Used in the synthesis of pharmaceuticals, particularly in the production of antithyroid drugs and certain antibiotics. Serves as a key reagent in organic chemistry for the preparation of heterocyclic compounds. Employed in electroplating processes to improve the brightness and smoothness of metal surfaces, especially in silver and copper plating. Acts as a stabilizer and curing agent in the manufacture of resins and rubber. Utilized in photographic processing as a developing agent and in textile finishing to enhance flame resistance. Also applied in analytical chemistry for the detection and separation of certain metal ions.