Synthesis of [3-<i>N</i>-<sup>11</sup>C-methyl]temozolomide via<i>in situ</i>activation of 3-<i>N</i>-hydroxymethyl temozolomide and alkylation with [<sup>11</sup>C]methyl iodide
作者:Jonas Eriksson、Rolph Van Kooij、Robert C. Schuit、Femke E. Froklage、Jaap C. Reijneveld、N. Harry Hendrikse、Albert D. Windhorst
DOI:10.1002/jlcr.3251
日期:2015.3
Temozolomide is a chemotherapeutic drug that is mainly used in the treatment of primary glioblastoma multiforme and recurrent high-grade glioma. Here, we report an efficient good manufacturing practice compliant method for the synthesis of [3-N-11C-methyl]temozolomide from 3-N-hydroxymethyl temozolomide that cleaves off formaldehyde in situ and becomes activated towards alkylation with [11C]methyl iodide. The labelling method was developed for an on-going patient study in which the predictive value of [3-N-11C-methyl]temozolomide and positron emission tomography on the outcome of temozolomide treatment is being investigated. The precursor was reacted with [11C]methyl iodide in the presence of 1,8-diazabicyclo[5.4.0]undec-7-ene in acetonitrile, heated at stepwise increasing temperature. Purification by semipreparative HPLC with pharmaceutical grade eluent and filtration gave approximately 10 mL sterile product solution ready for injection containing 1.55 ± 0.38 GBq (n = 5), the specific activity was 88 ± 25 GBq/µmol and the radiochemical purity was 98.5 ± 1.9%. 13C-NMR spectroscopy confirmed the labelled position after colabelling with 11C and 13C.
替莫唑胺是一种主要用于治疗原发性多形性胶质母细胞瘤和高级别胶质瘤复发的化疗药物。在此,我们报道了一种符合良好生产规范的高效合成方法,用于从3-N-羟甲基替莫唑胺合成[3-N-11C-甲基]替莫唑胺,该方法能在原位裂解甲醛并激活其与[11C]甲基碘的烷基化反应。这种标记方法是为一项正在进行的研究设计的,该研究旨在探讨[3-N-11C-甲基]替莫唑胺和正电子发射断层扫描技术对替莫唑胺治疗结果的预测价值。在存在1,8-二氮杂双环[5.4.0]十一碳-7-烯的情况下,将前体与[11C]甲基碘在乙腈中反应,并逐步升高温度加热。通过半制备型高效液相色谱法,使用符合药用级别的洗脱液和过滤,获得了约10毫升无菌产品溶液,可直接用于注射,其中含有1.55 ±0.38吉贝克(n=5),比活性为88 ±25吉贝克/微摩尔,放射化学纯度为98.5 ±1.9%。通过13C-核磁共振光谱法,在与11C和13C共同标记后确认了标记位置。