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 thienopyrimidine derivatives derived from thieno[2,3-d]-pyrimidine-2,4-dithione (3a,b) The compounds were designed to comprise the heterocyclic substituents directly linked to the thienopyrimidines nucleus at C-2. Moreover, various related triazolo[4,3-a]benzothieno[2,3-d]pyrimidines derived from 2-thioxothienopyrimidine were also prepared as isosteres. Among the synthesized derivatives 3-18, the compounds 3a, 8a, 10a, 13a and 14a were showing complete inhibition at 128 mg/mL or less.