Previously, we synthesized and evaluated several thienopyrimidine derivatives containing heterocyclic ring substituents linked to the pyrimidine-2-thione nucleus at C-2 by a two-to four-atom spacer as potential anti-HIV-1 and antimicrobial agents. Also, from the literature, S- substituted pyrimidin-4-ones A and B exhibited interesting anti-HIV-1 activity. To further investigate the synthesis, tools and biological activities, we synthesized several new ...