Condensed quinazolines like thiadiazolo quinazolines and corresponding bioisostere thiadiazolo thienopyrimidines were found to be biologically active molecules. An attempt was made to utilize the concept of bio-isosterism for the synthesis of 3-amino2- mercapto5, 6, 7, 8-tetrahydro-benzo (b)thieno-(2,3-d)-pyrimidine-4-(3H)-ones which was further treated with acetylchloride, urea, carbondisuiphide, chloroacetic acid, benzoin to affords novel fused thiadiazole, thiadiazine compounds. The novel synthesized compounds were characterized by MP, IR, 1H NMR spectra. These synthesized compounds were subjected to anti-microbial studies using few gram-positive, gram-negative and fungal organisms. The standard drug used for anti-microbial activity was ampicillin and ketoconazole respectively and also tested for their anti-cancer activity by MTT assay method. The tested compounds exhibited significant antimicrobial and anti-cancer activity.
Benzothienopyrimidines, Thiadiazoles, Thiadiazines, Anti-microbial activity, Anti- cancer activity