-pyrones, flavones, and isocoumarins by destructive oxidation of pyranylidenes and their benzo analogs

    Preparative methods for the synthesis of isocoumarins, γ-pyrones, and flavones by destructive oxidation of methylenepyrans with potassium permanganate in acetone were developed.

    E. V. Kuznetsov, D. V. Pruchkin, A. I. Pyshchev… in Chemistry of Heterocyclic Compounds (1978)

  7. No Access

    Article

    Photomonocyclization of 1,2,6-triarylpyridinium cations

    It was found by UV spectroscopy and x-ray diffraction analysis that the photocyclization of 1-(3'-halophenyl)-2,4,6-triphenylpyridiniurn cations leads to stable 1,3-diphenyl-11-chloro(bromo)-azoniatriphenylene...

    Ya. R. Tymyanskii, S. M. Aldoshin… in Bulletin of the Academy of Sciences of the… (1982)

  8. No Access

    Article

    Reactions of heterocyclic cations with nitrogen-containing nucleophiles. 11. Reaction of 2,6-diphenylpyrylium perchlorate with primary amines, hydrazine, and hydroxylamine

    The reaction of 2,6-diphenylpyrylium perchlorate with methylamine and various anilines in acetic acid leads to pyridinium salts; 3,4-bispyridinium perchlorates were obtained in dimethylformamide. The reaction ...

    É. A. Zvezdina, A. N. Popova, A. I. Pyshchev… in Chemistry of Heterocyclic Compounds (1982)

  9. No Access

    Article

    Photocyclization of 1,2-diaryl- and photobicyclization of 1,2,6-triarylpyridinium cations

    New 1,2-diaryl- and 1,2,6-triarylpyridinium salts, containing various five- and six-membered heteroaromatic substituents in the 1, 2, and 6-positions of the pyridinium ring, were synthesized. New tetra- and he...

    A. R. Katritzky, B. Agha, G. Z. de Ville, E. Lunt… in Chemistry of Heterocyclic Compounds (1984)

  10. No Access

    Article

    Formation of cyanines from pyrylium salts and aliphatic acid anhydrides

    A. I. Pyshchev, L. I. Butenko, É. T. Oganesyan… in Chemistry of Heterocyclic Compounds (1989)

  11. No Access

    Article

    Dual reacting of monocyclic α-carboxypyrylium salts in reaction with secondary amines

    N. V. Kholodova, V. G. Brovchenko, A. I. Pyshchev… in Chemistry of Heterocyclic Compounds (1989)

  12. No Access

    Article

    Synthesis of flavones with hypolipidemic activity

    É. T. Oganesyan, Yu. K. Vasilenko, M. M. Khachatryan… in Pharmaceutical Chemistry Journal (1989)

  13. No Access

    Article

    Unusual recyclization of 5-methyl-2, 4-diphenyl-6-(2-N, N-dimethylaminovinyl)-3-azapyrilium perchlorate

    I. I. Nechayuk, N. V. Shibaeva, S. V. Borodaev… in Chemistry of Heterocyclic Compounds (1990)

  14. No Access

    Article

    Acid-catalyzed acylation of 4-alkyl-3-azapyrylium salts and the synthesis of 4-acylaminopyrylium salts

    4-Alkyl-3-azapyrylium salts undergo acylation at the alkyl group under acid-catalyzed conditions to give 4-acylmethyl-3-azapyrylium derivatives, which upon heating in proton-donating solvents recyclize to give...

    N. V. Shibaeva, S. V. Borodaev, I. A. Yudilevich… in Chemistry of Heterocyclic Compounds (1991)

  15. No Access

    Article

    Synthesis of 4H-1,3-oxazinium salts from an N-ethylnitrilium salt and carbonyl compounds

    S. V. Borodaev, O. V. Zubkova, N. V. Shibaeva… in Chemistry of Heterocyclic Compounds (1991)

  16. No Access

    Article

    Condensation of 6-methyl-3-azapyrylium salts to pyrido[1,2-c]pyrimidinium derivatives

    Under the influence of DMF/Ac2O 2,4-diphenyl-6-methyl-3-azapyrylium perchlorates undergo condensation to give pyrido[1,2-c]pyrimidinium perchlorates. The structure of one of the perchlorates was proved by x-ray d...

    N. V. Shibaeva, I. I. Nechayuk, S. V. Borodaev… in Chemistry of Heterocyclic Compounds (1991)

  17. No Access

    Article

    Synthesis of the alkaloid dioxyline and other 6,7-dimethoxyisoquinolines in a modified ritter reaction

    It has been found that aceto- and benzonitriles and 3,4-dimethoxyphenylacetone in the presence of acetylperchlorate or upon heating in polyphosphoric acid or polyphosphoric ester form the corresponding isoquin...

    V. G. Brovchenko, N. V. Shibaeva, A. I. Pyshchev… in Chemistry of Heterocyclic Compounds (1992)

  18. No Access

    Article

    Electrochemical interconversion of 1-(p-tolyl)-6-methyl-2,4-diphenylpyrimidinium perchlorate and 1-(p-tolyl)-6-methylene-2,4-diphenylpyrimidine

    It is shown that reduction of the 6-methyl-1-(p-tolyl)-2,4-diphenylpyrimidinium cation proceeds in two one-electron stages. In the first stage, an unstable radical is formed, and in the second stage, an unstab...

    A. A. Bumber, O. D. Lalakulich, N. V. Shibaeva… in Chemistry of Heterocyclic Compounds (1999)

  19. No Access

    Article

    Nature of weak inter-and intramolecular interactions in crystals 8. Influence of intermolecular contacts on the strength of intramolecular O-H...N bonds in crystals of 3-(2-hydroxyphenyl)-1,2,4-triazoles

    The nature and energy of the intramolecular H-bond in 3-(2-hydroxyphenyl)-1,2,4-triazoles was studied by X-ray diffraction and quantum chemical methods. In this system, the conjugation does not additionally co...

    D. G. Golovanov, A. O. Tokareva, A. I. Uraev, Yu. I. Ryabukhin… in Russian Chemical Bulletin (2006)