Synthesis of 3-amino- and 3-azidoanalogs of 9-(3-hydroxy-2-phosphonylmethoxypropyl)adenine (HPMPA)

Abstract

1-Azidopropane-2,3-diol (IIb) reacts with p-toluenesulfonyl chloride to give the tosyl derivative IIIa which, on acid catalyzed condensation with 2,3-dihydropyran, afforded 1-azido-2-(tetrahydropyran-2-yloxy-3-(p-toluenesulfonyloxy)propane (IIIb). Treatment of adenine sodium salt with IIIb resulted in the intermediate IV which was transformed by acid hydrolysis to 9-(RS)-(3-azido-2-hydroxypropyl)adenine (V). Catalytic hydrogenation of V led to 9-(RS)-(3-amino-2-hydroxypropyl)adenine (VI). 9-(RS)-(3-Azido-2-hydroxypropyl)-N6-benzoyladenine (VII) was obtained from V by chlorotrimethylsilane/benzoyl chloride treatment. Reaction of the compound VII with dimethyl p-toluenesulfonyloxymethanephosphonate (VIII) in the presence of excess sodium hydride, followed by alkaline hydrolysis, afforded methyl 9-(3-azido-2-phosphonylmethoxypropyl)adenine (IXa) which was transformed to the parent acid IXb by bromotrimethylsilane treatment. Hydrogenolysis of IXb yielded 9-(RS)-(3-amino-2-phosphonylmethoxypropyl)adenine (X).