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Updated: Sep 5, 2025

Preparation of Stable Bicyclic Aziridinium Ions and Their Ring-Opening for the Synthesis of Azaheterocycles
Published on: August 22, 2018
A new approach to 10-arylated 5H-dibenzo[b,f]azepines using syn-selective hydrohalogenation of ethynylaniline
Kento Iwai1,2, Yusuke Mukaijo1, Haruyasu Asahara1,2,3
1School of Environmental Science and Engineering, Kochi University of Technology, Tosayamada, Kami, Kochi 782-8502, Japan. nishiwaki.nagatoshi@kochi-tech.ac.jp.
Abstract:
A new synthetic method for 10-arylated dibenzo[b,f]azepines was developed. The pseudo-intramolecular hydrohalogenation of 2-(2'-bromophenyl)ethynylaniline, which proceeded in a syn-selective manner without forming any detectable over-addition product, was a crucial step. All attempts of subsequent arylation via Suzuki-Miyaura cross coupling and construction of a seven membered ring via Ullmann-type intramolecular coupling were unsuccessful because of dehydrohalogenation or other side reactions. This problem was overcome by the N-acetylation of the amino group, which facilitated the abovementioned coupling reactions to afford the desired 10-arylated dibenzoazepines.
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