ИСТИНА

Synthetic accessibility and high reactivity of 4-fluoro substituted heterocycles in SNAr processes allowed obtaining new types of heterocyclic structures, namely, 4-azido- and 4-cyanopyrimidine N-oxides, representing excellent precursors for the functionalization via CuAAC reactions affording polyheterocyclic structures with potential biological activity. The optimal conditions for the 1,3-dipolar cycloaddition of 4-azido pyrimidine N-oxides with aromatic and aliphatic acetylenes and of 4-cyanopyrimidine N-oxide II with sodium azide were found. A series of previously unknown 4-triazolyl and 4-tetrazolylpyrimidine N-oxides was synthesized in the optimized conditions. The possibility of further functionalization of heterocycles via condensation with aromatic aldehydes was demonstrated as well. In summary, previously unknown types of heterocyclic compounds, containing both pyrimidine oxide and triazole or tetrazole moieties, were obtained to study their biological antiviral and anticancer) activity.