BACKGROUND: 2,2'-disbenzothiazole disulfide is widely used as a vulcanization accelerator in rubber production and as an intermediate in the drug industry. Its current industrial process, the oxidation of 2-mercaptobenzothiazole by sodium nitrite in acidic solution, produces large quantities of liquid waste water. A novel and green synthetic method was developed, which used dioxygen as the oxidant and 2,2,6,6-tetramethylpiperidyl-1-oxyl (TEMPO) as the catalyst without any metallic compounds. RESULTS: The conditions, including temperature, solvents, amount of catalyst, dioxygen pressure and time, were optimized. Thus 94% yield of 2,2'-disbenzothiazole disulfide was obtained at 60 degrees C in acetonitrile under 0.2 MPa oxygen pressure for 3 h. Theoretical calculations and UV spectra showed that hydrogen-transfer reaction between 2-mercaptobenzothiazole and TEMPO was the key step, and 2,2'-disbenzothiazole disulfide was generated by the coupling of the formed thiyl radical of 2-mercaptobenzothiazole. CONCLUSION: 2,2'-disbenzothiazole disulfide was prepared efficiently by aerobic oxidative coupling of 2-mercaptobenzothiazole with TEMPO as the catalyst. This 'environmentally friendly' approach with easy handling, mild reaction conditions and simple separation represents a viable means of producing 2,2'-disbenzothiazole disulfide. (C) 2011 Society of Chemical Industry