title: Design, synthesis and in vitro evaluation of bridgehead fluoromethyl analogs of N-{2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl}-N-(pyridin-2-yl)cyclohexanecarboxamide (WAY-100635) for the 5-HT(1A) receptor.
abstract: Fluorinated analogs that are related to the 5-hydroxytryptamine (5-HT(1A)) antagonist, N-{2-[4-(2-methoxyphenyl)piperazin-1-yl]ethyl}-N-(pyridin-2-yl)cyclohexanecarboxamide (WAY-100635), have been synthesized and their binding affinity for the 5-HT(1A) receptor and other neurotransmitter receptors (adrenoceptors, sigma receptors, and dopamine receptors), and serotonin transporters was examined in vitro. These ligands were designed to provide a possible potential positron emission tomography (PET) ligand with high metabolic stability. To this end, the cyclohexyl moiety in WAY-100635 and in O-desmethyl WAY-100635 was replaced by a bridge-fused ring (BFR) such as adamantyl, cubyl, bicyclo[2.2.2]octyl and bicyclo[2.2.1]heptyl to reduce the metabolic rate of the amide bond hydrolysis, while a fluoromethyl group was introduced on the other bridgehead of the BFR to prevent defluorination by HF elimination. All synthesized analogs displayed high affinity in the (sub)nanomolar range for the 5-HT(1A) receptor, comparable to WAY-100635. In addition, 6b, 6c and 6d were reasonably selective to the 5-HT(1A) receptor over the above mentioned receptors. In human hepatocytes, 6b showed a suitable metabolic stability. In conclusion, the obtained data provides a promising starting point for the synthesis of the corresponding (18)F-labeled PET analogs.
authors: Department of Nuclear Medicine & PET Research, VU University Medical Center, PO Box 7057, 1007MB Amsterdam, The Netherlands. rhussainy@rnc.vu.nl
authors: Rana
authors: R
authors: Al Hussainy
authors: Joost
authors: J
authors: Verbeek
authors: Dion
authors: D
authors: van der Born
authors: Jan
authors: J
authors: Booij
authors: J Koos D M
authors: JK
authors: Herscheid
mesh_terms: D002460:Cell Line; D015195:Drug Design; D054879:Halogenation; D006801:Humans; D010879:Piperazines / Q000737:chemistry* / Q000494:pharmacology*; D049268:Positron-Emission Tomography; D011485:Protein Binding; D011725:Pyridines / Q000737:chemistry* / Q000494:pharmacology*; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D058829:Serotonin 5-HT1 Receptor Antagonists / Q000737:chemistry* / Q000494:pharmacology*
chemical_list: D010879:Piperazines; D011725:Pyridines; D058829:Serotonin 5-HT1 Receptor Antagonists; D044282:Receptor, Serotonin, 5-HT1A; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide