Chemistry with [18F]Fluoride Ion

The success of molecular imaging with positron-emission tomography (PET) depends on the availability of selective molecular probes labeled with positron-emitters, such asfluorine-18 (t1/2 = 109.7 min). No-carrier-added (NCA) [18F]fluoride ion (18F–) is the primary reagent for the preparation of 18F-labeled tracers in high specific activity. In this microreview, we survey current and advancing radiochemical methods and technologies for the use of NCA [18F]fluoride ion in the preparation of 18F-labeled radiotracers for applications with PET. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)

[1]  C. Crouzel,et al.  2‐[18F]fluoropyridines by no‐carrier‐added nucleophilic aromatic substitution with [18F]FK‐K222—a comparative study , 1999 .

[2]  W. Perrie,et al.  Microfluidic reactor for the radiosynthesis of PET radiotracers. , 2006, Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.

[3]  J. Katzenellenbogen,et al.  Facile nucleophilic fluorination reactions using tert-alcohols as a reaction medium: significantly enhanced reactivity of alkali metal fluorides and improved selectivity. , 2008, The Journal of organic chemistry.

[4]  Paul Watts,et al.  Syntheses of 11C- and 18F-labeled carboxylic esters within a hydrodynamically-driven micro-reactor. , 2004, Lab on a chip.

[5]  V. Pike,et al.  Nucleophilic substitution at cyclic sulphamates—routes to NCA [18F]fluoro-analogues of MK 801 , 1989 .

[6]  Sean R. Donohue,et al.  Radiolabeling of a high potency cannabinoid subtype‐1 receptor ligand, N‐(4‐fluoro‐benzyl)‐4‐(3‐(piperidin‐1‐yl)‐indole‐1‐sulfonyl)benzamide (PipISB), with carbon‐11 or fluorine‐18 , 2008 .

[7]  V. Pike,et al.  Recommendation for a practical production of [2-18F]fluoro-2-deoxy-D-glucose , 1987 .

[8]  R. Chirakal,et al.  Enzymatic synthesis of (−)-6-[18F]-fluoronorepinephrine from 6-[18F]-fluorodopamine by dopamine β-hydroxylase , 1998 .

[9]  H. Wadsworth,et al.  A solid-phase route to 18F-labeled tracers, exemplified by the synthesis of [18F]2-Fluoro-2-deoxy-D-glucose. , 2007, Angewandte Chemie.

[10]  V. Pike,et al.  Fluoridation of heteroaromatic iodonium salts—experimental evidence supporting theoretical prediction of the selectivity of the process , 2000 .

[11]  F. Diederich,et al.  Fluorine in Pharmaceuticals: Looking Beyond Intuition , 2007, Science.

[12]  Haoran Sun,et al.  Competitive demethylation and substitution in N,N,N-trimethylanilinium fluorides , 2007 .

[13]  Ming-fang Wang,et al.  Fully automated synthesis module for preparation of S-(2-[(18)F]fluoroethyl)-L-methionine by direct nucleophilic exchange on a quaternary 4-aminopyridinium resin. , 2003, Nuclear medicine and biology.

[14]  D. Albanese,et al.  HYDRATED TETRABUTYLAMMONIUM FLUORIDE AS A POWERFUL NUCLEOPHILIC FLUORINATING AGENT , 1998 .

[15]  B. Gulyás,et al.  PET evaluation of novel radiofluorinated reboxetine analogs as norepinephrine transporter probes in the monkey brain , 2004, Synapse.

[16]  M. Welch,et al.  A rapid and efficient method for the fluoroalkylation of amines and amides. Development of a method suitable for incorporation of the short-lived positron emitting radionuclide fluorine-18 , 1987 .

[17]  Jeih-San Liow,et al.  PET imaging of brain 5-HT1A receptors in rat in vivo with 18F-FCWAY and improvement by successful inhibition of radioligand defluorination with miconazole. , 2006, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[18]  F. Dollé Fluorine-18-labelled fluoropyridines: advances in radiopharmaceutical design. , 2005, Current pharmaceutical design.

