Synthesis of 2-(arylthio)-3'-(alkyl- or dialkylamino)diphenyl sulfides via 5-arylthianthrenium perchlorates and their complexations with silver(I) and lead(II) ions

Abstract

Treatment of 5-arylthianthrenium perchlorates 2 with secondary alkylamines in the presence of LDA in THF at reflux gave 2-(arylthio)-3'-(dialkylamino)diphenyl sulfides 7 as major products along with 2-(arylthio)-2'-(dialkylamino)diphenyl sulfides 8 and thianthrene. The latter two compounds were formed depending on the structures of amines employed and the concentrations of LDA. It has been found that the methoxy groups of 7e, 7g, and 7h were displaced by amide ions in the presence of excess amounts of LDA to give the corresponding 2-(4-dialkylaminophenylthio)-3'-(dialkylamino)diphenyl sulfides (14a-c). The reactions with aza-15-crown-5, aza-18-crown-6, and 7, 16-diaza-18-crown-6 gave analogous products via a benzyne intermediate.The affinity of selected metal cations for compounds 7a, 7e-f, 7h, 7j, 7m, 10, 13a, and 18a was examined by an extraction method. The dialkylamino groups of 7a, 7e, 7f, and 7h increased somewhat the extractive abilities of Ag + ion (14 -28%) compared with that of 10 (8%), whereas compound 13a having a diisopropylamino group showed low (9%) and high (67%) extractive abilities toward Ag + and Pb 2+ ions, respectively. Compounds 7j and 7m having an aza-18-crown-6 moiety showed 67% and 66% extractive abilities toward Pb 2+ but 40% and 24% extractive abilities towards Ag + ions, respectively. However, compound 18a with two identical lariats showed high (86%) and low (12%) extractive abilities toward Ag + and Pb 2+ ions, respectively.