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-1H-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 displace specific radioligands from 5-HT3 and 5-HT4 receptors. The synthesized compounds were only moderately active, with IC50 in the micromolar range. The 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.