Aza The Denitrification Purine Nucleoside Derivative Synthesis Research

The synthesis of natural nucleoside analogues has been being an active field for pharmaceutical chemists. Many nucleosides of purine derivatives possess high biological activities. 7-Deazapurine nucleoside has been separated from nature, determined and synthesized. It can replace natural purine nucleoside in many enzyme reaction systems of cell, and shows strong inhibitting action on the synthesis of natural purine bases. 1-De-azapurine nucleoside and 3-deazapurine nucleoside have been synthesized. 1-Azapurine nucleoside and 8-azapur-ine nucleoside have also been synthesized and all possess anti-cancer activities. 6-Thiopurine has been used as anti-cancer drug for many years.So far, all anti-cancer drugs used have low sele-ctivities towards cancer cells and normal cells. The searching for drugs which have high biological activities on cancer cells and have low poison effects on normal cells has been being an entising subject in the field of drug synthesis. Many derivatives of 1,2,4-triazine have biological activitives. 3,5-dioxo-2,3,4,5-tetra-hydro-1,2,4-triazine has anti-cancer activity.If the 6-C in the ring is replaced by N, the distribution of electron density of purine ring must be changed. We wish that this change will be able to make such compounds have better selectivity to cancer cells and normal cells, in order to get new drugs which have high anti-cancer activity and low poison effect on normal cells.In the view of metabolism of nucleosides, based on the literature on hand, We designed the following three kinds of nucleosides as aim compounds.