Microfluidic radiosynthesis of [¹⁸F]FEMPT, a high affinity PET radiotracer for imaging serotonin receptors

• Thomas Lee Collier,
• Steven H. Liang,
• J. John Mann,
• Neil Vasdev and
• J. S. Dileep Kumar

Beilstein J. Org. Chem. 2017, 13, 2922–2927, doi:10.3762/bjoc.13.285

• Psychiatric Institute, New York, NY, USA 10.3762/bjoc.13.285 Abstract Continuous-flow microfluidics has shown increased applications in radiochemistry over the last decade, particularly for both pre-clinical and clinical production of fluorine-18 labeled radiotracers. The main advantages of microfluidics are

• receptor, [18F]FEMPT (pKi = 9. 79; Ki = 0.16 nM) by microfluidic radiochemistry. [18F]FEMPT was obtained in ≈7% isolated radiochemical yield and in >98% radiochemical and chemical purity. The molar activity of the final product was determined to be >148 GBq/µmol (>4 Ci/µmol). Keywords: agonist; fluorine

• longer half-life enables imaging protocols that can provide a better match of the pharmacokinetics of binding to the half-life of the radionuclide, as well as simplified radiochemistry protocols and the long-term goal of distribution for multicenter clinical trials. Several reports on the use of

Use of 3-[¹⁸F]fluoropropanesulfonyl chloride as a prosthetic agent for the radiolabelling of amines: Investigation of precursor molecules, labelling conditions and enzymatic stability of the corresponding sulfonamides

• Reik Löser,
• Steffen Fischer,
• Achim Hiller,
• Martin Köckerling,
• Uta Funke,
• Aurélie Maisonial,
• Peter Brust and
• Jörg Steinbach

Beilstein J. Org. Chem. 2013, 9, 1002–1011, doi:10.3762/bjoc.9.115

• of the analogous fluoroacetamide. Keywords: fluorine-18; hydrolytic metabolism; prosthetic groups; radiochemistry; sulfonamides; Introduction The importance of molecular imaging, i.e., the characterisation and measurement of biological processes in living organisms at the molecular level using

• to be modified with fluorine. For this purpose, generic groups that allow both derivatisation with fluorine as well as convenient introduction of radiofluorine are often used. These groups are referred to as prosthetic groups in preparative radiochemistry. For labelling with fluorine-18, a variety of

• multipolar contacts including hydrogen bonds [35], as observed herein. To our knowledge, all sulfonamides shown in Scheme 2 and Scheme 3 have not been described so far. Radiochemistry The sulfonate precursor molecules 3 and 4 were subjected to nucleophilic substitution with [18F]fluoride. The reaction