Synthesis of Platinum Derivatives of Polymeric and Cyclic Phosphazenes

Polymeric and oligomeric, water-soluble anticancer derivatives have been synthesized by the reaction of [NP(NHCH3)2]n or [NP(NHCH3)2]4 with K2PtCl4. Two types of compounds were isolated. The first was formed in organic media in the presence of 18-crown-6 ether. The products contained a square planar platinum atom bonded to the nitrogen atoms of the phosphazene skeleton, as verified by the x-ray structure of PtCl2[N4P4(NHCH3)8]. The second type of derivative was formed in aqueous acid as the sait, [H2N4P4(NHCH3)g]2+[PtCl4]2_. The compounds showed tumor inhibitory activi-ty in initial anticancer screening tests. Related derivatives of formula PtCl2[N4P4(CH3)8] and [H2N4P4(CH3)8]2+[PtCl4]2-were formed when [NP(CH3)2]4 reacted respectively with PtCl2 in organic media or with K2PtCl4 in aqueous media.