Download PDF Opens in a new window. Article suggestions will be shown in a dialog on return to ScienceDirect. ... Please enable JavaScript to use all the features on this page. ... 6,11-Dihydrobenzo[b]pyrrolo[4,3,2-de][1,10]phenanthroline-5,8-dione (6), which possesses a unique heterocyclic ring system similar to that in plakinidines A–D (1–4), was synthesized from 2-acetyl-3′-nitrodiphenylamine (16) in nine steps. ... 6,11-Dihydrobenzo[b]pyrrolo[4,3,2- ...