Tumor inhibitory triazenes. 2. Variation of antitumor activity within an homologous series

An homologous series of water-soluble, chemically stable analogues of 5-(3,3-dimethyl-1-triazeno)imidazole-4-carboxamide (DTIC) has been prepared with activity comparable to DTIC in an experimental tumor system. The antitumor activity of this series of 3-alkyl-1-(4-carboxyphenyl)-3-methyltriazenes rapidly diminishes at alkyl chain lengths greater than pentyl. Partition coefficients were determined, but no relationship between these and antitumor activity could be established.