A new synthesis of the linearly fused [1,2,4]triazolo[1,5-b]isoquinoline ring. Observation of an unexpected Dimroth rearrangement

László Filák, Z. Riedl, O. Egyed, M. Czugler, Cuong N. Hoang, Joachim G. Schantl, G. Hajós

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

A new and general synthesis of the linearly fused [1,2,4]triazolo[1,5-b]isoquinoline ring system starting from 2,3-diaminoisoquinolinium salts has been elaborated. Starting compounds bearing an alkyl group in position 4 easily reacted with aldehydes to yield the cyclized products. In the case of a lack of electron donating group in position 4 (e.g., unsubstituted or 4-cyano substituted diamino derivatives) a Dimroth rearrangement took place under the same reaction conditions to yield 3-isoquinolylhydrazones. The mechanism of this unexpected transformation has been verified by isotope labelling experiments. Clarification of the reaction mechanism allowed finding proper reaction conditions to eliminate the rearrangement route, and thus, to perfect successful ring closure to the fused triazoles.

Original languageEnglish
Pages (from-to)1101-1113
Number of pages13
JournalTetrahedron
Volume64
Issue number6
DOIs
Publication statusPublished - Feb 4 2008

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Bearings (structural)
Isotope Labeling
Triazoles
Aldehydes
Isotopes
Labeling
Salts
Observation
Electrons
Derivatives
Experiments
isoquinoline

Keywords

  • N labelling
  • Dimroth rearrangement
  • Hydrazone
  • Triazole

ASJC Scopus subject areas

  • Biochemistry
  • Organic Chemistry
  • Drug Discovery

Cite this

A new synthesis of the linearly fused [1,2,4]triazolo[1,5-b]isoquinoline ring. Observation of an unexpected Dimroth rearrangement. / Filák, László; Riedl, Z.; Egyed, O.; Czugler, M.; Hoang, Cuong N.; Schantl, Joachim G.; Hajós, G.

In: Tetrahedron, Vol. 64, No. 6, 04.02.2008, p. 1101-1113.

Research output: Contribution to journalArticle

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AU - Filák, László

AU - Riedl, Z.

AU - Egyed, O.

AU - Czugler, M.

AU - Hoang, Cuong N.

AU - Schantl, Joachim G.

AU - Hajós, G.

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