bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of a radiotracer for studying serotonin uptake sites with positron emission tomography: [11C]McN‐5652‐Z
Authors: Suehiro Makiko , Ravert Hayden T. , Dannals Robert F. , Scheffel Ursula , Wagner Henry N. 
Published: October 2006

AbstractThe highly potent serotonin (5‐HT) uptake blocker, McN‐5652‐Z (trans‐1,2,3,5,6,10b ‐ hexahydro ‐ 6 ‐ [4 ‐ (methylthio)phenyl] pyrrolo ‐ [2,1‐a]‐isoquinoline) was labeled with 11C for studying serotonin uptake sites using positron emission tomography (PET). [11C]McN‐5652‐Z was synthesized by S‐methylation of the normethyl precursor with [11C]iodomethane in DMF at 30 ‐ 35° C. The radiosyntheses including purification by HPLC and formulation for injection were completed in an average of 16 minutes following the end of bombardment (E.O.B.) with an overall radiochemical yield of 12%. The average specific activity determined at the end of synthesis (E.O.S.) was approximately 4250 mCi/μmole; this corresponds to approximately 7350 mCi/μmole at E.O.B. [11C]McN‐5655‐Z, a less potent blocker, was also prepared by the same procedure.
Synthesis of [N‐C3H3]‐racemic‐trans‐1‐phenyl‐3‐dimethylamino‐6‐chloro‐7‐hydroxy‐1,2,3,4‐tetrahydronaphthalene (PAT‐6)
Authors: Wyrick Steven D. , Booth Raymond G. , Myers Andrew M. , Kula Nora S. , Baldessarini Ross J. 
Published: October 2006

AbstractThe biological function of the sigma receptor in the central nervous system is not well understood at the present time. Once thought to be an opiate receptor, the sigma receptor has now been shown to have a neuromodulatory effect upon the synthesis of dopamine in the striatal nerve terminal. A novel sigma agonist, racemic‐trans‐1‐phenyl‐3‐dimethylamino‐6‐chloro‐7‐hydroxy‐1,2,3,4‐tetrahydronaphthalene, PAT‐6, has demonstrated the greatest potency of any compound tested to date as a sigma agonist in stimulating the synthesis of dopamine in vitro and may be functioning at a novel sigma receptor subtype. The synthesis of tritiated PAT‐6 at high specific activity is described herein. This labeled ligand was prepared for use in radioreceptor binding studies in order to identify the putative sigma receptor subtype responsible for mediation of the stimulatory effect on in vitro dopamine synthesis.
Synthesis of [3H]‐VUF 4576; A new radiolabelled Ca2+‐antagonist
Authors: Caldirola P. , Timmerman H. 
Published: October 2006

AbstractThe new radiolabelled [3H]‐VUF 4576 has been prepared by an easy procedure using commercially available C3H3I. The new radiolabelled ligand [3H]‐VUF 4576 belongs to a subclass of prenylamine analogues which interfere with calcium regulated pathways. The compound has been synthesized in order to study the interaction of other compounds with these mechanisms and in particular the site of action of this subclass of calcium entry blockers and calmodulin antagonists.
Synthesis of N‐[11C]‐methyl‐L‐DOPA
Authors: Horti Andrew , Ravert Hayden T. , Dannals Robert F. , Wagner Henry N. 
Published: October 2006

AbstractThe radiochemical synthesis of N‐[11C‐methyl]‐L‐DOPA was accomplished by N‐methylation of the methyl and ethyl esters of L‐N‐tert‐butyl‐oxycarbonyl‐[β‐(3,4‐dimethoxyphenyl)] alaninate with [11C]iodomethane using sodium hydride in tetrahydrofuran and deprotection of the N‐methyl intermediate with hydriodic acid. A catalytic influence of Kryptofix on the methylation reaction was observed. Using the ethyl ester precursor, the average specific activity at the end‐of‐synthesis was 972 mCi/μmole. The synthesis was completed in an average of 45 minutes following the end‐of‐bombardment.
Neuropeptides labelled with 35S
Authors: Kaspersen Frans M. , van Nispen Jan W. , Sperling Eric M. G. , Vader Jan F. 
Published: October 2006

