A Simple Synthesis of New 2-Thioxoimidazolidine-4,5-dicarboxylates from Vicinal Diisothiocyanatocarboxylates

Abstract

A simple synthesis of novel symmetrical and unsymmetrical 2-thioxoimidazolidine-4,5-dicarboxylates is described. The symmetrical 2-thioxoimidazolidine-4,5-dicarboxylates were obtained through partial hydrolysis of vicinal 2,3-diisothiocyanatocarboxylates. The unsymmetrical 2-thioxoimidazolidine-4,5-dicarboxylates were prepared by addition of a stoichiometric amount of primary and secondary amines to vicinal 2,3-diisothiocyanatocarboxylates. The resulting imidazolidine derivatives were found to be convenient reactants for the construction of a new bicyclic imidazo[2,1-b]thiazole system. The addition of a twofold excess of amine to vicinal 2,3-diisothiocyanatocarboxylates gave rise to competitive condensations yielding bi-imidazolidine and bi-1,2,4-triazine derivatives.