【摘要】 为制备瑞德西韦药代动力学研究所必需的放射性示踪剂，以N, N-二甲基[¹⁴C]甲酰胺为同位素原料，经亲电取代、分子间环化、碘代、亲核加成、羟基保护等十步放射性反应，反相高效液相色谱（HPLC）纯化和手性HPLC拆分获得目标物（217.7 MBq,光学纯度（ee）>99%），总放化收率为4.3%。经核磁共振氢谱（¹H NMR）、质谱（MS）和在线放射性高效液相色谱（HPLC-FSA）分析确认，目标物为[吡咯并三嗪环-4-¹⁴C]瑞德西韦。放射性薄层成像分析（TLC-IIA）、离线放射性高效液相色谱分析（HPLC-LSC）、在线放射性高效液相色谱-二极管阵列检测器/质谱联用（HPLC-FSA/PDA/MS）、液体闪烁测量（LSC）和HPLC-MS/MS分析表明，所得标记物的放化纯度和化学纯度均大于98%，比活度为2 069.8 MBq/mmol，放射性/非放射性单一杂质含量均小于1%，该标记物可作为示踪剂，用于瑞德西韦的放射性药代动力学等研究。更多还原

【Abstract】 To prepare the radiotracer for the pharmacokinetics study of Remdesivir, the ¹⁴C labelled Remdesivir at 4-C in pyrrolo[2,1-f][1,2,4]triazine moiety was synthesized via ten-step reaction. Firstly,nonradioactive 1H-pyrrole was formylated with N,N-dimethyl[¹⁴C]formamide and phosphorus oxychloride in dichloroethane at 0-15 ℃, followed by cyanidation with hydroxylamine in the solution of potassium hydroxide and amination with O-（2,4-dinitrophenyl）hydroxylamine in tetrahydrofuran at 0-15 ℃. The resulting product 5 was cyclized with formamidine acetate in the presence of tribasic potassium phosphate in EtOH at 78 ℃, and then iodinated with N-iodosuccinimide to obtain the key intermediate 7-iodo[4-¹⁴C]pyrrolo[2,1-f][1,2,4]triazin-4-amine（compound 7-1） in DMF at 0 ℃. Secondly, the intermediate 7-1 was substituted by the nonradioactive intermediate 7-2 and then cyanided to achieve the intermediate 9 at-65--60 ℃. The protecting benzyls in intermediate 9 were deprotected with boron trichloride in dichloromethane at-65--60 ℃, and two secondary hydroxyls of the deprotected product were selectively protected with acetone in the presence of TsOH in 2,2-dimethoxypropane at 25 ℃. Thirdly, the resulting product 11-1 was phosphated with the nonradioactive intermediate 11-2 and tert-butylmagnesium chloride in tetrahydrofuran at 0-20 ℃, and then deprotected with acetic acid at 100 ℃ to obtain the carbon-14labelled product Remdesivir as racemic mixture 13. Finally, the target product ¹⁴C labelled Remdesivir(compound 2b, 2-ethylbutyl N-[({[（2R,3S,4R,5R）-5-(4-amino[4-¹⁴C]pyrrolo[2,1-f][1,2,4]triazin-7-yl)-5-cyano-3,4-dihydroxytetrahydro-2-furyl]methyl}oxy)（oxo）（phenyloxy）-λ⁵-phosphanyl]-L-alaninate;217.7 MBq, optical ee>99%) was obtained in the ten-step chemical/radiochemical yield of 4.3% after the purification by using preparative RP-HPLC and resolution of the racemic mixture by using chiral semipreparative HPLC. The product 2b was compared with the standard sample of nonradioactive Remdesivir and charactered by ¹H NMR, ESI-MS, and HPLC-FSA. Its technical data（radiochemical/chemical purity>98%, specific activity 2 069.8 MBq/mmol, content of radioactive/nonradioactive single impurity <1%）was determined by TLC-IIA, HPLC-LSC, HPLC-FSA/PDA/MS, LSC, and HPLC-MS/MS. The following tracing study indicates that the target product can be used as radiotracer in the radiopharmacokinetics study of Remdesivir.更多还原