1,9-Alkano-bridged 2,3,4,5-tetrahydro-1H-3-benzazepines with affinity for the alpha 2-adrenoceptor and the 5-HT1A receptor

J Med Chem. 1990 Feb;33(2):633-41. doi: 10.1021/jm00164a026.

Abstract

A number of 1,9-alkano-bridged 2,3,4,5-tetrahydro-1H-3-benzazepines were prepared and evaluated for 5-HT1A receptor and alpha 2-adrenoceptor affinity by using radioligand receptor binding techniques. Several compounds displayed 5-HT1A receptor affinity comparable to, or greater than, the known 5-HT1A ligand buspirone. The highest affinity 5-HT1A receptor ligands were N-alkyl-, N-allyl-5-chloro-, and 5-methoxy-1,2,3,4,8,9,10,10a-octahydronaphth[1,8-cd]azapines (4c, 4m, 4n), which had pKi values of 7.9-8.1. The S enantiomer of 4c had a higher affinity for the 5-HT1A receptor than the corresponding R isomer (pKi of 8.2 for (S)-4c vs 7.7 for (R)-4c). These compounds had a relatively low affinity for the alpha 2-adrenoceptor (pKi of 7 or less). On the other hand, the closely related 5-chloro-2-methyl-2,3,4,8,9,9a-hexahydro-1H-indeno[1,7-cd]azepine (3b) had high affinity for both the alpha 2-adrenoceptor (pKi = 8.1) and 5-HT1A receptor (pKi = 7.6). These results indicate that the two receptors may share common recognition sites.

MeSH terms

  • Animals
  • Benzazepines / chemical synthesis*
  • Benzazepines / metabolism
  • Cerebral Cortex / metabolism
  • Chemical Phenomena
  • Chemistry
  • Chemistry, Physical
  • In Vitro Techniques
  • Radioligand Assay
  • Rats
  • Rats, Inbred Strains
  • Receptors, Adrenergic, alpha / metabolism*
  • Receptors, Serotonin / metabolism*
  • Structure-Activity Relationship
  • Thermodynamics

Substances

  • Benzazepines
  • Receptors, Adrenergic, alpha
  • Receptors, Serotonin