Synthesis of a New Series of Phosphonylated 1,2,3-Triazoles as Acyclic Analogs of Ribavirin

A novel series of phosphonylated 1,2,3‐triazoles as structural acyclic analogs of ribavirin, in which the 1,2,3‐triazole ring was substituted at C4′ with COOMe, CONH2, CONHOH, and CH2NHBoc groups, were synthesized from diethyl azidomethyl‐, 2‐azidoethyl‐, 3‐azidopropyl‐, 4‐azidobutyl‐, 2‐azido‐1‐hydroxyethyl‐, 3‐azido‐2‐hydroxypropyl‐, 2‐azidoethoxymethyl‐ and 2‐azidoethoxyethylphosphonate. The efficient synthesis of diethyl azidomethylphosphonate from diethyl 4‐nitrobenzenesulfonylmethylphosphonate employing the in situ formed azides is described. All synthesized compounds were evaluated in vitro for their inhibitory activity against a broad variety of RNA and DNA viruses. No antiviral activity was observed at 100 µM. Only compound 13g exhibited inhibitory effects on the proliferation of HeLa cells (IC50 = 169 ± 45 µM). A novel series of phosphonylated 1,2,3‐triazoles as structural acyclic analogs of ribavirin were synthesized and evaluated in vitro for their inhibitory activity against a variety of RNA and DNA viruses. No antiviral activity was observed at 100 μM. Only compound 13g exhibited inhibitory effects on the proliferation of HeLa cells with an IC50 of 169 ± 45 μM.