Synthesis of 8-Aza-3-deazaisoguanosine by a Novel Ring Closure of Dinitriles by Sodium Alkoxides

This communication describes a convenient, direct ring closure of a novel 4-cyano-5-cyanomethyl-1-(β-D-ribofuranosyl)-1,2,3-triazole under basic conditions into 4-amino-6-alkoxy-1-(β-D-ribofuranosyl)-1,2,3-triazolo[4,5-c]pyridine, which can be easily transformed to 8-aza-3-deazaisoguanosine