Quinolizidinyl derivatives of 2,3-dihydro-2-oxo-1H-benzimidazole-1-carboxylic acid and 1-homolupinanoyl benzimidazolones as ligands for 5-HT3 and 5-HT4 receptors

Five 2,3-dihydro-2-oxo-1 H-benzimidazole-1 -carboxylic acid derivatives of lupinine, epi-lupinine and lupinylamine, together with two 1-homolupinanoyl benzimidazolones were prepared and investigated for their ability to displ ace specific radioligands from 5-HT3 and 5-HT4 receptors. The synthesized c ompounds were only moderately active, with IC,, in the micromolar range. Th e compound with the highest affinity for 5-HT4 receptor was tested for the enhancement of intestinal transit rate but was inactive at the oral dose of 100 mg/kg. (C) 1999 Elsevier Science S.A. All rights reserved.