Abstract The synthesis and properties of the 5′-amino analog of adenosine diphosphate are described. The 5′-amino-5′-deoxyadenosine 5′-N-diphosphate (NADP) is prepared from the previously described aminonucleoside triphosphate by the hexokinase catalyzed transfer of the terminal phosphoryl to glucose. The NADP is stable in neutral or basic media, and is similar to natural ADP in chromatographic, electrophoretic, and spectrographic properties. Snake venom phosphodiesterase degrades NADP to the monophosphate NAMP, and acid degrades both NADP and NAMP to 5′-amino-5′-deoxyadenosine.