In the search for new anticancer drugs. 9. Synthesis and anticancer activity of spin-labeled analogs of N,N:N',N':N",N"-tris(1,2-ethanediyl)phosphoric triamide and N,N:N',N':N",N"-tris(1,2-ethanediyl)phosphorothioic triamide
A number of N,N:N'',N'':N",N"-tri-1,2-ethanediylphosphoric triamide (TEPA) and N,N:N'',N'':N",N",-tri-1,2-ethanediylphosphorothioic triamide (thioTEPA) derivatives containing 2 aziridine moieties or 2 (2-chloroethyl)amino functions and either a 2,2,6,6-tetramethylpiperidine, 1-oxy-2,2,6,6-tetramethylpiperidine or 1-hydroxy-2,2,6,6-tetramethylpiperidine component were synthesized and tested against [mouse] lymphocytic leukemia P388 in mice. In a structure-activity comparison at optimum dose all compounds containing the nitroxyl radical were more active than the corresponding hydroxylamine derivatives. The open-chain compounds were less active than the corresponding aziridine ring compounds. The replacement of the X = bridge in the axiridine ring compounds with the X = N(CH3) group resulted in lowering of the anticancer activity.