Browsing by Author "Jia, Limeng"

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    Facile synthesis of carbon-11-labeled sEH/PDE4 dual inhibitors as new potential PET agents for imaging of sEH/PDE4 enzymes in neuroinflammation
    (Elsevier, 2019-07) Jia, Limeng; Miao, Caihong; Dong, Fugui; Li, Wei; Wang, Min; Zheng, Qi-Huang; Xu, Zhidong; Radiology and Imaging Sciences, School of Medicine
    To develop PET tracers for imaging of neuroinflammation, new carbon-11-labeled sEH/PDE4 dual inhibitors have been synthesized. The reference standard N-(4-methoxy-2-(trifluoromethyl)benzyl)benzamide (1) and its corresponding desmethylated precursor N-(4-hydroxy-2-(trifluoromethyl)benzyl)benzamide (2) were synthesized from (4-methoxy-2-(trifluoromethyl)phenyl)methanamine and benzoic acid in one and two steps with 84% and 49% overall chemical yield, respectively. The standard N-(4-methoxy-2-(trifluoromethyl)benzyl)-1-propionylpiperidine-4-carboxamide (MPPA, 4) and its precursor N-(4-hydroxy-2-(trifluoromethyl)benzyl)-1-propionylpiperidine-4-carboxamide (5) were synthesized from methyl 4-piperidinecarboxylate, propionyl chloride and (4-methoxy-2-(trifluoromethyl)phenyl)methanamine in two and three steps with 62% and 34% overall chemical yield, respectively. The target tracers N-(4-[11C]methoxy-2-(trifluoromethyl)benzyl)benzamide ([11C]1) and N-(4-[11C]methoxy-2-(trifluoromethyl)benzyl)-1-propionylpiperidine-4-carboxamide ([11C]MPPA, [11C]4) were prepared from their corresponding precursors 2 and 5 with [11C]CH3OTf through O-[11C]methylation and isolated by HPLC combined with SPE in 25–35% radiochemical yield, based on [11C]CO2 and decay corrected to end of bombardment (EOB). The radiochemical purity was >99%, and the molar activity (AM) at EOB was 370–740 GBq/μmol with a total synthesis time of 35–40-minutes from EOB.
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    Radiosynthesis of a carbon-11 labeled tetrahydrobenzisoxazole derivative as a new PET probe for γ-secretase imaging in Alzheimer's disease
    (Elsevier, 2020-01) Xu, Zhidong; Miao, Caihong; Dong, Fugui; Jia, Limeng; Li, Wei; Wang, Min; Liu, Wenqing; Zheng, Qi-Huang; Radiology and Imaging Sciences, School of Medicine
    To develop PET radiotracers for imaging of Alzheimer's disease, a new carbon-11 labeled potent and selective γ-secretase modulator (GSM) has been synthesized. The reference standard tetrahydrobenzisoxazole derivative 8 and its desmethylated precursor 9 were synthesized from cyclohex-2-en-1-one and 3-hydroxy-4-nitrobenzaldehyde in eight and nine steps with 11% and 5% overall chemical yield, respectively. The radiotracer [11C]8 was prepared from its corresponding precursor 9 with [11C]CH3OTf through O–11C-methylation and isolated by RP-HPLC combined with SPE in 45–50% radiochemical yield, based on [11C]CO2 and decay corrected to EOB. The radiochemical purity was >99%, and the molar activity (Am) at EOB was 555–740 GBq/μmol.
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    Radiosynthesis of a carbon-11-labeled AMPAR allosteric modulator as a new PET radioligand candidate for imaging of Alzheimer’s disease
    (Elsevier, 2019-05) Miao, Caihong; Dong, Fugui; Jia, Limeng; Li, Wei; Wang, Min; Zheng, Qi-Huang; Xu, Zhidong; Radiology and Imaging Sciences, School of Medicine
    To develop PET tracers for imaging of Alzheimer’s disease, a new carbon-11-labeled AMPAR allosteric modulator 4-cyclopropyl-7-(3-[11C]methoxyphenoxy)-3,4-dihydro-2H-benzo[e][1,2,4]thiadiazine 1,1-dioxide ([11C]8) has been synthesized. The reference standard 4-cyclopropyl-7-(3-methoxyphenoxy)-3,4-dihydro-2H-benzo[e][1,2,4]thiadiazine 1,1-dioxide (8) and its corresponding desmethylated precursor 4-cyclopropyl-7-(3-hydroxyphenoxy)-3,4-dihydro-2H-benzo[e][1,2,4]thiadiazine 1,1-dioxide (9) were synthesized from 4-methoxyabiline and chlorosulfonyl isocyanate in eight and nine steps with 3% and 1% overall chemical yield, respectively. The target tracer [11C]8 was prepared from the precursor 9 with [11C]CH3OTf through O-[11C]methylation and isolated by HPLC combined with SPE in 10–15% radiochemical yield, based on [11C]CO2 and decay corrected to end of bombardment (EOB). The radiochemical purity was >99%, and the molar activity (AM) at EOB was 370–740 GBq/μmol with a total synthesis time of 35–40-minutes from EOB.
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    Radiosynthesis of carbon-11 labeled PDE5 inhibitors as new potential PET radiotracers for imaging of Alzheimer's disease
    (Elsevier, 2019-12) Dong, Fugui; Du, Jie; Miao, Caihong; Jia, Limeng; Li, Wei; Wang, Min; Zheng, Qi-Huang; Xu, Zhidong; Radiology and Imaging Sciences, School of Medicine
    To develop PET tracers for imaging of Alzheimer's disease, new carbon-11 labeled potent and selective PDE5 inhibitors have been synthesized. The reference standards (5) and (12), and their corresponding desmethylated precursors (6) and (13) were synthesized from methyl 2-amino-5-bromobenzoate and (4-methoxyphenyl)methanamine in multiple steps with 2%, 1%, 1% and 0.2% overall chemical yield, respectively. The radiotracers ([11C]5) and ([11C]12) were prepared from their corresponding precursors 6 and 13 with [11C]CH3OTf through O–11C-methylation and isolated by HPLC combined with SPE in 40–50% radiochemical yield, based on [11C]CO2 and decay corrected to EOB. The radiochemical purity was >99%, and the molar activity (Am) at EOB was in a range of 370–740 GBq/μmol.