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A ligand-free, highly efficient Cu-catalytic N-arylation of iminodibenzyl and iminostilbene derivatives with a broad scope of unactivated aryl halides under mild conditions has been developed for the first time. Moreover, the first Ni-based catalytic system was also applied to the N-arylation of pre-existing derivatives. These novel protocols provide facile and convenient access to the construction of dibenzazepines and offer promising alternatives to the widely used palladium catalysts.

Efficient procedures for the synthesis of benzo-fluorinated dibenz[b,f]azepines (iminostilbenes) from fluorinated isatins or indoles using a number of ring-expansion reactions are described. A range of mono- and difluorinated analogues is accessible, and the syntheses can deliver gram quantities of the final products, which are precursors of fluoro analogues of the important anticonvulsant carbamazepine.

Almost one hundred imipramine analogues, mainly iminodibenzyls, iminostilbenes, and phenothiazines, were screened for central antidepressant activity. The test was based on the characteristic behavioral syndrome (spontaneous excitation) produced in rats by treatment with a desmethylimipramine-type drug and Ro 4-1284, a benzoquinolizine that rapidly releases brain catecholamtnes. In addition to desmethylimipramine and desmethylamitriptyline, the test has disclosed seventeen other potential antidepressants, including two phenothiazines which also possessed tranquilizing properties. From the results, certain relationships between structure and antidepressant activity are discernible and may be described in terms of the essential parts of the ring system, the length of the sidechain, and the nature and position of substituent groups. The majority of the active compounds are secondary methylamines and a few are primary amines. In general, the tertiary amines do not act as antidepressants and in many instances act as sedatives. In fact, sedative agents are sometimes converted to antidepressants by N-demethylation. Some implications of these findings are discussed.

Reactions of carbazoles and 10,11-dihydro-5H-dibenz[b,f]azepines with 2,3-dichloro-5,6-dicyano-p-benzoquinone in the presence of acids, and with tris-(p-bromophenyl)ammoniumyl salts gave good yields of cation radical salts from ring coupled dimers. Corresponding reactions with iminostilbenes gave mixtures of dimers which could not be separated.