Synthesis and Antitumor Activity of cis-Platinum Complexes of Aromatic Amines

cis-Platinum complexes of aromatic amines were synthesized in water or at the interfacial layer between water and an organic solvent. The position of substitution of aniline derivatives had a marked effect on the synthesis of the complexes. The coordination of 2-substituted anilines needed a long time and the yields were low. That of 3- or 4-substituted anilines was fast, and the yields were high. Disubstituted or N-substituted anilines needed fairly long reaction times and the yields were lower than those of monosubstituted anilines; sometimes unidentified complexes were obtained or no reaction product was formed.Six synthesized cis-dichloro platinum(II) complexes which coordinate bis(4-aminophenol), bis(3-toluidine), bis(2-aminobiphenyl), bis(4-sulfamidoaniline), bis(1-naphthylamine) and bis(4-phenylazo-1-naphthylamine) had high antitumor activities against Sarcoma 180 ascites in female ICR/JCL mice. The dose of platinum of these effective complexes given to the mice was in the range of 7.37-105.76 mg/kg (26.44%-39.96%). This result suggests that the toxicity of the platinum complexes might depend on their carrier ligands.