A waste-free packed-bed continuous-flow synthesis of disulfiram with a composite catalyst

Abstract

Disulfiram, a star molecule in the rubber, pharmaceutical and agrochemical industries, has been encountering multiple challenges for its conventional synthesis. In this work, a highly sustainable and efficient MoS₂-catalyzed continuous-flow synthesis of TETD has been developed, providing high yield and purity of products upon simple isolation. This process uses O₂ and ethanol as a green oxidant and solvent, without any sacrificing redox agent, rendering it fully atom-economic. The packed-bed filled with MoS₂ and the co-catalyst Ca(OH)₂ is low-leaching and reusable. The structurally similar rubber accelerator tetramethylthiuram disulfide (TMTD) was also synthesized using this method.