The synthesis and enzyme inhibitor properties of reversible type B monoamine oxidase inhibitors are described. These compounds belong to the 5H-indeno[ 1,2-c] pyridazine family and possess a hydrophobic benzyloxy or 4,4,4-trifluorobutoxy side chain which, in contrast to a previous assignment, has been unambiguously located at C( 8) of the heterocyclic moiety. Investigation of the regioisomeric structures establishes that substitution of the 5H-indeno[ 1,2-c] pyridazin-5-one core at C( 7) vs C( 8) dramatically influences the MAO-inhibiting properties of these compounds.
Frédérick, R., Dumont, W., Ooms, F., Aschenbach, L., van der Schyf, C. J., Castagnoli, N., Wouters, J., & Krief, A. (2006). Synthesis, structural reassignment, and biological activity of type B MAO inhibitors based on the 5H-indeno[1,2-c]pyridazin-5-one core. Journal of Medicinal Chemistry, 49(12), 3743-3747. https://doi.org/10.1021/jm051091j (Original work published 2006)