Synthesis of 2-tetrafluoropyridyl-4,5-disubstituted 1,2,3-triazoles

By cycloaddition reaction of sodium azide with chalcone in the presence of CuO as a catalyst in DMF a 1,2,3-triazole are prepared in reaction with pentafluoropyridine to give 2-(tetrafluoropyridin-4-yl)-1,2,3-triazole derivatives in good yields and high regioselectivity. The regioselectivity of the compounds are confirmed by F-19-NMR and other spectroscopy.