Syntheses of [1-15N]-2'-deoxyinosine, [4-15N]-2'-deoxyAICAR, and [1-15N]-2'-deoxyguanosine

A high-yield synthesis of [1-N-15]-2'-deoxyinosine (5), [4-N-15]-2'-deoxy AICAR (7), and [1-N-15]-2'-deoxyguanosine (10) from 2'-deoxyinosine (1) using relatively low expensive (NH3)-N-15 as N-15 source is described. The method exploits 2-C reactivity of 2'-deoxyinosine (1) to obtain its N-15-labelled counterpart, through [1-N-15]-2'-deoxyinosine (5), and successively, [4-N-15]-2'-deoxyAICAR (7). [1-N-15]-2'-Deoxyguanosine (10) can be prepared as well, through an improved cyclization procedure. No protection of sugar hydroxyl groups is required at any stage.