The current study reports design and diversity oriented synthesis of novel heterocycles incorporating of thioureido linkage on position no C-4 which not yet been explored and could find new applications in biology. Employing reagent based skeletal diversity approach; a facile synthesis of heterocycles with thioureido linkage at C-4 position of the quinazoline moiety has been accomplished. All the newly synthesized compounds were subjected to in vitro screening against various mycobacterial, bacterial and fungal strains. The bioassay results indicate some compounds could be emerged as the most promising anti tubercular and antimicrobial agents. All the intermediates and products have been isolated and fully characterized by IR, 1H NMR and 13C NMR.