Enhanced anti-cancer activities of some derivatives of titanocene dichloride

The compounds ( η 5-C 5H 5) 2TiCl 2 ( I), currently undergoing phase II trials, ( η 5-C 5H 5)( η 5-C 5H 4CO 2Me)TiCl 2 ( II) and ( η 5-C 5H 4CO 2Me) 2TiCl 2 ( III) are assessed for their efficacies against a small lung cancer cell line. It is found that the introduction of the electron withdrawing carbomethoxy group into the cyclopentadienyl rings increases the effectiveness of this class of drugs, such that III compares favorably with the well known cisplatin.