Synthesis of ammonium S–S bond linked dipyridinedionates via four-component reactions of cyanoacetamide, aldehyde, amine and 1,3-thiazolidinedione

An unprecedented and efficient synthetic protocol for polysubstituted ammonium S–S bond linked 2,6-pyridinedionates was developed via the novel four-component reactions of 1,3-thiazolidinedione, aromatic aldehydes, secondary amines and cyanoacetamide in acetonitrile. A feasible explanation is given based on the characteristic ring-open and recyclization properties of 1,3-thiazolidinedione.