New facile tandem route to oxo- and thioxo[1,2,4]triazolo[1,5-a]pyridinium salts

Roberta Palkó, Zsuzsanna Riedl, Orsolya Egyed, Laszlo Fabian, György Hajós

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16 Citations (Scopus)


2-Arylsulfanyl- and benzylsulfanylpyridinium N-arylimides (2), easily available from tetrazolo[1,5-b]pyridinium salts (1), participate in 1,3-dipolar cycloaddition with aryl isothiocyanates and aryl isocyanates to result in formation of fused thioxo- and oxo[1,2,4]triazolium salts (5 and 12), respectively. This transformation is interpreted as a regular 1,3-cycloaddition followed by spontaneous elimination of the aryl- or benzylsulfanyl group. Formation of these triazolium salts can be followed - under appropriate reaction conditions - by ring-opening reactions to afford some new triazolyldienes (6). Recognition of the intermediate participation of the thiolate anion along the pathway 1 ? 5 allowed elaboration of a simple procedure to 5 implying a tandem reaction sequence.
Original languageEnglish
Pages (from-to)7805-7812
Number of pages8
JournalThe Journal of Organic Chemistry
Issue number20
Publication statusPublished - 2 Sep 2006

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