Synthesis of novel 5-substituted 3-amino-3,4-dihydro-2H-1-benzopyran derivatives and their interactions with the 5-HT1A receptor

J Med Chem. 2000 Jul 27;43(15):2837-50. doi: 10.1021/jm990956o.

Abstract

A series of new enantiomerically pure 3-amino-3,4-dihydro-2H-1-benzopyrans (3-aminochromans) has been synthesized from (R)- and (S)-5-methoxy-3-amino-3,4-dihydro-2H-1-benzopyran. The absolute configuration of the respective (R)- and (S)-enantiomers was deduced from X-ray crystallography of (R)-3-(N-isopropylamino)-5-methoxy-3,4-dihydro-2H-1-benzopyran, (R)-9a. Various 5-substituents were introduced via palladium-catalyzed carbonylation of N-substituted 3-amino-5-trifluoromethanesulfonyloxy-3,4-dihydro-2H-1-benzopyran. The effect of N- and 5-substitution on affinity for the 5-HT1A receptor was evaluated in competition experiments using rat hippocampal membranes and [3H]8-OH-DPAT as radioligand. Selected compounds were also tested for their affinity to the D1 (rat striatum), D2 (rat striatum), D2A (human cloned), and 5-HT2A (rat cortex) receptors. The intrinsic activity of the compounds was evaluated by measuring their effect on VIP-stimulated cAMP production in GH4ZD10 cells stably transfected with the 5-HT1A receptor. High-affinity compounds with high selectivity for the 5-HT1A receptor were found among structures substituted with carboxylate esters, amides, and ketones in the 5-position. Primary and secondary amines bound with lower affinity than tertiary amines. Larger substituents were well-tolerated by the receptor, but the smaller N-ethyl-N-isopropyl bound with lower affinity. Generally, the (R)-enantiomers displayed higher affinity for the 5-HT1A receptor than the corresponding (S)-enantiomers. In the present series of compounds, both full and partial agonists were found.

MeSH terms

  • 8-Hydroxy-2-(di-n-propylamino)tetralin / chemistry
  • 8-Hydroxy-2-(di-n-propylamino)tetralin / metabolism
  • Animals
  • Cell Line
  • Cerebral Cortex / metabolism
  • Corpus Striatum / metabolism
  • Crystallography, X-Ray
  • Cyclic AMP / metabolism
  • Hippocampus / metabolism
  • Humans
  • In Vitro Techniques
  • Male
  • Models, Molecular
  • Pyrans / chemical synthesis*
  • Pyrans / chemistry
  • Pyrans / metabolism
  • Radioligand Assay
  • Rats
  • Rats, Sprague-Dawley
  • Receptor, Serotonin, 5-HT2A
  • Receptors, Dopamine D1 / metabolism
  • Receptors, Dopamine D2 / metabolism
  • Receptors, Serotonin / drug effects
  • Receptors, Serotonin / metabolism*
  • Receptors, Serotonin, 5-HT1
  • Serotonin Receptor Agonists / chemical synthesis*
  • Serotonin Receptor Agonists / chemistry
  • Serotonin Receptor Agonists / metabolism
  • Stereoisomerism
  • Structure-Activity Relationship
  • Transfection

Substances

  • Pyrans
  • Receptor, Serotonin, 5-HT2A
  • Receptors, Dopamine D1
  • Receptors, Dopamine D2
  • Receptors, Serotonin
  • Receptors, Serotonin, 5-HT1
  • Serotonin Receptor Agonists
  • 8-Hydroxy-2-(di-n-propylamino)tetralin
  • Cyclic AMP