We report on preparation of potential nucleoside phosphonate prodrugs: 1-{3-hydroxy-2-[О-(adamantylalkyl)phosphorylmethoxy]propyl}cytosines containing two structural fragments providing antiviral activity, nucleoside phosphonate and adamantyl sites.Nucleoside phosphonates (adefovir, cidofovir, tenofovir, and their analogs) are promising antiviral drugs of the new generation. These compounds has shown high efficacy against genomic DNA viruses [1-4] confirmed on a set of experimental models in vitro and in vivo [5][6][7][8][9].