Facile Access to Bromonucleosides Using Sodium Monobromoisocyanurate (SMBI)

Bromonucleosides constitute a significant class of molecules and are well known for their biological activity. 5‐Bromouridine, 5‐bromo‐2′‐deoxyuridine, 5‐bromouridine‐5′‐triphosphate, and nucleotides containing 5‐bromouridine have been tested and used for numerous biological studies. 8‐Bromopurine nucleosides have been used as essential precursors for the synthesis of nucleosides with fluorescent properties. This unit describes protocols for the synthesis of bromonucleosides using sodium monobromoisocyanurate (SMBI) in a straightforward way. Reactions are carried out at room temperature, and aqueous solvent mixtures are used to dissolve the nucleosides. Sodium azide is used as catalyst for the bromination of pyrimidine nucleosides, and no catalyst is necessary for the bromination of purine nucleosides. Unprotected 2′‐deoxy pyrimidine and 2′‐deoxy purine nucleosides are treated with SMBI to afford C‐5 bromo pyrimidine and C‐8 bromo purine nucleosides, respectively. This methodology has been found to be efficient for the synthesis of bromonucleosides on gram scale with consistently high yields. © 2017 by John Wiley & Sons, Inc.