Nucleophilic reactions of 5‐(aryl)thianthrenium bromides with sodium aryl oxides

Reactions between 5‐(aryl)thianthrenium bromides ( 1a – e ) with aryl (Ar) groups phenyl ( a ), p ‐tolyl ( b ), p ‐anisyl ( c ), p ‐chlorophenyl ( d ) and p ‐bromophenyl ( e ) and sodium aryl oxides ( 7a – c , Ar′ONa, Ar′ = phenyl, p ‐tolyl and p ‐chlorophenyl) were carried out in acetonitrile at 80 °C. Results are compared with those of earlier reactions of 1a – e with corresponding sodium aryl thiolates (Ar′SNa). In contrast with the thiolate reactions, those with 7a – c were too slow at room temperature to be useful. Reactions of 1a – c at 80 °C gave small amounts of benzene and toluene from 1a and b , small amounts of diaryl ethers ArOAr′ ( 9 ) and thianthrene (Th) and large amounts (90–97%) of 2‐(ArS)‐2′‐(Ar′O)diphenyl sulfide ( 10 ). Compared with reactions of 1a – c , those of 1d and e gave larger amounts (10–17%) of 9 , lesser amounts (25–30%) of 10 and substantial amounts (42–55%) of 2‐[4‐(Ar′O)‐ArS]‐2′‐(Ar′O)diphenyl sulfide ( 12 ). Small amounts of 1,4‐di(Ar′O)benzene ( 11 ) were also obtained from reactions of 1d and e . Formation of 11 and 12 is preceded by replacement of halogen by Ar′O − . Structures of products 10 and 12 were deduced by comparison with earlier products from thiolate reactions, elemental analyses, mass spectrometry molecular masses and, in the case of 10 , the crystal structure of 10d . It is proposed that products 9 – 12 are formed by nucleophilic reactions of Ar′O − at ipso positions in 1 . Copyright © 2003 John Wiley & Sons, Ltd.