Lead-catalyzed synthesis of Azo compounds by ammonium acetate reduction of aromatic nitro compounds

Lead/ammonium acetate is a convenient reagent for the reduction of aromatic nitro compounds' to the corresponding symmetrically substituted azo compounds. Various azo compounds containing additional reducible substituents such as halogen, nitrile, acid, phenol, ester, methoxy, etc., functions have been synthesized in a single step by the use of this reagent. The conversion is reasonably fast, clean, high yielding and occurs at room temperature in methanol