A Review of 2,3-Benzodiazepine-related Compounds: Diazepines and 1,2,5-Triazepines Fused with Five-membered Nitrogen Heterocycles

Background: 2,3-Benzodiazepines represent an important class of biologically active compounds, some members of this family have reached the human clinical stage. With formal bioisosteric replacement of the benzene ring to five-membered nitrogen heterocycles, several new diazepine and 1,2,5-triazepine derivatives have been synthesized in the past 30 years. Objective: Investigations in the field of heterocyclic chemistry is very important, because there could be several new medicines among the newly synthesized heterocyclic ring systems, which could be used against several diseases which have no remedy yet, for example some types of cancer. The research on antibacterial compounds is also an important field because of spreading of multiresistant pathogens. This review aims to summarize the literature of certain 2,3-benzodiazepine analogues. Conclusion: After a brief historical introduction, various ring systems containing a 2,3-diazepine or a 1,2,5- triazepine ring condensed with five-membered nitrogen heterocycles are disclosed. First, pyrrole-fused compounds are introduced, followed by indole and carbazole derivatives. After that, diverse ring systems containing an imidazole ring are presented. The review is closed with the chemistry of some interesting triazole and tetrazole derivatives. Many of these compounds bear significant biological efficacy.