We report the first synthesis of beta-2'-deoxy[9-N-15] adenosine: the last of the singly labelled N-15 beta-21-deoxyadenosines to be synthesized. Using commercially available 5-amino-4,6-dichloropyrimidine and 2-10 equivalents of (NH3)-N-15, beta-2'-deoxy[9-N-15]adenosine has been constructed in four steps in good overall yield.