Reaction of 6Н-5-(4-Fluorophenyl)-3-(2-pyridyl)-1,2,4-triazine with 4,5-Difluoro-1,2-dehydrobenzene

The reaction of C⁶-unsubstituted 5-aryl-3-(2-pyridyl)-1,2,4-triazine with generated in situ difluoroaryne intermediate (4,5-difluoro-1,2-dehydrobenzene), previously unused for this aim, was studied. New transformations of the 1,2,4-triazine nucleus were discovered, which lead, along with the domino transformation product (10-(1,2,3-triazole-3-yl)pyrido[1,2-a]indole) natural for this transformation, to the formation of unexpected products, namely 1,3,5-tris-substituted 1,6-dihydro-1,2,4-triazin-6-ol and 1H-1,2,4-triazole. The structure of the products was confirmed by physicochemical methods, including X-ray diffraction analysis.