A series of fluorinated bicyclic fused compounds, containing fragments of pyridine and 3,4-dihydro-2H-1,4-thiazine 1,1-dioxide were synthesized via one-pot substitution of halogen atoms by N-nucleophiles in polyfluorinated precursor. Formation of the heterocyclic moiety was proceed as a two-stage process starting from Br replacement at the side chain followed by intramolecular aminodefluorination. The structures of some of the obtained heterocycles were confirmed using X-ray diffraction analysis. In addition, their inhibitory activity against influenza A/Puerto Rico/8/34 (H1N1) virus in MDCK cell culture was evaluated and compound-leader was found.