Collect. Czech. Chem. Commun. 1984, 49, 1713-1721

1,3-vs- 1,5-dipolar reactivity of 1-phenylmethyl-4N-acetylimino-1H-1,2,4-triazolium betain toward aromatic isothiocyanates

Peter Zálupský and Augustin Martvoň

Department of Organic Chemistry, Slovak Institute of Technology 812 37 Bratislava


The title betain was found to display both 1,3 and 1,5-dipolar reactivity, depending on reaction conditions. Whereas the reaction with aromatic isothiocyanates in nonpolar solvents produced cycloadducts in concerted manner stewise addition in dimethylformamide led to a single product, presumably with sevenmembered ring. An open-chain intermediate could be isolated and characterized.