近年来，心力衰竭的死亡率日益增加，需要早期诊断和治疗。去甲肾上腺素转运体（NET）是可转运神经递质的转运蛋白，是治疗和诊断心衰的一个重要靶点。碘-123标记的间碘苄胍（¹²³I-MIBG）是目前临床上使用最广泛的NET靶向示踪剂，可用于单光子发射计算机断层扫描（SPECT）成像，但在体内不稳定。正电子发射断层扫描（PET）成像具有更优良的灵敏度和准确度，PET类NET靶向示踪剂陆续被开发。在MIBG类似物——苄胍类化合物中，本课题组选择了性能最好的溴作为间位取代基，选择与N-[3-溴-4-(3-[¹⁸F]氟-丙氧基)-苄基]胍（LMI1195）相同的3-氟丙氧基作为对位取代基，设计出一种新型的¹⁸F标记的NET靶向分子[¹⁸F]FP2BG，该探针分子亲和性良好，药代动力学性质良好，但标记路线复杂，标记产率低。为优化该标记方法，提高标记产率，本课题组继续优化标记合成路线，用叔丁氧羰基（Boc）保护胍基，并计划完成[¹⁸F]FP2BG理化性质、细胞实验、生物分布和PET显像的研究。

In recent years, the mortality rate of heart failure has been increasing day by day and requires early diagnosis and treatment. Norepinephrine transporter (NET) can transport neurotransmitters and is an important target for the treatment and diagnosis of heart failure. [¹²³I]Meta-iodobenzylguanidine (MIBG) is currently the most widely used NET targeted tracer in clinic and can be used for single-photon emission computed tomography (SPECT) imaging. Positron emission tomography (PET) imaging has better sensitivity and accuracy, and NET targeted tracers for PET imaging have been developed one after another. Among the MIBG analogs, benzidine guanidine compounds, our group selected the bromine as the meta substituent, and 3-fluoropropoxy group as the para-substituent the same with N-[3-Bromo-4-(3-[¹⁸F]fluoro-propoxy)-benzyl]-guanidine(LMI1195) to design a new ¹⁸F-labeled NET targeting molecule [¹⁸F]FP2BG. It has good targeting affinity and good pharmacokinetic properties. However, the marking route is complicated and the yield is low. In order to optimize the labeling method and increase the labeling yield, the research group continued to optimize the synthetic route, completely protected the guanidino group with t-butoxycarbonyl(Boc), and planned to complete the physical and chemical properties experiment of [¹⁸F]FP2BG , cell experiments, biodistribution and PET imaging experiments.