Novel derivatives of 5-(substituted)benzylidene-3-(4-substituted)phenylsulfonylimidazolidine-2,4-diones (3a-r), 1-(4-substituted)phenylsulfonyl-3-(4-substituted)phenylpyrimidine-2,4,6-(1H,3H,5H)-triones (6a-l), and 3-(4-substituted)phenyl-1-(4-substituted)phenylsulfonylquinazoline-2,4(1H,3H)- diones (8a-l) have been synthesized and tested for their antitumor activity against 60 tumor cell lines taken from 9 different organs. The tested compounds have showed good inhibitory effect at the ovarian cancer (IGROV1) cell line. A significant inhibition for (RXF393) renal cancer cells was observed with series 3 compounds, while in the other two series 6 and 8, there was a significant inhibition of ovarian cancer cells (OVCAR-8) and melanoma cells (SK-MEL-2). Interestingly; beside the strong inhibition of compound 3q to IGROV1 and RXF393 cells, a great inhibition (199.62%) for (M14) Melanoma cells was observed at the tested concentration (10 卩. ADME-T and pharmacophore prediction methodology were used to study the antitumor activity of the most active compounds and to identify the structural features required for antitumor activity.