The dibenzoazepine is the structural motif of several drugs such as analgesics and antipsychotics, and its derivatives with various pharmacological properties have been synthesized. Dibenzoazepine has a non-planar structure when an acyl group is substituted on the nitrogen, and the butterfly motion of the 7-membered ring due to this non-planar structure and the C-N rotation of the amide result in multiple isomers of the same molecule. The isomerization behavior of these isomers and their effects on the biological activity are of great interest.
In this study, we synthesized a new compound of this N-acyl dibenzoazepine derivative fused with a cyclobutane ring at the double bond site and investigated its butterfly motion and C-N rotation behavior. As a result, we isolated several isomers, evaluated their thermodynamic stability, and clarified their isomerization behavior. In the future, we will study the biological activity of these isomers.