TETRAZINODIHETARENES - SYNTHESIS AND PROP ERTIES OF NEW MULTISTEP WEITZ-TYPE REDOX SYSTEMS

The s-tetrazine derivatives 3a-d and 6 were obtained by electrophilic amination of N-heterocycles bearing a leaving group in alpha-position and subsequent condensation under basic conditions, The corresponding N-amino salts 2a-f, 5 and 7 could be isolated and characterised. Under the same conditions, it was not possible to obtain a corresponding te trazine from 5 but the mesoionic hetarylium-N-imide 6 could be isolate d. The structure of 11 was supported by X-ray structure determination of its hydrogen sulfate salt. The redox potentials of the new compound s were determined by cyclovoltammetric methods. The tetrazines easily form radical salts which show unusually high stability.