Reaction of [18F]4-fluorobenzenediazonium cations with cysteine or the cysteinyl group: preparation of18F-labeled S-aryl-cysteine and a radiolabeled peptide
作者:J. T. Patt、M. Patt
DOI:10.1002/jlcr.635
日期:2002.12
A reaction route for the preparation of no-carrier-added (n.c.a.) [18F]S-4-fluorophenylcysteine 7 via the [18F]-4-fluorobenzenediazonium ion 4 is described. The key step in this radiosynthesis is the reaction of 4 with cysteine forming [18F]4-fluorophenyldiazocysteine 6, which is subsequently converted into 7 by irradiation with 366 nm light. 4 was synthesized by reacting 1,4-dinitrobenzene 1 with [18F]-fluoride in acetonitrile in a PEEK-capillary in a microwave oven. After dilution of the reaction mixture with methanol, the resulting [18F]4-fluoro-1-nitrobenzene 2 was submitted to reduction by means of H2 with Pd on C catalyst. The resulting [18F]4-fluoroaniline 3 was purified by HPLC and diazotized to 4. The preparation of 4 was optimized with regard to yield and purity. The radiochemical yield of 6 was >90% (based on 3) while after UV irradiation and HPLC purification 45% of 7 (based on 3) was obtained (yields corrected for decay). The suitability of this method for labeling peptides with fluorine-18 was demonstrated by application to the tripeptide, glutathione (GSH; γ-L-glutamyl-L-cysteinyglycine) 8. Copyright © 2002 John Wiley & Sons, Ltd.
描述了一种通过[18F]-4-氟苯二氮离子4制备无载体添加(n.c.a.)[18F]S-4-氟苯丙氨酸7的反应路线。本放射合成的关键步骤是4与半胱氨酸反应形成[18F]4-氟苯基二氮半胱氨酸6,随后通过366纳米光照射转化为7。4的合成是通过将1,4-二硝基苯1与[18F]-氟化物在微波炉中的PEEK毛细管中于乙腈中反应得到的。在用甲醇稀释反应混合物后,得到的[18F]4-氟-1-硝基苯2通过Pd/C催化剂与氢气还原。得到的[18F]4-氟苯胺3经过HPLC纯化并重氮化为4。4的制备在产率和纯度上得到了优化。6的放射化学产率超过90%(基于3),而在紫外线照射和HPLC纯化后,获得了7的产率为45%(基于3,已校正衰变)。通过应用于三肽谷胱甘肽(GSH;γ-L-谷氨酸-L-半胱氨酸-甘氨酸)8,证明了该方法在用氟-18标记肽类方面的适用性。版权 © 2002 John Wiley & Sons, Ltd.