[19]  H. Coenen,et al.  Preparation of N.C.A. [18F]-CH2BrF via aminopolyether supported nucleophilic substitution , 1986 .

[20]  V. Pike,et al.  New synthesis of diaryliodonium sulfonates from arylboronic acids , 2000 .

[21]  H. Atkins,et al.  Organic radiopharmaceuticals labeled with short-lived nuclides. 3. 18F-labeled phenylalanines. , 1971, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[22]  R. Iwata,et al.  Polymer-supported catalysts for efficient on-column preparation of 2-deoxy-2-[18F]fluoro-D-glucose , 1998 .

[23]  D. Bars,et al.  Fluorination of aromatic compounds from 1-aryl-3,3-dimethyltriazenes and fluoride anions in acidic medium: 2. Synthesis of (S)-[18F]-3-fluoro-α-methylphenylalanine , 2001 .

[24]  C. Zhan,et al.  Hydration of the Fluoride Anion: Structures and Absolute Hydration Free Energy from First-Principles Electronic Structure Calculations , 2004 .

[25]  Chi-Huey Wong,et al.  Enzymes for chemical synthesis , 2001, Nature.

[26]  J. Sutcliffe,et al.  Click for PET: rapid preparation of [18F]fluoropeptides using CuI catalyzed 1,3-dipolar cycloaddition , 2006 .

[27]  S. Stone-Elander,et al.  Microwave applications in radiolabelling with short-lived positron-emitting radionuclides , 2002 .

[28]  C. Halldin,et al.  PET for drug development. , 2004, Ernst Schering Research Foundation workshop.

[29]  Haoran Sun,et al.  Fluoride relay: a new concept for the rapid preparation of anhydrous nucleophilic fluoride salts from KF. , 2007, Chemical communications.

[30]  G. L. Watkins,et al.  Aryltrimethylammonium trifluoromethanesulfonates as precursors to aryl [18F]fluorides: Improved synthesis of [18F]GBR‐13119 , 1989 .

[31]  R. Schirrmacher,et al.  Recent Developments and Trends in 18F-Radiochemistry: Syntheses and Applications , 2007 .

[32]  J. Votaw,et al.  Production of reactive fluorine-18. , 1986, International journal of radiation applications and instrumentation. Part A, Applied radiation and isotopes.

[33]  V. Pike,et al.  The synthesis of [18F]fluoroarenes from the reaction of cyclotron-produced [18F]fluoride ion with diaryliodonium salts , 1998 .

[34]  David J. Yang,et al.  PET Chemistry: The Driving Force in Molecular Imaging , 2007, Journal of Nuclear Medicine.

[35]  Sajinder K. Luthra,et al.  Automated PET radiosyntheses using microfluidic devices , 2007 .

[36]  F. Dollé,et al.  Radiosynthesis of 2-exo-(2′-[18F]Fluoro-3′-(4-fluorophenyl)-pyridin-5′-yl)-7-azabicyclo[2.2.1]heptane ([18F]F2PhEP), a potent epibatidine-based radioligand for nicotinic acetylcholine receptor PET imaging , 2006 .

[37]  Kazutoshi Suzuki,et al.  A practical route for synthesizing a PET ligand containing [18F]fluorobenzene using reaction of diphenyliodonium salt with [18F]F− , 2007 .

[38]  Christer Halldin,et al.  Preparation of highly specific radioactivity [18F]flumazenil and its evaluation in cynomolgus monkey by positron emission tomography. , 2005, Nuclear medicine and biology.

[39]  Cheryl L. Morse,et al.  Automated radiosynthesis of [18F]SPA-RQ for imaging human brain NK1 receptors with PET , 2006 .

[40]  C. Lemaire,et al.  No-carrier-added regioselective preparation of 6-[18F]fluoro-L-dopa. , 1990, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[41]  C. Crouzel,et al.  Chemistry of β +-Emitting Compounds Based on Fluorine-18 , 2002 .

[42]  N. Vasdev,et al.  On the preparation of fluorine-18 labelled XeF(2) and chemical exchange between fluoride ion and XeF(2). , 2002, Journal of the American Chemical Society.

