Chemical modification of apomorphine to discover σ ligands: 6H-dibenzo[b,d]pyran and carbazole analogues Original Research Article

It seems that many σ ligands have been designed from known sigma ligands. We focused on a difference in structural flexibility between haloperidol and apomorphine, and studied chemical modification of apomorphine, a compound with high affinity for dopamine D2 receptors but not for σ receptors, for discovery of σ ligands. The first modification yielded good results with 6H-dibenzo[b,d]pyran analogues with weak affinity for σ receptors but not D2 receptors. Furthermore, carbazole analogues, compounds designed from 6H-dibenzo[b,d]pyran analogues, potentially acted at σ receptors with high selectivity. This paper describes the design, synthesis and sigma/D2 selectivity of 6H-dibenzo[b,d]pyran and carbazole analogues.