Ar. Pagano et al., SYNTHESES OF [6,7-N-15]-ADENOSINE, [6,7-N-15]-2'-DEOXYADENOSINE, AND [7-N-15]-HYPOXANTHINE, Journal of the American Chemical Society, 117(47), 1995, pp. 11669-11672
We have developed a high-yield route for the synthesis of [7-N-15]-hyp
oxanthine in four steps in an overall yield of 81%. This procedure use
s [N-15]-sodium nitrite as the N-15 source and an inexpensive pyrimidi
ne to provide an economical route to this useful N-15-labeled intermed
iate. Conversion to [7-N-15]-6-chloropurine followed by enzymatic tran
sglycosylation gives the corresponding ribo- and 2'-deoxyribonucleosid
es. Ammonolysis of the 6-chloro moiety to give the [6,7-N-15]-labeled
nucleosides is effected simply and in high yield using 2 equiv of [N-1
5]-ammonium chloride and 3 equiv of potassium bicarbonate.