Baker’s Yeast-Mediated Regioselective Reduction of 2,4-Dinitroacylanilines: Synthesis of 2-Substituted 6-Nitrobenzimidazoles

Several 2,4-dinitro-N-acylanilines were regioselectively reduced at the C-2 position by baker’s yeast in slightly basic media (pH = 7.5) to afford 2-amino-4-nitroacylanilines, which were then cyclized under acidic conditions to the corresponding 2substituted-6-nitrobenzimidazoles. The benzimidazoles thus obtained can be employed as precursors for bioactive derivatives.