N6-Naphthalenemethyl-2'-methoxybenzamido-beta-NAD+, a derivative of a low micromolar first-generation inhibitor of trypanosomal glyceraldehyde phosphate dehydrogenase (GAPDH), was synthesized, taking advantage of methodology for the selective phosphitylation of nucleosides. The compound was found to be a poor alternate cosubstrate for GAPDH, but an extremely potent inhibitor. Although intended for use in crystallization trials, the analogue presents possibilities for further drug design.