Convenient synthesis, characterization and GPx-like catalytic activity of novel ebselen derivatives

The synthesis and characterization of benzisochalcogenazolones (ebselen derivatives 16-21) is described. The synthesis of 16-21 was achieved by treating the bromo precursors 11-13 with an appropriate dilithium dichalcogenide. The synthesis of benzisoselenazolones 16 and 18 was also accomplished by an alternative route, that is, by treating the corresponding methoxymethyl selenides 22 and 23 with 1 equiv. of bromine. The synthesis of methoxymethyl selenides 22 and 23 was accomplished by lithiation of the bromo precursors followed by treatment with bis(methoxymethyl) diselenide. The benzisoselenazolones 16 and 17 were characterized by single-crystal X-ray techniques. The GPx-like catalytic activities of compounds 16-18 and 21 were determined by using the coupled reductase assay. Compound 16 was found to be less active than ebselen 8 whereas compounds 17 and 18 were more active than ebselen in this assay. Compound 21 showed a 1.5-fold higher activity than its selenium analogue 17. ((C) Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004).