The compound has been produced by many methods. Industrially, MBT is synthesised by the Kelly process (U.S. Pat. No. 1,631,871), whereby Sulfur, aniline and carbon disulfide are reacted under elevated pressure at elevated temperatures in a batch reactor. The industrial route entails the high temperature reaction of
aniline and
carbon disulfide in the presence of sulfur, which proceeds by this idealized equation: : The traditional route is the reaction of
2-aminothiophenol and carbon disulfide: : This method was developed by the discoverer of the compound, A. W. Hoffmann. Other routes developed by Hoffmann include the reactions of carbon disulfide with 2-aminophenol and of
sodium hydrosulfide with chlorobenzothiazole. Further synthetic advances were reported in the 1920s that included demonstration that phenyl
dithiocarbamates pyrolyze to benzothiazole derivative. Industrially, MBT purification consists of a reprecipitation, wherein crude MBT is dissolved in sodium hydroxide solution, tar-like by-products are decanted off, filtered off or extracted. The aqueous sodium MBT solution is subjected to a further oxidative treatment, if appropriate; the MBT is then precipitated using sulfuric acid and filtered off (cf. German Patent 2,258,484). Unless captured, H2S escapes from the reaction upon completion of the reaction. The mechanism of the reaction and identification of by-products was clarified by
Neal Stuart Isaacs and
Fyaz Mahmood Daud Ismail, his postdoctoral colleague, working at Reading University between 1989 and 1991 This process has been converted from batch to flow and optimised using chemometric methods. Shandong Yanggu Huatai Co., Ltd., is operating this optimised process at a 10,000-ton-scale MBT production plant. The simulation results allowed optimisation to a green synthesis of MBT, with optimal industrial production and, therefore, reducing pollution from this important industrial process. ==Reactions==