Synthesis and Antiviral Activity of 1,5-and 1,3-Dialkyl-1,2,4-triazole C-Nucleosides Derived from 1-(Chloroalkyl)-1-aza-2-azoniaallene Salts

Abstract

Reactions of α, α′-dichloroazo compounds 2 with SbCl₅ gave 1-(chloroalkyl)-1-aza-2-azoniaallene salts 3 as reactive intermediates. Cycloadditions of 3 with the ribofuranosyl cyanide 4 afforded the β-D-ribofuranosyl-1,2,4-triazolium salts 5, which rearranged spontaneously to salts 6. Hydrolysis of 6 gave the 1,2,4-triazole C-nucleosides 7, which yielded the free nucleosides 8 after deblocking. Analogously, 12 was prepared from the cycloaddition of 4 with the α-chloroazo compound 10 in the presence of SbCl₅. Deblocking of 12 with sodium methoxide afforded 13. Compounds 8a,b,e,f and 13 were tested against HIV-1, HIV-2, HSV-1 and HSV-2 and were found to be inactive.