AbstractMethionine and cysteine containing peptides can be labelled with 35S by coupling of 35S‐cysteine or 35S‐methionine with a large excess of suitably protected peptide precursors. This is illustrated for [pGlu4, Cyt6]AVP‐(4‐9), β‐endorphin‐(5‐17) and the ACTH‐fragment‐analogue Org 2766. Using HPLC as final purification the peptides are obtained in radiochemical yields of about 5% and radiochemical purities between 90‐97%. However the specific activities obtained are much lower than the specific activities of the starting 35S‐amino acids.
Preparation of 9‐cis‐retinoic acid [11,12‐3H(N)] by photochemical isomerization
Authors: Dawson Marcia I. , Hobbs Peter D. , Cameron James F. , Rhee Sung W. 
Published: October 2006

AbstractAll‐trans‐Retinoic acid [11,12‐3H(N)] was photochemically isomerized using a fluorescent source to afford a mixture of isomeric retinoic acids, from which 9‐cis‐retinoic acid[11,12‐3H(N)] was isolated by reversed‐phase HPLC. The identity of 9‐cis‐retinoic acid [11, 12‐3H2] was confirmed by coinjection with the unlabeled acid.
Convenient preparation of Boc‐L‐[4‐15N]asparagine and ‐[5‐15N]glutamine for application in peptide synthesis
Authors: Lankiewicz Leszek , Grehn Leif , Ragnarsson Ulf 
Published: October 2006

AbstractThe title compounds have been prepared by a simple and economical procedure from the corresponding Bocprotected α‐benzyl esters and [15N]ammonia with N,N′‐carbonyldiimidazole as coupling agent. Catalytic hydrogenolysis furnished both labelled products in high overall yields suitable for synthetic work.
Synthesis of [1′,3′,4′‐3H3]4‐(5′,6′,7′,8′‐tetrahydro‐5′,5′,8′,8′‐tetramethyl‐2′‐anthracenyl)benzoic acid for binding studies of retinoic acid receptors
Authors: Dawson Marcia I. , Hobbs Peter D. , Rhee Sung W. , Morimoto Hiromi , Williams Philip G. 
Published: October 2006

Abstract[1′,3′,4′‐3H3]4‐(5′,6′,7′,8′‐Tetrahydro‐5′,5′,8′,8′‐tetramethyl‐2′‐anthracenyl)benzoic acid (specific activity 64 Ci/mmole) was synthesized by bromination of ethyl 4‐(5′,6′,7′,8′‐tetrahydro‐5′,5′,8′,8′‐tetramethyl‐2′‐antracenyl)benzoate, followed by reductive debromination by tritium gas in the presence of 10% palladium on carbon and hydrolysis. 1H and 3H NMR spectroscopy was used to establish tritium at 1′,3′,4′‐tetrahydroanthracenyl ring positions.
Synthese de la [15N]‐cysteamine
Authors: Lagoueyte Catherine , Subra G. , Bonnet P. A. , Fernandez J. P. , Roman V. , Fatome M. , Chapat J. P. 
Published: October 2006

AbstractThe synthesis of the radioprotector [15N]‐cysteamine from [15N]‐glycine is described. Cysteamine is labelled by 15N in order to study its interaction with phospholipidic membranes by 15N NMR.
Synthesis of 17α‐[(E)‐2‐[125I]iodoethenyl]androsta‐4,6‐dien‐17β‐ol‐3‐one, an active‐site‐directed photoaffinity radiolabel for androgen‐binding proteins
Authors: Cruz Pablo J. Diaz , Smith Howard E. , Danzo Benjamin J. , Clanton Jeffrey A. , Mason N. Scott 
Published: October 2006

AbstractThe active‐site‐directed photoaffinity radiolabel for androgen‐binding proteins, 17α‐[(E)‐2‐[125I]iodoethenyl]androsta‐4,6‐dien‐17β‐ol‐3‐ one, was prepared by reaction of 17α‐[(E)‐2‐tributyltin(IV)ethenyl]androsta‐4,6‐dien‐17β‐ol‐3‐one with carrier added sodium iodide‐125 in the presence of hydrogen peroxide and acetic acid. Purification by HPLC gave the radiolabeled steroid in 52% radiochemical yield with a specific activity of 27 Ci/mmol and 100% radiochemical purity.
211At‐labelling of polymer particles for radiotherapy: Synthesis, purification and stability
Authors: Larsen Roy H. , Hassfjell Sindre P. , Hoff Per , Alstad Jorolf , Olsen Eivind , Vergote Ignace B. , de Vos Laure N. , Bjørgum Jon , Nustad Kjell 
Published: October 2006

