Unexpected results in the heterocyclization of 5-acetylenylpyrazole-4- carboxylic acid hydrazides under the influence of CuCl: Formation of a diazepinone and dehydrodimerization into the corresponding bis(pyrazolo[4,3-d] [1,2]diazepinone)

Sergei F. Vasilevsky, Elena V. Mshvidobadze, Victor I. Mamatyuk, Galina V. Romanenko, Jose Elguero

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16 Citations (Scopus)


The simple reaction of cyclization of hydrazides of vic-acetylenylbenzoic and acetylenylpyrazole carboxylic acid can lead to four different compounds: five-membered N-aminolactams, six-membered N-aminolactams, six-membered diazinones and diazepinones, but only the first three have been described. In this paper we report the unexpected formation of a bis(pyrazolo[4,3-d][1,2] diazepinone, the structure of which has been established by X-ray crystallography.

Original languageEnglish
Pages (from-to)4457-4459
Number of pages3
JournalTetrahedron Letters
Issue number26
Publication statusPublished - 27 Jun 2005
Externally publishedYes



  • Cross-coupling
  • Hetarylacetylenes
  • Heterocyclization
  • Pyrazolopyridines

ASJC Scopus subject areas

  • Biochemistry
  • Drug Discovery
  • Organic Chemistry

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