A new cyclization to fused pyrazoles tunable for pericyclic or pseudopericyclic route: An experimental and theoretical study

László Filák, T. Rokob, Gyöngyvér Ágnes Vaskó, O. Egyed, A. Gömöry, Z. Riedl, G. Hajós

Research output: Contribution to journalArticle

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Abstract

(Chemical Equation Presented) 2-Pyrazinyl (2) and 3-pyridazinylketone arylhydrazones (6) and their benzologues undergo a ring closure reaction to yield pyrazolo[3,4-b]pyrazines (4) and pyrazolo[4,3-c]pyridazines (7), respectively, in acceptable to good yields. The reaction was found to be accelerated by using acidic or basic conditions. Quantum chemical calculations suggest the key step of the mechanism to be a direct cyclization; analysis of aromaticity based on computed magnetic properties revealed its medium-dependent pericyclic or pseudopericyclic character. The cyclization reaction has also been extended for the synthesis of related ring systems (9, 12, 14).

Original languageEnglish
Pages (from-to)3900-3906
Number of pages7
JournalJournal of Organic Chemistry
Volume73
Issue number10
DOIs
Publication statusPublished - May 16 2008

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Pyrazoles
Cyclization
Pyridazines
Magnetic properties

ASJC Scopus subject areas

  • Organic Chemistry

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A new cyclization to fused pyrazoles tunable for pericyclic or pseudopericyclic route : An experimental and theoretical study. / Filák, László; Rokob, T.; Vaskó, Gyöngyvér Ágnes; Egyed, O.; Gömöry, A.; Riedl, Z.; Hajós, G.

In: Journal of Organic Chemistry, Vol. 73, No. 10, 16.05.2008, p. 3900-3906.

Research output: Contribution to journalArticle

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AU - Riedl, Z.

AU - Hajós, G.

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