The Reduction Of Diaryl Disulfides(Diselenides) By Iron Dust And Its Application Study

Diaryl disulfides(diselenides) are important intermediates of organic reactions.Currently, most methods for the reduction of diaryl disulfides(diselenides) werereported, but some require the use of expensive transition metal as reductant. Iron is arelatively cheap transition metal, the paper intend to use iron as a reductant to restorediaryl disulfides(diselenides) and its application in the synthesis of-arylthio(seleno)carbonyl compounds. Details are as follows:(1) First, diphen l disulfide (diselenide) reacted with-bromo ethyl ether wasused as a model. Experimental results showed that in the presence of iron dust, thereaction could occured and produced-phenylthio(seleno) ethyl ether. We studied theeffect of solvent, time, temperature and the amount of iron dust on the reaction. Theresults showed that the optimized conditions are: DMF as solvent, the reaction time ofdiphenyl disulfide is15h, the reaction time of diphenyl diselenide is12h, undernitrogen protection, the reaction temperature is90℃and the molar ratio of iron dustand diphenyl disulfide (diselenide) is6:1. We studied the effect of the differentsubstituent group of diaryl disulfide(diselenide) on the reaction, the results showedthat the ield of-arylthio(seleno) esters with electron-withdrawing substituents (suchas chlorine) is higher than-arylthio(seleno) esters with electron-donatingsubstituents. The ield of-phenylthio ethyl ether is77%-95%, the yield of-phenylthio propionic ether is68%-90%, the ield of-phenylseleno ethyl ether is79%-96%, the ield of-phenylseleno propionic ether is72%-86%.(2) Under these optimized conditions, we studied the reaction of differentsubstituent group of diaryl disulfide(diselenide) with-bromo acetone and-bromoacetophenone, the results showed that the ield of-arylthio(seleno) acetone is higherthan-arylthio(seleno) acetophenone. The yield of-arylthio acetone is69%-79%,the yield of-arylthio acetophenone is34%-49%, the yield of-arylseleno acetone is67%-84%, the yield of-arylseleno acetophenone is29%-45%.In this paper, we studied the reduction of diaryl disulfides(diselenides) by irondust, and then reacted with-bromo carbonyl compounds to get-arylthio(seleno)carbonyl compounds. The reaction condition is mild and easy to operate, and avoidedthe use of those materials, which are malodorous, toxic and difficult to prepare. The paper provides a new and simple operation method for the synthesis of-arylthio(seleno) carbonyl compoundsAll target molecular structures of this paper have been confirmed by1H NMR,13C NMR and MS characterization.