The solvents were purified according to the standard procedures. All the starting materials were available from Enamine Ltd. or purchased from other commercial sources. Melting points were measured on MPA100 OptiMelt automated melting point system. 1 H, C{H} and F{H} NMR spectra were recorded on a Bruker 170 Avance 500 spectrometer (at 500 MHz for 1 H NMR, and 126 MHz for C{H} NMR) and Varian Unity Plus 400 spectrometer (at 400 MHz for 1 H NMR, 101 MHz for C{H} NMR, and 376 MHz for F{H} NMR). NMR chemical shifts are reported in ppm (δ scale) downfield from TMS as an internal standard and are referenced using residual NMR solvent peaks at 7.26 and 77.16 ppm for 1 H and 13 C{ 1 H} in CDCl3, 2.50 and 39.52 ppm for 1 H and 13 C{ 1 H} in DMSO-d6, 4.79 for 1 H in D2O. Coupling constants (J) are given in Hz. Spectra are reported as follows: chemical shift (δ, ppm), multiplicity, integration, and coupling constants (Hz). Elemental analyses were performed at the Laboratory of Organic Analysis, Department of Chemistry, Taras Shevchenko National University of Kyiv. Mass spectra were recorded on an Agilent 1100 LCMSD SL instrument (chemical ionization (CI)) and GCMS instrument (electron impact ionization (EI)). All experiments on the antiviral activity were performed at the compound concentration range of 0.048-150 µM in DMSO. BK virus (cell strain: Gardner; assay: quantitative polymerase chain reaction (DNA) / CellTiter-Glo (toxicity); cidofovir as a reference); herpes simplex virus 1 (cell strain: E-377; assay: CellTiter-Glo (cytopathic effect/toxicity); acyclovir as a reference); Varicella-Zoster virus (cell strain: Ellen; assay: CellTiter-Glo (cytopathic effect/toxicity); acyclovir as a reference); human papillomavirus (cell strain: HE611260.1; assay: Nano-Glo Luciferase (Nanoluc) / CellTiter-Glo (toxicity); 9-[2-(phosphonomethoxy)ethyl]guanine as a reference) were used as the test systems for the screening.