A facile method for the preparation of conformationally rigid analogues of the adrenergic α-2 receptor antagonist atipamezole and the adrenergic α-2 receptor agonist medetomidine has been developed. The efficient benzyne [4+2] cycloaddition reaction was used to give the core 7-acetylbenzonorbornadiene structure, which was subsequently elaborated to the corresponding imidazole-based syn and anti isomers by means of the classical Bredereck’s method.
Yli-Kauhaluoma, J., Laine, A., Ratilainen, J., & Karjalainen, A. (2005). Synthesis of benzobicyclo[2.2.1]heptylimidazoles as conformationally constrained adrenergic receptor antagonists. Heterocycles, 65(11), 2783-2790. https://doi.org/10.3987/COM-05-10535