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Synthesis of a11C-labeledD-amino acid oxidase inhibitor for PET imaging
https://repo.qst.go.jp/records/80198
https://repo.qst.go.jp/records/801985b647da4-9791-4b95-8959-35ea8513c07e
| Item type | 会議発表用資料 / Presentation(1) | |||||
|---|---|---|---|---|---|---|
| 公開日 | 2020-07-08 | |||||
| タイトル | ||||||
| タイトル | Synthesis of a11C-labeledD-amino acid oxidase inhibitor for PET imaging | |||||
| 言語 | ||||||
| 言語 | eng | |||||
| 資源タイプ | ||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_c94f | |||||
| 資源タイプ | conference object | |||||
| アクセス権 | ||||||
| アクセス権 | metadata only access | |||||
| アクセス権URI | http://purl.org/coar/access_right/c_14cb | |||||
| 著者 |
Deng, Xiaoyun
× Deng, Xiaoyun× Shao, Tuo× Shao, Yihan× Josephson, Lee× Hsiao-Ying, Wey× Ming-Rong, Zhang× Liang, Huan× Ming-Rong, Zhang× Liang, Huan |
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| 抄録 | ||||||
| 内容記述タイプ | Abstract | |||||
| 内容記述 | Objectives: We have identified 4-hydroxy-6-(3-methoxyphenethyl)pyridazin-3(2H)-one (1) as a lead molecule for D-amino acid oxidase (DAAO)-specific PET ligand. It has been reported that inhibitory activity of compound 1 for human, mouse and rat DAAOs showed dose-dependent responses with IC50 valves of 8.8, 4.4 and 5.6 nM, respectively. [1] The goal of the project was to synthesize the standard and precursor molecules for this target and perform radiolabeling of compound 1 with carbon-11. Methods: The leading compound 1 was synthesized in the following procedures. The cyclization of 3,4,6-trichloropyridazine 2 and pyrocatechol 3 led to intermediate 4 in 80% yield. Through the Sonagashira coupling reaction of compound 4 and 1-ethynyl-3-methoxybenzene 5, the alkyne 6 was obtained in 40% yield. Exchanged with phenylmethanol under base, compound 6 was converted to benzyl-protected ether 7 in 58% yield. After Pd-mediated hydrogenation of compound 7, the desired product 1 was obtained in 77% yield (Scheme 1A). The synthesis of the labeling precursor for compound 1 was showed in Scheme 1B. Phenylmethanol was used to react with compound 4 to get benzyl-protected ether 8 in 48% yield. After hydrogenation of compound 8 under hydrogen using palladium/carbon catalysis, 6-chloro-4-hydroxypyridazin-3(2H)-one 9 was obtained in 84% yield. Hydroxy groups were then protected by the treatment with chloromethyl methyl ether to give compound 10 in 40% yield, followed by the Sonagashira coupling reaction with alkyne 12 to produce compound 13 in 38% yield. At the end, benzyl protecting group was removed by palladium hydroxide/carbon catalysis under hydrogen to yield the precursor 14 in 71% yield. Preliminary 11C-labeling was carried out using precursor (14; 1.6 mg) with [11C]methyl iodide in the presence of Cs2CO3 in DMF (0.4 mL) at 80°C for 5 min to generate [11C]15 (Scheme 1C). Then, 4 M HCl in dioxane was added to remove the MOM group and the mixture was neutralized with NaHCO3 aqueous solution to get [11C]1. Results: The synthesis of candidate compound 1 was obtained from commercially available 3,4,6-trichloropyridazine 2 and pyrocatechol 3 in four steps with overall yield of 14%. The radioligand [11C]1 was synthesized in 13 ± 3% radiochemical yield based on [11C]CH3I (decay corrected). The tracer was obtained at end-of-synthesis (70 min synthesis time) with high radiochemical purity (>99%) and molar activity (> 1.0 Ci/μmol; 37 GBq/μmol). No radiolysis was observed within 90 min. Conclusions: We have successfully prepared one potent and selective DAAO ligand and performed 11C-labeling with a reasonable radiochemical yield and high molar activity. Preliminary in vivo evaluation by PET are underway. References: [1] T. Hondo, M. Warizaya, T. Niimi, I. Namatame, T. Yamaguchi, K. Nakanishi, T. Hamajima, K. Harada, H. Sakashita, Y. Matsumoto, J. Med. Chem. 2013, 56, 3582. |
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| 会議概要（会議名, 開催地, 会期, 主催者等） | ||||||
| 内容記述タイプ | Other | |||||
| 内容記述 | SNMMI 2020 Annual Meeting | |||||
| 発表年月日 | ||||||
| 日付 | 2020-07-12 | |||||
| 日付タイプ | Issued | |||||
