Antitumor activity of organotin compounds. Reaction,synthesis and structure of Et2SnCl2(phen) with 5-fluorouracil

The antitumor agent Et₂SnCl₂(phen) (phen = phenanthroline) reacts with 5-fluorouracil (UF) to form Et₂Sn(phen)UF)Cl by a basic catalytic process. The reaction may be characterized as nucleophilic attack on H⁺N(3) in the 5-fluorouracil ring by the cis-chloro in Et₂SnCl₂(phen). The product has been identified by microanalysis, IR, UV and NMR spectra and these results are consistent with the expected complex. The binding of the 5-fluorouracil ligand to the cis-chloro in Et₂SnCl₂(phen) not only enhances the antitumor activity of the complex, but also promotes studied aimed at understanding the mechanism of drug action.