| 摘要 |
<p>A process for synthesizing 2, 4-diamino benzene sulfonic acid, which comprises the following step: reacting m-phenylenediamine and sulfuric acid or oleum in a solvent at the temperature of 140-250°C to obtain 2,4-diamino benzene sulfonic acid, said solvent being one or more solvents selected from inorganic solvent phosphoric acid or polyphosphoric acid and organic solvent having a boiling point above 140°C under the normal pressure. A preparation process of 2,4-diamino benzene sulfonate, which comprises the following steps: obtaining 2, 4-diamino benzene sulfonic acid by the above-mentioned process, then conducting the salt forming reaction to obtain 2, 4-diamino benzene sulfonate. The present invention can effectively resolve the environmental problem caused by large amount of sulfuric acid and high cost problem, together with high yield and quality.</p> |
