title: Efficient Synthesis of Molecular Precursors for Para-Hydrogen-Induced Polarization of Ethyl Acetate-1-(13) C and Beyond.
abstract: A scalable and versatile methodology for production of vinylated carboxylic compounds with (13) C isotopic label in C1 position is described. It allowed synthesis of vinyl acetate-1-(13) C, which is a precursor for preparation of (13) C hyperpolarized ethyl acetate-1-(13) C, which provides a convenient vehicle for potential in vivo delivery of hyperpolarized acetate to probe metabolism in living organisms. Kinetics of vinyl acetate molecular hydrogenation and polarization transfer from para-hydrogen to (13) C via magnetic field cycling were investigated. Nascent proton nuclear spin polarization (%PH ) of ca. 3.3 % and carbon-13 polarization (%P13C ) of ca. 1.8 % were achieved in ethyl acetate utilizing 50 % para-hydrogen corresponding to ca. 50 % polarization transfer efficiency. The use of nearly 100% para-hydrogen and the improvements of %PH of para-hydrogen-nascent protons may enable production of (13) C hyperpolarized contrast agents with %P13C of 20-50 % in seconds using this chemistry.
authors.affiliation: Department of Radiology, Vanderbilt University Institute of Imaging Science (VUIIS), Department of Biomedical Engineering, Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University, Nashville, TN, 37232, USA.
authors.forename: Roman V
authors.initials: RV
authors.lastname: Shchepin
authors.affiliation: Department of Radiology, Vanderbilt University Institute of Imaging Science (VUIIS), Department of Biomedical Engineering, Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University, Nashville, TN, 37232, USA.
authors.forename: Danila A
authors.initials: DA
authors.lastname: Barskiy
authors.affiliation: Department of Radiology, Vanderbilt University Institute of Imaging Science (VUIIS), Department of Biomedical Engineering, Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University, Nashville, TN, 37232, USA.
authors.forename: Aaron M
authors.initials: AM
authors.lastname: Coffey
authors.affiliation: Department of Radiology, Vanderbilt University Institute of Imaging Science (VUIIS), Department of Biomedical Engineering, Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University, Nashville, TN, 37232, USA.
authors.forename: Isaac V
authors.initials: IV
authors.lastname: Manzanera Esteve
authors.affiliation: Department of Radiology, Vanderbilt University Institute of Imaging Science (VUIIS), Department of Biomedical Engineering, Vanderbilt-Ingram Cancer Center (VICC), Vanderbilt University, Nashville, TN, 37232, USA. eduard.chekmenev@vanderbilt.edu.|Russian Academy of Sciences, 119991, Moscow, Russia. eduard.chekmenev@vanderbilt.edu.
authors.forename: Eduard Y
authors.initials: EY
authors.lastname: Chekmenev
mesh_terms: D000085:Acetates / Q000138:chemical synthesis* / Q000737:chemistry; D002247:Carbon Isotopes / Q000737:chemistry; D002384:Catalysis; D056831:Coordination Complexes / Q000737:chemistry; D006859:Hydrogen / Q000737:chemistry*; D007553:Isotope Labeling; D009682:Magnetic Resonance Spectroscopy; D012238:Rhodium / Q000737:chemistry
chemical_list: D000085:Acetates; D002247:Carbon Isotopes; D056831:Coordination Complexes; C007650:ethyl acetate; D006859:Hydrogen; D012238:Rhodium; C000615229:Carbon-13
keywords: MRI; contrast agents; ethyl acetate; hyperpolarization; para-hydrogen induced polarization (PHIP)