Novel PMP, PME and HPMP and related compounds containing N-6 substituted 2,6-diaminopurine and adenine bases are provided. These compounds are useful in a variety of utilities, including as intermediates in the preparation of flame retardants, diagnostic reagents and therapeutics, including antivirals. Of particular note are compounds otherwise not known to possess anti-DNA viral activity that become potent inhibitors of DNA viruses upon substitution of the N-6 site, thereby providing a novel and unexpected and surprising use for such compounds.