Preparative and theoretical study on chain length-dependence and substrate selectivity in the cycloalkylation of condensed [1,2,4]triazolo[4,3-b]pyridazine-6(5H)-one-3(2H)-thiones

A. Csámpai, Mónika Simó, Zoltán Szlávik, András Kotschy, G. Magyarfalvi, György Túrós

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Cyclization of condensed [1,2,4]triazolo[4,3-b]pyridazine-3(2H)-6(5H)-ones with α,ω-dibromoalkanes afforded a series of novel ring systems including zwitterions and isomeric tetracyclic lactams. The product distribution is controlled by the chain-length of the reagent, the polarity of the solvent and the structure of ring A in the substrate. The observed substrate selectivity was interpreted on the basis of amide-I IR frequencies and by the results of ab initio B3LYP DFT calculations carried out at 6-31G and 6-31G(d) basis sets using IPCM solvation model. The cycloalkylation with 1,4-dibromobutane gave also macrocyles as detectable by-products which underwent ring contraction yielding lactams on attempted chromatographic separation.

Original languageEnglish
Pages (from-to)8963-8972
Number of pages10
JournalTetrahedron
Volume58
Issue number44
DOIs
Publication statusPublished - Oct 28 2002

Fingerprint

Thiones
Lactams
Chain length
Theoretical Models
Cyclization
Solvation
Substrates
Discrete Fourier transforms
Amides
Byproducts
pyridazine
IPCM
1,4-dibromobutane

Keywords

  • Cyclisation
  • Lactames
  • Theoretical studies
  • Zwitterions

ASJC Scopus subject areas

  • Biochemistry
  • Organic Chemistry
  • Drug Discovery

Cite this

Preparative and theoretical study on chain length-dependence and substrate selectivity in the cycloalkylation of condensed [1,2,4]triazolo[4,3-b]pyridazine-6(5H)-one-3(2H)-thiones. / Csámpai, A.; Simó, Mónika; Szlávik, Zoltán; Kotschy, András; Magyarfalvi, G.; Túrós, György.

In: Tetrahedron, Vol. 58, No. 44, 28.10.2002, p. 8963-8972.

Research output: Contribution to journalArticle

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AU - Szlávik, Zoltán

AU - Kotschy, András

AU - Magyarfalvi, G.

AU - Túrós, György

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