Alternative synthesis of N,N'-diphenylthiourea and its analysis by LC-MS

摘要

N,N'-Diphenylthiourea (DPTU) has been widely used during the past decades as medicine for leprosy, as a flotation agent to separate ferric sulfide from other metal sulfides, as a ligand to form N,N'-diphenylthioureido complexes with some metals such as ruthenium, osmium and iridium, as a curing accelerator for caoutchouc and synthetic rubber (especially for natural latex and neoprene), as an extractant for isolating precious metals and as a thermal stabilizer for PVC. IT also serves as an intermediate and a starting material for the preparation of diphenylguanidine, dyestuffs, curing bladder, rubber bag, tire cement, wires, cables, as a detergent for cleaning airport runways and many other commercial products. Therefore, extensive investigations have been carried out to devise an effective synthesis of DPTU and other N,N'-disubstituted thioureas. However, there still exist many practical limitations in current DPTU synthese and some problems in DPTU analysis.