Chemistry of Heterocyclic Compounds

, Volume 41, Issue 7, pp 845–849 | Cite as

Isomerization of 2-Phenacyl-1H-benzimidazole Arylhydrazones to 1-Aryl-5-(o-aminoanilino)-3-phenylpyrazoles by Trifluoroacetylation and Hydrazinolysis

  • I. B. Dzvinchuk
  • M. O. Lozinskii


A convenient preparative two-stage method was developed for the isomerization of 2-phenacyl-1H-benzimidazole arylhydrazones to previously unknown 5-(o-aminoanilino)-1-aryl-3-phenylpyrazoles. The transformation scheme includes recyclization during acylation with trifluoroacetic anhydride leading to the formation of 1-aryl-3-phenyl-5-(o-trifluoroacetylaminoanilino)pyrazoles, which then undergo hydrazinolysis.


benzimidazoles hydrazones pyrazoles trifluoroacetic anhydride hydrazinolysis recyclization 


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  1. 1.
    O. P. Shvaika and V. N. Artemov, Zh. Obshch. Khim., 41, 1788 (1972).Google Scholar
  2. 2.
    H. C. Van der Plas, Ring Transformation of Heterocycles, Wiley, New York, etc. (1972), Vol. 1, 2.Google Scholar
  3. 3.
    N. Vivona, S. Buscemi, V. Frenna, and G. Gusmano, in: A. R. Katritzky (editor), Advances in Heterocyclic Chemistry, Academic Press, New York (1993), Vol. 56, p. 49.Google Scholar
  4. 4.
    E. V. Babaev and N. S. Zefirov, Khim. Geterotsikl. Soedin., 1564 (1996).Google Scholar
  5. 5.
    G. Hajos, Z. Riedl, and G. Kollenz, Eur. J. Org. Chem., 18, 3405 2001).CrossRefGoogle Scholar
  6. 6.
    I. B. Dzvinchuk and M. O. Lozinskii, Khim. Geterotsikl. Soedin., 206 (2005).Google Scholar
  7. 7.
    I. B. Dzvinchuk, A. V. Vypirailenko, and M. O. Lozinskii, Zh. Org. Khim., 32, 1759 (1996).Google Scholar
  8. 8.
    I. B. Dzvinchuk, A. V. Vypirailenko, and M. O. Lozinskii, Zh. Org. Khim., 33, 116 (1997).Google Scholar

Copyright information

© Springer Science+Business Media, Inc. 2005

Authors and Affiliations

  • I. B. Dzvinchuk
    • 1
  • M. O. Lozinskii
    • 1
  1. 1.Institute of Organic ChemistryNational Academy of Sciences of UkraineKievUkraine

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