Electrochemical Synthesis of Metanilic Acid

The preparative electrosynthesis of m-aminobenzenesulfonic acid (metanilic acid) from m-nitrobenzenesulfonic acid is studied under galvanostatic conditions on a nickel cathode in ammonia buffer. The technological parameters of electrosynthesis of metanilic acid determined on an enlarged laboratory setup in the ammonia buffer (0.4 М NH4Cl + NH4OH) with рН 7.5 the product yield on the substance of 93.8–94.0%, the current efficiency of 54.5–60.2, provide the substance yield 78.0–80.0%, the energy consumption of 10.2–11.3 kW h/kg, and the performance of electrolyzer of 0.36–0.40 kg/(m2 h) at the current density of 10 A/dm2 and the temperature of 55–60°С.