Electrosynthesis of biologically active dicycloalkyl di- and trisulfides involving an H2S—S8 redox system

Abstract

Biologically active dicycloalkyl di- and trisulfides were prepared by the reactions of cycloalkanes C₅—C₇ with H₂S and S₈ under the anodic (cathodic) activation of hydrogen sulfide. In dichloromethane, the electrochemical activation of H₂S in the presence of sulfur can generate sulfur-centered radical intermediates that react with cycloalkanes at room temperature. The current yield of di- and trisulfides depends on the method of redox activation of hydrogen sulfide, the concentration of sulfur, and the time of electrosynthesis. The anodic activation of hydrogen sulfide in the synthesis of dicycloalkyl di- and trisulfides in an excess S8 is more efficient than the cathodic activation. In the series of cycloalkanes C₅—C₇, the highest yield of sulfur-containing products is observed for cycloheptane.