Radiosynthesis of a Bruton's tyrosine kinase inhibitor, [
<sup>11</sup>
C]Tolebrutinib, via palladium‐NiXantphos‐mediated carbonylation
作者:Kenneth Dahl、Timothy Turner、Neil Vasdev
DOI:10.1002/jlcr.3872
日期:2020.9
Bruton's tyrosine kinase (BTK) is a key component in the B-cell receptor signaling pathway and is consequently a target for in vivo imaging of B-cell malignancies as well as in multiple sclerosis (MS) with positron emission tomography (PET). A recent Phase 2b study with Sanofi's BTK inhibitor, Tolebrutinib (also known as [a.k.a.] SAR442168, PRN2246, or BTK'168) showed significantly reduced disease activity associated with MS. Herein, we report the radiosynthesis of [11C]Tolebrutinib ([11C]5) as a potential PET imaging agent for BTK. The N-[11C]acrylamide moiety of [11C]5 was labeled by 11C-carbonylation starting from [11C]CO, iodoethylene, and the secondary amine precursor via a novel palladium-NiXantphos-mediated carbonylation protocol, and the synthesis was fully automated using a commercial carbon-11 synthesis platform (TracerMaker™, Scansys Laboratorieteknik). [11C]5 was obtained in a decay-corrected radiochemical yield of 37 ± 2% (n = 5, relative to starting [11C]CO activity) in >99% radiochemical purity, with an average molar activity of 45 GBq/μmol (1200 mCi/μmol). We envision that this methodology will be generally applicable for the syntheses of labeled N-acrylamides.
Bruton酪氨酸激酶(BTK)是B细胞受体信号通路中的关键组分,因此成为体内成像B细胞恶性肿瘤以及利用正电子发射断层扫描(PET)进行多发性硬化症(MS)研究的目标。最近的一项2b期研究采用了赛诺菲的BTK抑制剂Tolebrutinib(也称为SAR442168,PRN2246或BTK'168),显示出与MS相关的疾病活动显著减少。在此,我们报告了[11C]Tolebrutinib ([11C]5)的放射合成,这是一种潜在的BTK PET成像剂。[11C]5的N-[11C]丙烯酰胺部分通过新型的钯-NiXantphos介导的羰基化协议,从[11C]CO、碘乙烯和二级胺前体开始进行11C-羰基化标记,并且合成完全自动化使用商业碳-11合成平台(TracerMaker™,Scansys Laboratorieteknik)。[11C]5获得的衰减校正的放射化学产率为37 ± 2%(n = 5,相对于起始的[11C]CO活性),放射化学纯度>99%,平均摩尔活度为45 GBq/μmol(1200 mCi/μmol)。我们设想这种方法将普遍适用于标记的N-丙烯酰胺的合成。