AbstractCyclotron‐produced 211At was distilled from a Bi metal target and coupled to N‐succinimidyl‐3‐(trimethylstannyl)benzoate. The resulting N‐succinimidyl‐3‐(211At)astatobenzoate was thereafter coupled to aminated monosized polymer particles with a diameter of 1.8 μm. The total time elapsed from the end of the cyclotron irradiation until the final product was prepared was about 2.5 hours. From 23 to 51% of the target activity at the end of bombardment was measured in the final conjugate. Solid‐liquid extraction purification of the astatinated intermediate, using Sep‐pak columns (Waters), gave more reproducible yields in the final conjugation step. The 211At‐labelled particles were incubated with fetal calf serum, human serum and human full blood at room temperature. The 211At activity on the particles was measured before and after three times washing at 4, 24 and 48 hours. The stability was not significantly different from 100% for all media and for all time points. This indicates that 211At‐labelled particles can be stable under in vivo conditions, and may thereby be a promising agent for intracavitary radiotherapy on freefloating cancer cells or surface fixed cells.
A facile and improved synthesis of 17α‐{2‐(E)‐[1 2 5 I]‐iodovinyl}‐19‐nortestosterone, a no‐carrier‐added ligand for progesterone receptor analyses
Authors: Damodaran Kalyani M. , Epperly Michael W. , Pillai K. M. R. , Bloomer William D. 
Published: October 2006

AbstractStrategies for human breast cancer therapy using 125I‐labeled steroid hormones are clinically attractive in light of the estrogen dependence of and progestogen receptor involvement in many cancers and the favorable microdosimetry resulting from 125I decay. We have synthesized the no‐carrier‐added progesterone receptor ligand 17α‐{2‐(E)‐[125I]‐iodovinyl}‐19‐nortestosterone (E‐125IVNNT) by a simple and high yielding method, and determined its uptake and specific progesterone receptor binding in vitro using T47D human breast carcinoma cells. The ligand was prepared by [125I]‐iododestannylation of 17α‐[2‐(E)‐tri‐n‐butylstannylvinyl]‐19‐nortestosterone (E‐TBSVNNT) by using the rare iodinating agent [125I]‐sodium iodide/ferric sulfate in mixed dichloromethane‐water solvent. Cell binding assays demonstrated that E‐125IVNNT binding to T47D breast carcinoma was specific and saturable with an affinity for the progesterone receptor 10‐fold greater than that of 3H‐R5020.
Synthesis of [123I]tert‐butyl 8‐iodo‐5,6‐dihydro‐5‐methyl‐6‐oxo‐4H‐imidazo[1,5‐a][1,4]benzodiazepine 3‐carboxylate, a potential SPECT imaging agent for diazepam‐insensitive (DI) benzodiazepine receptors
Authors: He Xiao‐Shu , Matecka Dorota , Lee Kan Sam , Gu Zi‐Qiang , Rice Kenner C. , Wong Garry , Skolnick Phil , De Costa Brian R. 
Published: October 2006

Abstract[123I]tert‐Butyl 8‐iodo‐5,6‐dihydro‐5‐methyl‐6‐oxo‐4H‐imidazo [1,5‐a][1,4]benzodiazepine 3‐carboxylate ([123I]3), a high affinity and selective radioligand for the diazepam insensitive (DI) benzodiazepine receptor was synthesized in 2 steps from tert‐butyl 8‐bromo‐5,6‐dihydro‐5‐methyl‐6‐oxo‐4H‐imidazo[1,5‐a][1,4]benzodiazepine 3‐carboxylate (4). A key step in the synthesis of this potential SPECT imaging agent utilized (Ph3P)3Pd mediated stannylation of 4 with (Bu3Sn)2 to the corresponding 8‐tributyltin derivative 5. Iododestannylation of 5 with no carrier added [123]NaI in aqueous ethanolic CH3CO3H furnished [123I]3 (85%) in greater than 98% radiochemical purity following TLC purification.
Synthesis of [35S]phosphorothionate insecticides : The example of [35S] fenthion
Authors: Dias Marylène , Mornet René , Kotoujansky Alain 
Published: October 2006