[43]  D. Landini,et al.  Dramatic effect of the specific solvation on the reactivity of quaternary ammonium fluorides and poly(hydrogen fluorides), (HF)n.cntdot.F-, in media of low polarity , 1989 .

[44]  M. Argentini,et al.  Syntheses of 5-fluoro-d/l-dopa and [18F]5-fluoro-l-dopa , 1994 .

[45]  Henry N. Wagner,et al.  Clinical PET: its time has come. , 1991, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[46]  C. Kilts,et al.  18F-labeled FECNT: a selective radioligand for PET imaging of brain dopamine transporters. , 2000, Nuclear medicine and biology.

[47]  V. Pike,et al.  Novel use of an isotope separator to determine the position of fluorine-18 in labelled 1,1,1,2-tetrafluoroethanes , 1994 .

[48]  F. Wuest,et al.  Synthesis of 18F-labeled Neurotensin(8-13) via Copper-Mediated 1,3-Dipolar [3+2]Cycloaddition Reaction , 2007 .

[49]  M E Phelps,et al.  Positron emission tomography provides molecular imaging of biological processes. , 2000, Proceedings of the National Academy of Sciences of the United States of America.

[50]  Paul Watts,et al.  Micro reactors: principles and applications in organic synthesis , 2002 .

[51]  A. Horti,et al.  Synthesis of 6‐chloro‐3‐((2‐(S)‐azetidinyl)methoxy)‐5‐(2‐[18F]fluoropyridin‐4‐yl)pyridine ([18F]NIDA 522131), a novel potential radioligand for studying extrathalamic nicotinic acetylcholine receptors by PET , 2004 .

[52]  S. Houle,et al.  Synthesis of two radiofluorinated cocaine analogues using distilled 2-[18F]fluoroethyl bromide. , 1995, Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.

[53]  K. Hamacher,et al.  Efficient stereospecific synthesis of no-carrier-added 2-[18F]-fluoro-2-deoxy-D-glucose using aminopolyether supported nucleophilic substitution. , 1986, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[54]  M. Glaser,et al.  "Click labeling" with 2-[18f]fluoroethylazide for positron emission tomography. , 2007, Bioconjugate chemistry.

[55]  F. Dollé,et al.  2-, 3- and 4-[18F]Fluoropyridine by no-carrier-added nucleophilic aromatic substitution with K[18F]F-K222- a comparative study: 2-, 3- and 4-[18F] FLUOROPYRIDINE , 2003 .

[56]  M Schwaiger,et al.  Synthesis and radiopharmacology of O-(2-[18F]fluoroethyl)-L-tyrosine for tumor imaging. , 1999, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[57]  Kyung-Han Lee,et al.  Re-evaluation of 3-bromopropyl triflate as the percursor in the preparation of 3-[ 18F]fluoropropyl bromide 1 Presented in part at the Joint EANM and WFNM&B Congress, Berlin, Germany, August 30–September 4, 1998. 1 , 1999 .

[58]  M. Piel,et al.  Efficient synthesis of 2-bromo-1-[18F]fluoroethane and its application in the automated preparation of 18F-fluoroethylated compounds. , 2002, Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.

[59]  H. Atkins,et al.  Organic radiopharmaceuticals labeled with isotopes of short half-life. V. 18 F-labeled 5- and 6-fluorotryptophan. , 1972, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[60]  W. Wadsak,et al.  NCA nucleophilic radiofluorination on substituted benzaldehydes for the preparation of [18F]fluorinated aromatic amino acids. , 2006, Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.

[61]  V. Grushin Carboranylhalonium Ions: From Striking Reactivity to a Unified Mechanistic Analysis of Polar Reactions of Diarylhalonium Compounds , 1992 .

[62]  H. Coenen,et al.  The N.C.A. nucleophilic 18F‐fluorination of 1,N‐disubstituted alkanes as fluoroalkylation agents , 1987 .

[63]  M. Carroll,et al.  Diaryliodonium salts: a solution to 3-[18F]fluoropyridine† , 2007 .

[64]  A. Knöchel,et al.  Aromatic n.c.a. labelling with 18F- by modified Balz-Schiemann-decomposition☆ , 1991 .

