Formation of the dimethylbenzimidazole ligand of coenzyme B(12) under physiological conditions by a facile oxidative cascade

Org Lett. 2003 Jun 26;5(13):2211-3. doi: 10.1021/ol034530m.


Dimethylbezimidazole, the axial ligand of vitamin B(12), is synthesized from riboflavin by a two-electron oxidation, a retro-aldol condensation, and a second two-electron oxidation. This oxidative cascade readily takes place nonenzymatically under physiological conditions. [reaction: see text]

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Benzimidazoles / chemical synthesis*
  • Benzimidazoles / chemistry
  • Benzimidazoles / metabolism
  • Chromatography, High Pressure Liquid
  • Cobamides / metabolism*
  • Ligands
  • Oxidation-Reduction
  • Riboflavin / chemistry


  • Benzimidazoles
  • Cobamides
  • Ligands
  • 5,6-dimethylbenzimidazole
  • Riboflavin