Thiadiazole derivatives of 2H –pyrido[1,2-a]pyrimidin-2-ones were synthesized, characterized by IR and NMR and were screened for their antibacterial activity against Escherichia coli and Staphylococcus aureus and compared with standard drug ciproflaxin. The ClogP, solubility drug likeliness and the mutagen city properties were computed using chem. draw, molinspiration and OSIRIS software’s. the compounds possessed a positive value for drug likeliness properties.