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

Abstract

AbstractReactions 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.