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

Reactions of alpha, alpha'-dichloroazo compounds 2 with SbCl5 gave 1-(chlor oalkyl)1-aza-2-azoniaallene salts 3 as reactive intermediates. Cycloadditio ns of 3 with the ribofuranosyl cyanide 4 afforded the beta-D-ribofirranosyl -1,2,4-triazolium salts 5, which rearranged spontaneously to salts 6. Hydro lysis 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 cyclo addition of 4 with the alpha-chloroazo compound 10 in the presence of SbCl5 . Deblocking of 12 with sodium methoxide afforded 13. Compounds 8a,b,e,f an d 13 were tested against HIV-1, HIV-2, HSV-1 and HSV-2 and were found to be inactive.