6,7,14,15-Tetrahydro[1,5]diazocino[1,2-a:6,5-a′]diindole. Synthesis of a novel pentacyclic ring system

In search of new lead structures for potent allosteric enhancers of antagonist binding to muscarinic M2 receptors, the first representative of a novel heterocyclic ring system, 6,7,14,15-tetrahydro[1,5]diazocino[1,2-a:6,5-a′]diindole, has been synthesized. The new pentacyclic ring skeleton is obtained from [3-(2-dibenzylaminoethyl)indol-2-yl]-acetic acid methyl ester in three steps.