Quantum chemical studies of mechanisms of organic reactions: VI. Reaction of ethane-1,2-dithiol with vinylidene chloride

A theoretical mechanism has been proposed for the reaction of vinylidene chloride with ethane-1,2-dithiol in the system hydrazine hydrate–potassium hydroxide on the basis of DFT quantum chemical calculations at the B3LYP/6-311++G(d,p) level of theory. The reaction includes two consecutive stages: dehydrochlorination of vinylidene chloride to chloroacetylene and nucleophilic addition of one thiol group of ethane-1,2-dithiol to the β-carbon atom of chloroacetylene, followed by closure of 2,3-dihydro-1,4-dithiine ring via nucleophilic substitution of chlorine by sulfur atom of the second thiol group.