Synthesis and Cytotoxic Evaluation of Substituted Urea Derivatives as Inhibitors of Human‐Leukemia K562 Cells

A series of substituted urea derivatives, compounds 1-14, were synthesized and evaluated for their cytotoxic activities against the human-leukemia K562 cell line. Two structurally simple compounds, 7 and 12, both incorporating a morpholine ring, were found to be highly active, with IC50 values of ca. 0.25 microM.