Collect. Czech. Chem. Commun. 1980, 45, 1692-1703

Reactions of α,β-unsaturated acyl isothiocyanates with phenylhydrazine

Peter Kutschya, Pavol Kristianb, Milan Dzurillab and Jaroslav Kováča

a Department of Organic Chemistry, Slovak Institute of Technology, 880 37 Bratislava
b Department of Organic Chemistry, Šafárik University, 041 67 Košice


3-(2-Furyl)propenoyl isothiocyanate or 3-phenylpropenoyl isothiocyanate react with phenylhydrazine to give an isomeric mixture of 1,4- and 2,4-disubstituted thiosemicarbazides which cyclize under alkaline conditions to the corresponding 1,3-disubstituted Δ3-1,2,4-triazoline-5-thiones and 1,5-disubstituted 3-mercapto-1,2,4-triazoles, respectively. The structure of the prepared substances was confirmed by independent syntheses. Methylation of isomeric triazoles as well as methylation followed by cyclization of the corresponding thiosemicarbazides afforded, respectively, 1,5-disubstituted 3-methylthio-1,2,4-triazoles and 1,3-disubstituted 5-methylthio-1,2,4-triazoles. The structure of the synthesized products is discussed on the basis of their IR, 1H-NMR and mass spectra.