[65]  G. Stocklin,et al.  Synthesis and quality control of long-chain 18F-fatty acids , 1980 .

[66]  M. K. Das,et al.  Fluorinated benzamide neuroleptics--III. Development of (S)-N-[(1-allyl-2-pyrrolidinyl)methyl]-5-(3-[18F]fluoropropyl)-2, 3-dimethoxybenzamide as an improved dopamine D-2 receptor tracer. , 1995, Nuclear medicine and biology.

[67]  V. Pike,et al.  An ab initio and MNDO-d SCF–MO computational study of the extrusion reactions of R2I–F iodine(III) via dimeric, trimeric and tetrameric transition states , 2000 .

[68]  A. Wolf,et al.  Nucleophilic aromatic substitution of activated cationic groups by 18F-labeled fluoride. A useful route to no-carrier-added (NCA) 18F-labeled aryl fluorides , 1985 .

[69]  J. Mazziotta,et al.  Positron emission tomography: human brain function and biochemistry. , 1985, Science.

[70]  O. Wallach Ueber das Verhalten einiger Diazo‐ und Diazoamidoverbindungen , 1886 .

[71]  G. L. Watkins,et al.  Multiphase extraction: rapid phase-transfer of [18F]fluoride ion for nucleophilic radiolabeling reactions. , 1988, International journal of radiation applications and instrumentation. Part A, Applied radiation and isotopes.

[72]  D. Bars,et al.  Fluorination of aromatic compounds from 1-aryl-3,3-dimethyltriazenes and fluoride anions in acidic medium , 2001 .

[73]  Mark S Gordon,et al.  Theoretical study of the solvation of fluorine and chlorine anions by water. , 2005, The journal of physical chemistry. A.

[74]  Synthesis and evaluation of N-(5-fluoro-2-phenoxyphenyl)-N-(2-[(18)F]fluoromethoxy-d(2)-5-methoxybenzyl)acetamide: a deuterium-substituted radioligand for peripheral benzodiazepine receptor. , 2005, Bioorganic & medicinal chemistry.

[75]  Dong Wook Kim,et al.  A new class of SN2 reactions catalyzed by protic solvents: Facile fluorination for isotopic labeling of diagnostic molecules. , 2006, Journal of the American Chemical Society.

[76]  M. Berridge,et al.  Improved synthesis of [18F]fluoromethyl tosylate, a convenient reagent for radiofluoromethylations , 2005 .

[77]  S. Gatley Rapid production and trapping of [18F]fluorotrimethylsilane, and its use in nucleophilic fluorine-18 labeling without an aqueous evaporation step. , 1989, International journal of radiation applications and instrumentation. Part A, Applied radiation and isotopes.

[78]  M J Welch,et al.  Synthesis and biodistribution of 18F-labeled fluoronitroimidazoles: potential in vivo markers of hypoxic tissue. , 1986, International journal of radiation applications and instrumentation. Part A, Applied radiation and isotopes.

[79]  G. Reischl,et al.  Electrochemical transfer of [18F]fluoride from [18O]water into organic solvents ready for labeling reactions , 2002 .

[80]  A. Reissell,et al.  Production of 18F from water targets. Specific radioactivity and anionic contaminants , 1988 .

[81]  R. Nickles,et al.  Synthesis and some characteristics of no-carrier added [18F]fluorotrimethylsilane. , 1985, The International journal of applied radiation and isotopes.

[82]  H. Coenen,et al.  Nucleophilic 18F-fluorination of heteroaromatic iodonium salts with no-carrier-added [18F]fluoride. , 2007, Journal of the American Chemical Society.

[83]  A. Bogni,et al.  [18F]fluoromethyl triflate, a novel and reactive [18F]fluoromethylating agent: preparation and application to the on-column preparation of [18F]fluorocholine. , 2002, Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.

[84]  Graham R. Smith,et al.  Radical scavengers: A practical solution to the reproducibility issue in the fluoridation of diaryliodonium salts , 2007 .

