Design, Synthesis, and Biological Evaluation of 3-Benzazepin-1-ols as NR2B-Selective NMDA Receptor Antagonists
作者:Bastian Tewes、Bastian Frehland、Dirk Schepmann、Kai-Uwe Schmidtke、Thomas Winckler、Bernhard Wünsch
DOI:10.1002/cmdc.201000005
日期:2010.5.3
AbstractCleavage and reconstitution of a bond in the piperidine ring of ifenprodil (1) leads to 7‐methoxy‐2,3,4,5‐tetrahydro‐1H‐3‐benzazepin‐1‐ols, a novel class of NR2B‐selective NMDA receptor antagonists. The secondary amine 7‐methoxy‐2,3,4,5‐tetrahydro‐1H‐3‐benzazepin‐1‐ol (12), which was synthesized in six steps starting from 2‐phenylethylamine 3, represents the central building block for the introduction of several N‐linked residues. A distance of four methylene units between the basic nitrogen atom and the phenyl residue in the side chain results in high NR2B affinity. The 4‐phenylbutyl derivative 13 (WMS‐1405, Ki=5.4 nM) and the conformationally restricted 4‐phenylcyclohexyl derivative 31 (Ki=10 nM) represent the most potent NR2B ligands of this series. Whereas 13 shows excellent selectivity, the 4‐phenylcyclohexyl derivative 31 also interacts with σ1 (Ki=33 nM) and σ2 receptors (Ki=82 nM). In the excitotoxicity assay the phenylbutyl derivative 13 inhibits the glutamate‐induced cytotoxicity with an IC50 value of 360 nM, indicating that 13 is an NMDA antagonist.