Unexpected Formation of 5‐Nitro‐1H‐benzimidazoles by Nucleophilic Recyclization of 1‐Methyl‐5‐nitropyridinium Salts

Abstract

The synthesis of substituted 5‐nitro‐2‐phenyl‐1H‐benzimidazoles has been described via domino anionic process rearrangement of 3‐benzoylamino‐1,2‐dimethyl‐5‐nitropyridinium salts in the presence of NaOH water–alcohol solution. Substituted N‐benzoyl‐o‐phenylenediamines was obtained via recyclization of 3‐benzoylamino‐1,2‐dimethyl‐5‐nitropyridinium salts in the presence of aqueous methylamine solution.