Synthesis, Characterization And Properties Of Ferrocene-functionalized Triazolopyrimidine Derivatives

Triazolopyrimidines have attracted intense interest in recent years because of their diverse biological and pharmacological propertiesis,which plays important roles in the development of modern medicine.It consists of two important active structural units?triazole and pyrimidine?,and thus exhibits versatile pharmacological activities including antibacterial,anticonvulsant,anti-inflammatory,anti-malarial,anti-HBV and anti-tumor properties.Ferrocene has been confirmed to be valuable for biological applications due to their unique properities,especially reversible redox character,high stability,and low toxicity in vivo.Inspired by the promising activity of triazolopyrimidine and ferrocene,we report a series of new ferrocene-appended triazolopyrimidine derivatives with the aim to develop new potential antitumor agents.The UV-vis absorbtion properties,electrochemical properties and biological activities were investigated.1.Fifteen ferrocene-functionalized triazolopyrimidine derivatives FcL₁^FcL₅,FcL₆^FcL₁₀ and FcL₁₁^FcL₁₅ were synthesized and characterized by nuclear magnetic resonance spectroscopy,mass spectrometry,elemental analysis and infrared spectroscopy.Furthermore,crystal structures of two target compounds FcL₁ and FcL₁₃ were obtained.2.The electrochemical properties of triazolopyrimidines FcL₁^FcL₁₅ were studied by cyclic voltammetry and conventional pulse method.The results show that all the compounds can undergo reversible single electron redox reaction on the electrode surface,and the reaction is controlled by diffusion.3.The anti-tumor activity of 15 target compounds was tested.The results showed that FcL₁^FcL₅ had selective inhibition on human esophageal cancer cell line EC-9706,human esophageal cancer cell Eca-109 and human gastric cancer cell line SGC-7901.FcL₅ exhibited good inhibitory activity against EC-9706 and Eca-109,with IC₅₀values of 13.69 and 8.98?M,respectively.FcL₂ exhibited good inhibitory activity against SGC-7901(IC₅₀=5.79?M/L).Anti-tumor effect of FcL₁^FcL₅ is better than that of FcL₆^FcL₁₀ and FcL₁₁^FcL₁₅.In addition,the compound bearing methyl group is superior to other compounds in anti-tumor.