ArticleBioorganic & medicinal chemistry letters2013
Radiosynthesis and evaluation of [11C]EMPA as a potential PET tracer for orexin 2 receptors.
Article in Bioorganic & medicinal chemistry letters, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers.
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10 citing papers in PubMed, 29 citations in OpenAlex.
- Development of NovelACS pharmacology & translational science · 2025Article
- Heteroaryl derivatives of suvorexant as OX1R selective PET ligand candidates: Cu-mediatedEJNMMI research · 2024Article
- Synthesis and Characterization of a New Carbon-11 Labeled Positron Emission Tomography Radiotracer for Orexin 2 Receptors Neuroimaging.Drug design, development and therapy · 2024Article
- Development of NovelACS medicinal chemistry letters · 2023Article
- Synthesis and characterization of a new Positron emission tomography probe for orexin 2 receptors neuroimaging.Bioorganic chemistry · 2022Article
- Positron Emission Tomography in the Neuroimaging of Autism Spectrum Disorder: A Review.Frontiers in neuroscience · 2022Review
- A New Positron Emission Tomography Probe for Orexin Receptors Neuroimaging.Molecules (Basel, Switzerland) · 2020Article
- Synthesis and characterization of a novelMedChemComm · 2019Article
- Failed PET Application Attempts in the Past, Can We Avoid Them in the Future?Molecular imaging and biology · 2016Article
- A potent and selective C-11 labeled PET tracer for imaging sphingosine-1-phosphate receptor 2 in the CNS demonstrates sexually dimorphic expression.Organic & biomolecular chemistry · 2015Article
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Authors and funding
6 authors at 3 institutions in 1 country.
Funding
Abstract
EMPA is a selective antagonist of orexin 2 (OX2) receptors. Previous literature with [(3)H]-EMPA suggest that it may be used as an imaging agent for OX2 receptors; however, brain penetration is known to be modest. To evaluate the potential of EMPA as a PET radiotracer in non-human primate (as a step to imaging in man), we radiolabeled EMPA with carbon-11. Radiosynthesis of [(11)C]N-ethyl-2-(N-(6-methoxypyridin-3-yl)-2-methylphenylsulfonamido)-N-(pyridin-3-ylmethyl)acetamide ([(11)C]EMPA), and evaluation as a potential PET tracer for OX2 receptors is described. Synthesis of an appropriate non-radioactive O-desmethyl precursor was achieved from EMPA with sodium iodide and chlorotrimethylsilane. Selective O-methylation using [(11)C]CH3I in the presence of cesium carbonate in DMSO at room temp afforded [(11)C]EMPA in 1.5-2.5% yield (non-decay corrected relative to trapped [(11)C]CH3I at EOS) with ≥95% chemical and radiochemical purities. The total synthesis time was 34-36min from EOB. Studies in rodent suggested that uptake in tissue was dominated by nonspecific binding. However, [(11)C]EMPA also showed poor uptake in both rats and baboon as measured with PET imaging.
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