Reagents
and conditions: (i)
DBU, DMF, 60 °C, 16 h, 48%; (ii) MeOH/NH3, 80 °C,
16 h, 88%; (iii) POCl3, TEP, 0 °C, 1 h, 72%; (iv)
morpholine, dipyridyl disulfide, PPh3, DMSO, rt, 1 h then
β-NMN+, MgSO4, 0.2 M MnCl2;
(v) NADase, Tris buffer (0.1M, pH 7.3), rt, 81% for steps iv–v.