title: Simple synthesis of new carbon-11-labeled 1,2,4-triazolo[4,3-a]quinoxalin-1-one derivatives for PET imaging of A₃ adenosine receptor.
abstract: The reference standards 4a-b, 6a-b, 7a-c, and desmethylated precursors 9a-b, 10a-b, 8a-c were synthesized from 4-methoxyaniline, ethyl 2-chloro-acetoacetate and substituted benzene-1,2-diamines with 3, 5, 6 steps in 61-67%, 34-41%, 23-31%, and with 4, 6, 7 steps in 49-57%, 28-35%, 20-27% overall chemical yield, respectively. The target tracers [(11)C]4a-b, [(11)C]6a-b, [(11)C]7a-c were synthesized from their corresponding precursors with [(11)C]CH3OTf through O-[(11)C]methylation and isolated by simplified SPE in 40-60% decay corrected radiochemical yields at EOB, with 185-370 GBq/μmol specific activity at EOS.
authors.affiliation: Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, L3-202, Indianapolis, IN 46202, USA.
authors.forename: Mingzhang
authors.initials: M
authors.lastname: Gao
authors.affiliation: Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, L3-202, Indianapolis, IN 46202, USA.
authors.forename: Andy Chufan
authors.initials: AC
authors.lastname: Gao
authors.affiliation: Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, L3-202, Indianapolis, IN 46202, USA.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.affiliation: Department of Radiology and Imaging Sciences, Indiana University School of Medicine, 1345 West 16th Street, L3-202, Indianapolis, IN 46202, USA. Electronic address: qzheng@iupui.edu.
authors.forename: Qi-Huang
authors.initials: QH
authors.lastname: Zheng
mesh_terms: D002250:Carbon Radioisotopes / Q000737:chemistry*; D007553:Isotope Labeling / Q000379:methods; D009682:Magnetic Resonance Spectroscopy; D049268:Positron-Emission Tomography / Q000379:methods; D011810:Quinoxalines / Q000138:chemical synthesis* / Q000737:chemistry; D019275:Radiopharmaceuticals / Q000138:chemical synthesis* / Q000737:chemistry; D043684:Receptor, Adenosine A3 / Q000032:analysis*; D021241:Spectrometry, Mass, Electrospray Ionization; D014230:Triazoles / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: C469661:1,2,4-triazolo(4,3-a)quinoxaline; D002250:Carbon Radioisotopes; D011810:Quinoxalines; D019275:Radiopharmaceuticals; D043684:Receptor, Adenosine A3; D014230:Triazoles
keywords: A(3) adenosine receptor; Cancer; Carbon-11-labeled 1,2,4-triazolo[4,3,a]quinoxalin-1-one derivatives; Cardiac diseases; Neurological disorders; Positron emission tomography (PET)