Novel Acyclic Phosphonylated 1,2,3-Triazolonucleosides with an Acetamidomethyl Linker: Synthesis and Biological Activity

A new series of 4‐substituted [(1,2,3‐triazol‐1‐yl)acetamido]methylphosphonates as acyclic nucleotide analogs were synthesized from diethyl (2‐chloroacetamido)methylphosphonate via azidation followed by 1,3‐dipolar cycloaddition with selected alkynes derived from natural nucleobases or their mimetics. All compounds were tested for their antiviral activities against DNA and RNA viruses as well as for cytostatic activity or cytotoxicity. Among all tested compounds, [(1,2,3‐triazol‐1‐yl)acetamido]methylphosphonate 6e substituted with the N3‐Bz‐benzuracil moiety showed activity against the vesicular stomatitis virus (EC50 = 45 µM) in HeLa cell cultures. New 4‐substituted [(1,2,3‐triazol‐1‐yl)acetamido]methylphosphonates were synthesized as acyclic nucleotide analogs and tested for their antiviral activities against DNA and RNA viruses. [(1,2,3‐Triazol‐1‐yl)‐acetamido]methylphosphonate 6e (n = 1; R = N3‐Bz‐benzuracil) was found to be active against the vesicular stomatitis virus (EC50 = 45 µM) in HeLa cells.