[85]  Efficient regioselective labelling of the CFC alternative 1,1,1,2-tetrafluoroethane (HFC-134a) with fluorine-18 , 1995 .

[86]  V. Pike,et al.  Reactions of cyclotron-produced [18F]fluoride with diaryliodonium salts—a novel single-step route to no-carrier-added [18]fluoroarenes , 1995 .

[87]  H. Burns,et al.  Positron emission tomography neuroreceptor imaging as a tool in drug discovery, research and development. , 1999, Current opinion in chemical biology.

[88]  K. Hamacher,et al.  C-Terminal 18F-fluoroethylamidation exemplified on [Gly-OH9] oxytocin† , 2002 .

[89]  M. Welch,et al.  Handbook of Radiopharmaceuticals: Radiochemistry and Applications , 2002 .

[90]  Dong Wook Kim,et al.  Facile S(N)2 reaction in protic solvent: quantum chemical analysis. , 2007, The journal of physical chemistry. A.

[91]  Haoran Sun,et al.  Room-temperature nucleophilic aromatic fluorination: experimental and theoretical studies. , 2006, Angewandte Chemie.

[92]  C. Mathis,et al.  A radiosynthesis of fluorine-18 fluoromisonidazole. , 1989, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[93]  M. Welch,et al.  Preparation and preliminary biodistribution of no carrier added fluorine-18 fluoroethanol , 1980 .

[94]  C. A. Ramsden,et al.  Xenon difluoride exchanges fluoride under mild conditions: a simple preparation of [(18)F]xenon difluoride for PET and mechanistic studies. , 2001, Journal of the American Chemical Society.

[95]  C. Halldin,et al.  Synthesis of a [6-pyridinyl-18F]-labelled fluoro derivative of WAY-100635 as a candidate radioligand for brain 5-HT1A receptor imaging with PET. , 2003, Bioorganic & medicinal chemistry.

[96]  R. Myers,et al.  The radiosynthesis of [18F]PK 14105 as an alternative radioligand for peripheral type benzodiazepine binding sites. , 1990, International journal of radiation applications and instrumentation. Part A, Applied radiation and isotopes.

[97]  Victor W. Pike,et al.  Integration of a microwave reactor with synthia to provide a fully automated radiofluorination module , 2007 .

[98]  Christine Ryan,et al.  Synthesis, characterization, and first successful monkey imaging studies of metabotropic glutamate receptor subtype 5 (mGluR5) PET radiotracers , 2005, Synapse.

[99]  M. Welch,et al.  NCA 16α-[18F]fluoroestradiol-17β: The effect of reaction vessel on fluorine-18 resolubilization, product yield, and effective specific activity , 1986 .

[100]  Ming-Rong Zhang,et al.  [18F]Fluoroalkyl agents: synthesis, reactivity and application for development of PET ligands in molecular imaging. , 2007, Current topics in medicinal chemistry.

[101]  M. Berridge,et al.  Synthesis of [18F]fluoromethyl iodide, a synthetic precursor for fluoromethylation of radiopharmaceuticals. , 2000, Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.

[102]  V. Pike,et al.  Facile synthesis of substituted diaryliodonium tosylates by treatment of aryltributylstannanes with Koser’s reagent , 1999 .

[103]  V. Pike,et al.  An ab initio and MNDO-d SCF-MO computational study of stereoelectronic control in extrusion reactions of R2I–F iodine(III) intermediates† , 1999 .

[104]  H. Coenen,et al.  N.C.A. 18F-fluoroacylation via fluorocarboxylic acid esters , 1988 .

[105]  H. Wikström,et al.  Alternative methods for labeling the 5-HT1A receptor agonist, 1-[2-(4-fluorobenzoylamino)ethyl]-4-(7-methoxynaphthyl)piperazine (S14506), with carbon-11 or fluorine-18 , 2005 .

[106]  A. Gee,et al.  Fluorinase mediated C-(18)F bond formation, an enzymatic tool for PET labelling. , 2006, Chemical communications.

[107]  P. Angelberger,et al.  Synthesis of fluorine‐18‐labelled 5‐ and 6‐fluoro‐2‐pyridinamine , 2006 .

