Synthesis and evaluation of halogenated dibenzodiazepines as muscarinic receptor ligands

Syntheses of four novel amide analogues of the muscarinic M2 receptors antagonists, DIBA and BIBN 140, are described from a common intermediate. Pharmacological evaluation through in vitro assays reveals high muscarinic receptor affinity in each of the compounds, but variable subtype selectivity, primarily M2 but in one case M3.