AbstractA general method for the synthesis of [35S]phosphorothionates is proposed, based on the example of [35S]fenthion. This consists of reacting molecular 35S with the corresponding phosphites which are easily prepared from commercial precursors.
Synthesis and biological evaluation of iodine‐125 iodocaramiphen. A potential M1 muscarinic imaging agent for SPECT
Authors: McPherson Daniel W. , Knapp F. F. (Russ) , Hudkins Robert L. 
Published: October 2006

AbstractIodocaramiphen (2) is a selective muscarinic antagonist which binds in vitro with high affinity and selectivity to the M1 subtype of the muscarinic receptor. We report the synthesis of iodine‐125 labeled iodocaramiphen ([125I]‐2) via a tributylstannyl intermediate (3) in 50% radiochemical yield with a specific activity greater than 1000 mCi/μmol. Biodistribution studies in female Fischer rats demonstrated that [125I]‐2 had significant cerebral localization (0.7% injected dose/gram) at 60 minutes post injection. The uptake of activity washed out rapidly from the brain, however, and did not demonstrate specific uptake in those cerebral regions rich in muscarinic receptors. In addition, preinjection with (±)‐QNB (5 mg/kg) blocked uptake of approximately 25% of the injected radiolabel in the brain at 2 hours. The non‐selectivity of 2 toward muscarinic receptors in vivo may result from the metabolism of 2 by various esterases or the affinity of 2 for sigma sites in the brain.
A convenient method for cyanation of aromatic iodo compounds
Authors: Carr Richard M , Cable Karl M , Wells Guy N , Sutherland Derek R 
Published: October 2006

AbstractA variety of [13C]‐labelled aromatic nitriles have been prepared in good yield from iodoaromatic substrates. Cyanation was achieved by reaction of aryl iodides with a mixture of potassium [13C]‐cyanide and copper (I) iodide in an aprotic solvent at high temperature. The use of pre‐prepared carbon‐labelled copper (I) cyanide was therefore obviated.
A facile synthesis of [15N4]‐octamethylporphyrin
Authors: Kogan Marcelo , Valasinas Aldonia 
Published: October 2006

AbstractIn order to obtain an efficient and reproducible synthesis of [15N4]‐octamethyl porphyrin for solid state CP‐MAS NMR studies, a synthesis of the outlined compound was achieved. Thus, by condensation of [15N2]‐5,5′‐dicarboxy‐3,4,3′,4′‐tetramethyldipyrrylmethane with [15N2]‐5,5′‐diformyl‐3,4,3′,4′‐tetramethyldipyrrylmethane in ethanol‐hydrochloric acid, pure [15N4]‐octamethylporphyrin was obtained in 46% yield.
Synthesis of platinum‐195m radiolabelled cis‐diammine(1,1‐cyclobutanedicarboxylato) platinum(II) of high radionuclidic purity
Authors: Kawai Kenichi , Tanaka Yoshiko , Nakano Yukihiro , Ehrlich Wilhelm , Akaboshi Mitsuhiko 
Published: October 2006

AbstractAn experimental method is described for the synthesis of 195mPt‐radiolabeled cis‐diammine(1,1‐eyclobutanedicarboxylatio) platinum(II) (carboplatin). 10 mg of 95 % enriched 194 PT was irradiated for 75 h in the hydraulic conveyer of KUR at a thermal neutron flux of approx.8.15 × 1013 n'cm−2'sec−1, and the 195mPt‐radiolabeled carboplatin was synthesized and purified using HPLC (column; C18‐ODS). The chemical yield was higher than 59.1 %, its chemical purity was greater than 99.3 %, the radionuclidic purity was nearly 100 % and the specific activity was 6.0 MBq, mg−1 carboplatin.
Synthesis of high specific activity 17α‐cyanomethyl‐17β‐hydroxy‐[14α,15α‐3H]estra‐4,9‐dien‐3‐one
Authors: Droescher P. , Röomer J. 
Published: October 2006

AbstractAn improved synthesis of the tritium labelled form of the new pharmacon DIENOGEST is described. The [14α,15α‐3‐H]DIENOGEST was obtained with a specific activity of 51 Ci/mmol and a radiochemical purity > 98%.
Preparation of n‐butoxy(13C2‐acetic) acid, 1‐n‐butoxy‐2‐hydroxy (13C2‐ethane), (n‐butoxy‐2′,2′,3′,3′,4′,4′,4′‐d7)acetic acid, and 2‐(n‐butoxy‐2′,2′,3′,3′,4′,4′,4′‐d7)ethanol
Authors: Pribish James R. 
Published: October 2006