[108]  Salvatore D. Lepore,et al.  Arylsulfonate-based nucleophile assisting leaving groups. , 2005, The Journal of organic chemistry.

[109]  W C Eckelman,et al.  Development of fluorine-18-labeled 5-HT1A antagonists. , 1999, Journal of medicinal chemistry.

[110]  Paul Watts,et al.  Micro reactors: a new tool for the synthetic chemist. , 2007, Organic & biomolecular chemistry.

[111]  C. Lemaire,et al.  Fluorine-18-altanserin: a radioligand for the study of serotonin receptors with PET: radiolabeling and in vivo biologic behavior in rats. , 1991, Journal of nuclear medicine : official publication, Society of Nuclear Medicine.

[112]  A. Wolf,et al.  Syntheses of no-carrier-added (NCA) [18F]fluoroalkyl halides and their application in the syntheses of [18F]fluoroalkyl derivatives of neurotransmitter receptor active compounds , 1987 .

[113]  T. Lyle,et al.  Fluoride-induced formation and ring opening of cyclic sulfamates from hydroxy triflamides: synthetic and mechanistic studies , 1987 .

[114]  Jeih-San Liow,et al.  Disulfiram Inhibits Defluorination of 18F-FCWAY, Reduces Bone Radioactivity, and Enhances Visualization of Radioligand Binding to Serotonin 5-HT1A Receptors in Human Brain , 2007, Journal of Nuclear Medicine.

[115]  A. Horti,et al.  Efficient synthesis of 6-chloro-3-((2-(S)-azetidinyl)methoxy)-5-((E)-2-(2-[18F]fluoropyridin-4-yl)vinyl)pyridine ([18F]NIDA 52289), a very high affinity radioligand for nicotinic acetylcholine receptors , 2004 .

[116]  Tove Grönroos,et al.  Synthesis and characterization of a potent, selective, radiolabeled substance-P antagonist for NK1 receptor quantitation: ([18F]SPA-RQ). , 2004, Molecular imaging and biology : MIB : the official publication of the Academy of Molecular Imaging.

[117]  C. Dence,et al.  No-carrier-added synthesis of 3-[18F]fluoro-1-(2-nitro-1-imidazolyl)-2-propanol. A potential PET agent for detecting hypoxic but viable tissues. , 1989, International journal of radiation applications and instrumentation. Part A, Applied radiation and isotopes.

[118]  C. Nahmias,et al.  Synthesis of 3,4-dihydroxy-5-fluoro-DL-phenylalanine and 3,4-dihydroxy-5-[fluorine-18]fluoro-DL-phenylalanine , 1973 .

[119]  B. Gulyás,et al.  Synthesis and PET evaluation of (R)‐[S‐methyl‐11C]thionisoxetine, a candidate radioligand for imaging brain norepinephrine transporters , 2006 .

[120]  D. Uguen,et al.  The sequel to a carbocyclic nucleoside synthesis: a divergent access to both arenediazonium ions and aryl triflates , 2004 .

[121]  H. Machulla,et al.  Synthesis of 6-[18F]fluoroveratraldehyde by nucleophilic halogen exchange at electron-rich precursors , 2006 .

[122]  M. Raichle,et al.  Preliminary studies with [18F]haloperidol: a radioligand for in vivo studies of the dopamine receptors , 1980, Brain Research.

[123]  B. Tavitian,et al.  Design and synthesis of a new [18F]fluoropyridine-based haloacetamide reagent for the labeling of oligonucleotides: 2-bromo-N-[3-(2-[18F]fluoropyridin-3-yloxy)propyl]acetamide. , 2004, Bioconjugate chemistry.

[124]  A. Gee,et al.  The first enzymatic method for C–18F bond formation: the synthesis of 5′‐[18F]‐fluoro‐5′‐deoxyadenosine for imaging with PET , 2003 .

[125]  L. Barré,et al.  Rapid synthesis of N,N′-disubstituted piperazines. Application to the preparation of No carrier added 1-(4-[18F]fluorophenyl)piperazine and of an [18F]-selective ligand of serotoninergic receptors (5HT2 antagonist) , 1992 .

