Synthesis of [N-methyl-11C]-3-[(6-dimethylamino)pyridin-3-yl]-2,5-dimethyl-N, N-dipropylpyrazolo[1,5-a]pyrimidine-7-amine: A potential PET ligand forin vivo imaging of CRF1 receptors
作者:J.S. Dileep Kumar、Vattoly J. Majo、Jaya Prabhakaran、Norman R. Simpson、Ronald L. Van Heertum、J. John Mann
DOI:10.1002/jlcr.738
日期:2003.10.15
using conventional bases were not successful. However, the radiolabeling of [11C]R121920 was successfully carried out with [11C]MeOTf in acetone at −20°C in the absence of added basic reagents. The radiotracer was purified by RP-HPLC followed by RP-solid phase extraction. The yield of the reaction was 5% (at EOB) and the specific activity was >1000 Ci/mmol (at EOB) with a radiochemical purity >99%. Copyright
[N-甲基-11C]-3-[(6-二甲氨基)吡啶-3-基]-2,5-二甲基-N,N-二丙基吡唑并[1,5-a]嘧啶-7-胺的便捷合成(R121920),一种高选择性 CRF1 拮抗剂已被开发为潜在的 PET 配体。3 - [(6 - 甲氨基)吡啶 - 3 - 基]-2,5-二甲基-N,N-二丙基吡唑并[1,5-a]嘧啶-7-胺 (7),用于放射性标记的前体是通过新型钯催化芳基溴 5 与杂芳基硼酸酯 4 的 Suzuki 偶联。所需的硼酸酯 4 由 2-氨基-4-溴吡啶分四步合成,总产率为 50%。尽管冷 R121920 的合成以 93% 的产率通过六甲基二硅叠氮化钠 (NaHMDS) 介导的去甲胺 7 在 -78°C 下进行 N-甲基化,但尝试在各种条件下使用常规碱进行放射合成并没有成功。然而,在不添加碱性试剂的情况下,在-20°C 的丙酮中使用 [11C]MeOTf 成功地对 [11C]R121920