Hydroxynaphthoquinone Metal Complexes as Antitumor Agents X: Synthesis, Structure, Spectroscopy and In Vitro Antitumor Activity of 3‐Methyl‐Phenylazo Lawsone Derivatives and Their Metal Complexes Against Human Breast Cancer Cell Line MCF‐7

The C-3 substituted phenylazo derivatives of lawsone (2-hydroxy-l,4 p-naphthoquinone, III) were synthesized and characterized. The X-ray crystal structure was determined for the ligand 3-(3'-methyl phenylazo) lawsone. The copper complexes of these derivatives were found to possess 1:2 metal stoichiometry and square planar geometries with intermolecular stackings, resulting in antiferromagnetic exchange interactions. The in vitro activity of all the synthesized compounds was examined against human breast cancer cell-line, MCF-7, which revealed enhanced activities for the metal complexes, the highest activity being observed for the copper compound of 3-(3'-methyl phenylazo) lawsone.