Department of Molecular Probes, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555, Japan.
Bioorg Med Chem Lett. 2009 Nov 1;19(21):6222-4. doi: 10.1016/j.bmcl.2009.08.097. Epub 2009 Sep 3.
The synthesis of (R,S)-[4-11C]baclofen, the first 11C-labeled GABAB agonist, was demonstrated via Michael addition of nitro[11C]methane as a key step. A tetrabutylammonium fluoride promoted Michael addition of nitro[11C]methane to methyl p-chlorocinnamate, followed by the nitro-group reduction in the presence of NiCl2 and NaBH4 in aqueous MeOH and alkaline hydrolysis yielded (R,S)-[4-11C]baclofen in 36.4+/-1.8% radiochemical conversion in three steps within 20 min.
（R，S）-[4-11C]巴氯芬的合成，首个 11C 标记的 GABAB 激动剂，通过迈克尔加成反应的硝基[11C]甲烷作为关键步骤得到了证明。四丁基氟化铵促进硝基[11C]甲烷与对氯肉桂酸甲酯的迈克尔加成，然后在 NiCl2 和 NaBH4 的存在下进行硝基还原，在含水 MeOH 中，再经过碱性水解，在 3 步反应 20 分钟内得到（R，S）-[4-11C]巴氯芬，放射化学转化率为 36.4+/-1.8%。