Abstract(n‐Butoxy‐2′,2′,3′,3′,4′,4′,4′‐d7)acetic acid (1) and 2‐(n‐butoxy‐2′,2′,3′,3′,4′,4′,4′‐d7)ethanol (2) have been prepared in high yield from n‐butanol‐2,2,3,3,4,4,4‐d7. n‐ Butoxy(13C2‐acetic) acid (3) and 1‐n‐butoxy‐2‐hydroxy(13C2‐ethane) (4) have also been synthesized using bromoacetic‐13C2 acid as the source of labelled carbon. The main complication in the development of the process was partial conversion of butoxyacetic acid to butyl butoxyacetate during GC analysis, which hampered evaluation of trial reactions.
Synthesis of [2‐11C]‐6,7‐dichloro‐2,3‐dihydroxyquinoxaline and evaluation of its in in vivo distribution in rat with PET
Authors: Thorell Jan‐Olov , Stone‐Elander Sharon , Ingvar Martin , Eriksson Lars 
Published: October 2006

AbstractA method for labelling 6,7‐dichloro‐2,3‐dihydroxyquinoxaline (DCQX) in position 2 with carbon‐11 is presented. Diethyl [1‐11C]oxalate was synthesized in a two‐step, microwave‐assisted procedure from no‐carrier‐added [11C]cyanide and was reacted with 4,5‐dichloro‐1,2‐phenylenediamine in sulfuric acid at 150°C for 10 min. [2‐11C]DCQX, isolated by semi‐preparative HPLC, was > 99% radiochemically pure with a specific activity ranging between 19 ‐ 26 TBq/mmol. The total time of synthesis was 45–55 min and the isolated, decay‐corrected yields were on the order of 10%, based on the trapped [11C]cyanide. A PET study of its biodistribution after intravenous injection in a male rat revealed that the extraction of [2−11C]DCQX across the intact blood‐brain barrier was ⩽ 2%.
Synthesis of 3,5,6‐trichloropyridin‐2‐ol‐2,3,4,5,6‐13C5‐N; a metabolite of O,O‐diethyl‐O‐(3,5,6‐trichloro‐2‐pyridyl)‐phosphorothioate (chlorpyrifos)
Authors: Nomura Glenn S. , Patterson Donald G. 
Published: October 2006

AbstractA stable isotope‐labelled analog of 3,5,6‐trichloropyridin‐2‐ol has been synthesized. 3,5,6‐Trichloropyridin‐2‐ol‐2,3,4,5,6‐13C5‐15N was synthesized in a copper catalyzed cyclization from trichloroacetyl chloride‐1,2‐13C2 and acrylonitrile‐1,2,3‐13C3‐15N.
The synthesis of 3,4‐2H2‐3Z‐hexenal and 6,6,6‐2H3‐3Z‐hexenal
Authors: Fielder Simon , Rowan Daryl D. 
Published: October 2006

Abstract6,6,6‐2H3‐3Z‐Hexenal (3b) has been prepared in 89% yield and in greater than 94% purity by the oxidation of 6,6,6‐2H3‐3Z‐Hexen‐1‐ol (2b) with the Dess/Martin periodinane (1) in fluorotrichloromethane (freon 11). Use of the freon solvent greatly improved the recovery of this volatile aldehyde. Similarly the oxidation of 3,4‐2H2‐3Z‐hexen‐1‐ol (5) yielded 3,4‐2H2‐3Z‐hexenal (6) in a 92% isolated yield with a purity of greater than 99%. 3,4‐2H2‐3Z‐Hexen‐1‐ol (5) was prepared in 87% by the catalytic deuterogenation of 3‐hexyn‐1‐o1 (4) in an improved synthetic procedure.
Syntheses of colchicine and isocolchicine labelled with carbon‐11 or carbon‐13
Authors: Kothari Paresh J. , Finn Ronald D. , Larson Steven M. 
Published: October 2006

