The Synthesis of 2,6-Diamino-9-ß-D-Arabinofuranosylpurine from Vidarabine by the Selective Nitration and Ammonolysis

A practical synthesis of 2,6-diamino-9-β-D-arabinofuranosylpurine from the commercially available vidarabine is reported. Treatment of fully protected vidarabine with 2,2,2-trifluoroacetic anhydride and tetrabutylammonium nitrate introduced a –NO₂ group in the C2 position in high yield. 2,6-Diamino-9-β-D-arabinofuranosylpurine was synthesised in three steps and 61% total yield after ammonolysis of the –NO₂ accompanied by removal of the benzoyl groups.