Browsing by Author "Xu, Wenzhi"

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    Synthesis of N-(3-(4-[11C]methylpiperazin-1-yl)−1-(5-methylpyridin-2-yl)−1H-pyrazol-5-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide as a new potential PET agent for imaging of IRAK4 enzyme in neuroinflammation
    (Elsevier, 2018-02) Wang, Xiaohong; Xu, Wenzhi; Miao, Caihong; Dong, Fugui; Li, Wei; Wang, Min; Gao, Mingzhang; Zheng, Qi-Huang; Xu, Zhidong; Radiology and Imaging Sciences, School of Medicine
    The reference standard N-(3-(4-methylpiperazin-1-yl)−1-(5-methylpyridin-2-yl)−1H-pyrazol-5-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide (9) and its demethylated precursor N-(1-(5-methylpyridin-2-yl)−3-(piperazin-1-yl)−1H-pyrazol-5-yl)pyrazolo[1,5-α]pyrimidine-3-carboxamide (8) were synthesized from pyrazolo[1,5-a]pyrimidine-3-carboxylic acid and ethyl 2-cyanoacetate with overall chemical yield 13% in nine steps and 14% in eight steps, respectively. The target tracer N-(3-(4-[11C]methylpiperazin-1-yl)−1-(5-methylpyridin-2-yl)−1H-pyrazol-5-yl)pyrazolo[1,5-a]pyrimidine-3-carboxamide ([11C]9) was prepared from its precursor with [11C]CH3OTf through N-[11C]methylation and isolated by HPLC combined with SPE in 50–60% radiochemical yield, based on [11C]CO2 and decay corrected to EOB. The radiochemical purity was >99%, and the specific activity at EOB was 370–1110 GBq/μmol.