Synthesis of Tetracyclic 2,3-Dihydro-1,3-diazepines from a Dinitrodibenzothiophene Derivative

Triply fused 1,3-diazepine
derivatives have been obtained by acidic
reduction of rotationally locked and sterically hindered nitro groups
in the presence of an aldehyde or ketone. The nitro groups are sited
on adjacent rings of a dicyanodibenzothiophene-5,5-dioxide, which
also displays fully reversible two-electron-accepting behavior. The
synthesis, crystallographically determined molecular structures, and
aspects of the electronic properties of these new molecules are presented.