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Updated: Jan 14, 2026

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
Synthesis of Benzimidazol-2-ones by Oxidative Cyclization Ring Closure of Amido-Urea Precursors
Maria Popescu1, Anamaria Hanganu1,2, Anca Paun1
1University of Bucharest, Faculty of Chemistry, Department of Inorganic and Organic Chemistry, Biochemistry and Catalysis, Research Centre of Applied Organic Chemistry, 90 Panduri Street, Bucharest RO-050663, Romania.
Abstract:
We describe herein the synthesis of novel benzimidazol-2-ones by oxidative cyclization of amido-urea precursors, using bis(acetoxy)iodobenzene. The role of the oxidative reagent and the formation of the benzimidazol-2-one products were demonstrated and supported by X-ray diffraction. Optimization of the reaction conditions was performed, and the generality of the reaction was shown. The reaction scope was found to be limited to amino-urea substrates bearing a C(sp3) atom adjacent to the amide carbonyl group. A mechanistic pathway involving a Hofmann rearrangement was proposed.
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