Indolo benzazepinone

Construction of the indole ring via Fischer synthesis. Starting from a variety of 3,4-dihydro-lH-benzo[l ]azepine-2,5-diones 40 and arylhydrazines Fischer syntheses of indolo benzazepinones 41 have been reported (Scheme 8 (1999JMC2909)). Usually, the reaction comprises a two-step one-pot procedure with the formation of intermediate arylhydrazones in warm acetic acid followed... 

Reaction of indolo benzazepinone 27 with phosphorus pentasulfide yields 91% of the corresponding thione 415 (Scheme 87 (1993LA1141)). 

A second approach to the indolo[3,2-c /]benzazepinone system was also reported in 2005 by Joseph and coworkers. This involved a neat route based on 3-substituted indole derivatives and an intramolecular Heck coupling to form the 12a-12b bond in the fused ring system <05TL8177>. 

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