[126]  F. Wüst,et al.  Synthesis of 4‐[18F]fluoroiodobenzene and its application in sonogashira cross‐coupling reactions , 2003 .

[127]  A. Luxen,et al.  Recommendations for fluorine-18 production , 1991 .

[128]  M. Reivich,et al.  Labeled 2-deoxy-D-glucose analogs. 18F-labeled 2-deoxy-2-fluoro-D-glucose, 2-deoxy-2-fluoro-D-mannose and 14C-2-deoxy-2-fluoro-D-glucose , 1978 .

[129]  G. Lucignani Pivotal role of nanotechnologies and biotechnologies for molecular imaging and therapy , 2006, European Journal of Nuclear Medicine and Molecular Imaging.

[130]  J. Mazziotta,et al.  Positron emission tomography and autoradiography: Principles and applications for the brain and heart , 1985 .

[131]  A. Wolf,et al.  Absolute Cross Sections for the Production of 18F via the 18O(p, n)18F Reaction , 1979 .

[132]  S. Quake,et al.  Multistep Synthesis of a Radiolabeled Imaging Probe Using Integrated Microfluidics , 2005, Science.

[133]  K. Hamacher,et al.  Electrochemical cell for separation of [18F]fluoride from irradiated 18O-water and subsequent no carrier added nucleophilic fluorination. , 2002, Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.

[134]  S. Oh,et al.  An efficient F-18 labeling method for PET study: Huisgen 1,3-dipolar cycloaddition of bioactive substances and F-18-labeled compounds , 2007 .

[135]  V. M. Vlasov Fluoride ion as a nucleophile and a leaving group in aromatic nucleophilic substitution reactions , 1993 .

[136]  A. Wolf,et al.  Separation of [18F]fluoride from [18O]water using anion exchange resin. , 1990, International journal of radiation applications and instrumentation. Part A, Applied radiation and isotopes.

[137]  Sami S Zoghbi,et al.  Synthesis and simple 18F-labeling of 3-fluoro-5-(2-(2-(fluoromethyl)thiazol-4-yl)ethynyl)benzonitrile as a high affinity radioligand for imaging monkey brain metabotropic glutamate subtype-5 receptors with positron emission tomography. , 2007, Journal of medicinal chemistry.

[138]  J. R. Grierson,et al.  Simplified Labeling Approach for Synthesizing 3′-Deoxy-3′-[18F]fluorothymidine ([18F]FLT) , 2000 .

[139]  Otto Muzik,et al.  Imaging proliferation in vivo with [F-18]FLT and positron emission tomography , 1998, Nature Medicine.

[140]  R. Nickles The production of a broader palette of PET tracers , 2003 .

[141]  O. Solin,et al.  Automated synthesis and purification of [18F]bromofluoromethane at high specific radioactivity. , 2001, Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.

[142]  M. Welch,et al.  Preparation of fluorine-18 aryl fluorides: piperidyl triazenes as a source of diazonium salts , 1979 .

[143]  V. Pike,et al.  Efficient and selective labelling of the CFC alternative, 1,1,1,2-tetrafluoroethane, with 18F in the 1-position , 1993 .

[144]  John R. Jones,et al.  Microwave-enhanced radiochemistry , 2000 .

[145]  H. Löwe,et al.  Chemistry in microstructured reactors. , 2004, Angewandte Chemie.

[146]  M. Vincent,et al.  The solvated fluoride anion can be a good nucleophile. , 2005, Chemical communications.

[147]  Christer Halldin,et al.  Differentiation of extrastriatal dopamine D2 receptor density and affinity in the human brain using PET , 2004, NeuroImage.

[148]  Ming-Rong Zhang,et al.  Development of an automated system for synthesizing 18F-labeled compounds using [18F]fluoroethyl bromide as a synthetic precursor. , 2002, Applied radiation and isotopes : including data, instrumentation and methods for use in agriculture, industry and medicine.

[149]  G. Schiemann,et al.  Über aromatische Fluorverbindungen, I.: Ein neues Verfahren zu ihrer Darstellung , 1927 .