Synthesis, Physicochemical Characterization, and Cytotoxic Activity of p-Methoxyphenyl and p-Fluorophenyl Maleanilic Acid Ligands and Their Corresponding Organometallic Chelates of Chromium Group

A new p-methoxyphenyl (ML) and p-fluorophenyl (FL) maleanilic acid bidentate ligands were green synthesized by a solvent-free reaction of equimolar amounts of aniline derivatives (4-methoxyaniline or 4-fluoroaniline) with maleic anhydride. Additionally, some mixed ligand organometallic chelates of Cr(0), Mo(0), and W(0) carbonyls were synthesized by the addition of the prepared ligand (L) as a primary ligand to the hexacarbonyl metals, in which carbonyl groups are secondary ligands in a 1:1 molar ratio. The structures of the novel chelates were characterized by elemental analyses, FT-IR, EI-MS, 1H-NMR spectroscopy, and thermal analyses. FL maleanilic acid free ligand and its chromium complex were screened for antitumor activity in vitro against cell lines of HCT-116 (human colon carcinoma), hepG-2 (human hepatocellular carcinoma), and MCF-7 (human breast carcinoma). The results obtained referred to a high antitumor activity of both FL novel ligand and its chromium organometallic chelates.