{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T07:16:07Z","timestamp":1790666167000,"version":"4.1.0"},"reference-count":33,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2022,6,22]],"date-time":"2022-06-22T00:00:00Z","timestamp":1655856000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"European Union\u2019s Horizon 2020 research and innovation program","award":["813528"],"award-info":[{"award-number":["813528"]}]},{"name":"European Union\u2019s Horizon 2020 research and innovation program","award":["670261"],"award-info":[{"award-number":["670261"]}]},{"name":"European Union\u2019s EU Framework Programme for Research and Innovation Horizon 2020","award":["813528"],"award-info":[{"award-number":["813528"]}]},{"name":"European Union\u2019s EU Framework Programme for Research and Innovation Horizon 2020","award":["670261"],"award-info":[{"award-number":["670261"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Radiolabeling of tetrazines has gained increasing attention due to their important role in pretargeted imaging or therapy. The most commonly used radionuclide in PET imaging is fluorine-18. For this reason, we have recently developed a method which enables the direct aromatic 18F-fluorination of tetrazines using stannane precursors through copper-mediated fluorinations. Herein, we further optimized this labeling procedure. 3-(3-fluorophenyl)-1,2,4,5-tetrazine was chosen for this purpose because of its high reactivity and respective limited stability during the labeling process. By optimizing parameters such as elution conditions, precursor amount, catalyst, time or temperature, the radiochemical yield (RCY) could be increased by approximately 30%. These conditions were then applied to optimize the RCY of a recently successfully developed and promising pretargeting imaging agent. This agent could be isolated in a decay corrected RCY of 14 \u00b1 3% and Am of 201 \u00b1 30 GBq\/\u00b5mol in a synthesis time of 70 min. Consequently, the RCY increased by 27%.<\/jats:p>","DOI":"10.3390\/molecules27134022","type":"journal-article","created":{"date-parts":[[2022,6,22]],"date-time":"2022-06-22T23:11:19Z","timestamp":1655939479000},"page":"4022","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":16,"title":["Optimization of Direct Aromatic 18F-Labeling of Tetrazines"],"prefix":"10.3390","volume":"27","author":[{"given":"Ida Vang","family":"Andersen","sequence":"first","affiliation":[{"name":"Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100 Copenhagen, Denmark"},{"name":"Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Roc\u00edo","family":"Garc\u00eda-V\u00e1zquez","sequence":"additional","affiliation":[{"name":"Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100 Copenhagen, Denmark"},{"name":"Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-1012-8644","authenticated-orcid":false,"given":"Umberto Maria","family":"Battisti","sequence":"additional","affiliation":[{"name":"Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7788-513X","authenticated-orcid":false,"given":"Matthias M.","family":"Herth","sequence":"additional","affiliation":[{"name":"Department of Drug Design and Pharmacology, Faculty of Health and Medical Sciences, University of Copenhagen, Jagtvej 160, 2100 Copenhagen, Denmark"},{"name":"Department of Clinical Physiology, Nuclear Medicine & PET, Rigshospitalet, Blegdamsvej 9, 2100 Copenhagen, Denmark"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,6,22]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"5772","DOI":"10.1039\/c3ob40897c","article-title":"Bioorthogonal chemistry for pre-targeted molecular imaging\u2014Progress and prospects","volume":"11","author":"Carroll","year":"2013","journal-title":"Org. 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