This invention relates to compounds based on the 3-deazapurines ring system and to methods for making such compounds. The invention also generally relates to the field of "antisense" agents, agents that are capable of specific hybridization with a nucleotide sequence of an RNA. The 3- deazapurine-containing compounds of this invention can be useful for modulating the activity of RNA when incorporated into oligonucleotides. Oligonucleotides and their analogs are used for a variety of therapeutic and diagnostic purposes, such as treating diseases, regulating gene expression in experimental systems, assaying for RNA and for RNA products through the employment of antisense interactions with such RNA, diagnosing diseases, modulating the production of proteins and cleaving RNA in site specific fashions.