Organomercury compounds. XII. The synthesis of diarylmercurials and arylmercuric arenesulphinates by sulphur dioxide elimination reactions

Abstract

The diarylmercurials, R₂Hg [R = Ph, p-XC₆H₄ (X = Me, Br, Cl, or F), 2,3,4-Cl₃C₆H₂, 2,4,5-Cl₃C₆H₂, 2-naphthyl, or 8-quinolyl], have been prepared in satisfactory yield by sulphur dioxide elimination reactions on heating the corresponding mercuric arenesulphinates under vacuum, but decomposition of mercuric p-acetamidobenzenesulphinate gave acetanilide. The mercuric arenesulphinates were obtained by reaction of mercuric acetate with the appropriate sodium arenesulphinates in aqueous solution at room temperature. Similar reactions in boiling aqueous solution gave either diarylmercurials, R₂Hg [R = Ph, p-XC₆H₄ (X = Me, F, or MeCONH), 2,4,6-Me₃C₆H₂, 2,4,6-(Me₂CH)₃C₆H₂, or 8-quinolyl], or arylmercuric arenesulphinates, RHg(0₂SR) [R = p-XC₆H₄ (X = Br or Cl), 2,3,4-Cl₃C₆H₂, 2,4,5-Cl₃C₆H₂, or 2-naphthyl], usually in low yield, and sulphur dioxide. Mercury-carbon bond formation also occurred in reactions of mercuric acetate with sodium mesitylenesulphinate and 2,4,6-triisopropylbenzenesulphinate at room temperature, mesitylmercuric mesitylenesulphinate and bis(2,4,6- triisopropylphenyl)mercury, respectively, being obtained. The sulphur- oxygen stretching frequencies of the mercuric arenesulphinates are indicative of S-sulphinate coordination, whilst those of the arylmercuric arenesulphinates are consistent with unidentate O- sulphinate groups.