AbstractThe syntheses of isotopically labelled (−)‐10‐[11C/13C]‐colchicine and (−)‐9‐[11C/13C]‐ isocolchicine have been achieved from the reaction of (−)desmethylcolchicine with [11C/13C]‐iodomethane. The radiolabelled compounds, (−)‐10‐[11C]‐colchicine (11C‐n‐colchicine) and (−)‐9‐[11C]‐isocolchicine (11C‐i‐colchicine), were isolated by reversed phase HPLC. The total synthesis time was approximately 60 minutes for both radiolabelled compounds with an average specific activity of 240 mCi/μmol calculated to EOB. Utilizing a similar synthetic strategy, we also report the synthesis of milligram quantities of the carbon‐13 enriched compounds and the magnetic resonance signal assignment for (−)‐9‐[13C] isocolchicine.
Synthesis of 14C‐labelled hexahydro‐1,3,5‐trinitro‐1,3,5‐triazine (RDX), 2,4,6‐trinitrotoluene (TNT), nitrocellulose (NC) and glycidylazide polymer (GAP) for use in assessing the biodegradation potential of these energetic compounds
Authors: Ampleman Guy , Thiboutot Sonia , Lavigne J. , Marois A. , Hawari J. , Jones A. M. , Rho D. 
Published: October 2006

AbstractWithin the framework of an R & D project on bioremediation of soils contaminated with energetic compounds, the biodegradation of energetic products such as hexogen (RDX), trinitrotoluene (TNT), nitrocellulose (NC) and glycidyl azide polymer (GAP) is under study. Microcosm assays must be performed with radioactive carbon‐14 labelled products in order to follow the biodegradation process. 14C‐RDX was prepared by nitration of hexamethylenetetramine (HMTA) according to the Hale process. 14C‐ring and methyl labelled TNTs were synthesized according to the Dorey and Carper procedure. 14C‐cellulose was synthesized from 14C‐glucose by Acetobacter xylinum. Nitration of the 14C‐cellulose yielded 14C‐nitrocellulose. 14C‐glycidyl azide polymer was obtained by polymerization and azidation of 14C‐epichlorohydrin (ECH) which was synthesized from 14C‐glycerol. Hydrochlorination of 14C‐glycerol and epoxidation of the resulting 14C‐1,3‐dichloro 2‐propanol yielded 14C‐ECH. The syntheses of these 14C‐labelled explosives are described in this paper.
Synthesis of (1,213C)‐2‐chloroethyl phenyl sulfide
Authors: Taber Douglass F. , Wang Yanong 
Published: October 2006

AbstractIncorporation of a double 13C label into the mustard 2‐chloroethyl phenyl sulfide 2 is straightforward, but analysis is complicated by 13C‐13C coupling. An alternative is reported, in which the ease of scrambling of sulfur mustards is used to advantage to prepare precisely 50% (1, 2‐13C) enriched 2, with each carbon of the ethyl chain labelled to provide optimal signal to noise in the 13C spectrum.
A convenient method for enzymatic synthesis of radiolabelled glucose‐1,6‐bisphosphate
Authors: Nielsen Tom Hamborg , Wischmann Bente , Møller Birger Lindberg 
Published: October 2006

AbstractA convenient method to synthesize radiolabelled glucose‐1,6‐bisphosphate (Glc‐1,6‐P2) of high specific activity and in a high yield is reported. The method is based on enzymatic formation of glucose‐6‐P from glucose and ATP using hexokinase. The labelled glucose‐6‐P is then converted to Glc‐1,6‐P2 through an equilibrium reaction catalyzed by phosphoglucomutase. The two enzymatic steps and TLC separations necessary to afford radiochemically pure Glc‐1,6‐P2 can be completed in one day. The outlined experimental procedure details the synthesis of [33P]Glc‐1,6‐P2 evenly labelled at the carbon 1 and the carbon 6 position. However the commercial availability of γ‐33P and γ‐32P labelled ATP and of glucose labelled with 3H, 14C and 13C provides the option to label glucose‐1,6‐bisphosphate with any of these isotopes.
Rapid synthesis of [18F]SR46349B, a potent and selective 5‐HT2 receptor antagonist
Authors: Tan Pingzhong , Fowler Joanna S. , Ding Yu‐Shin , Schlyer David J. 
Published: October 2006

AbstractF‐18 labeled SR46349B, a highly potent and selective 5‐HT2 receptor antagonist, was synthesized as a potential radioligand for PET studies of brain 5‐HT2 receptors. Nucleophilic aromatic substitution of trans‐1‐(2‐nitrophenyl)‐3‐(4‐methoxymethoxyphenyl)‐2‐propenone (10) with NCA [18F]fluoride in the presence of potassium carbonate and kryptofix‐222, followed by HCl hydrolysis, gave F‐18 labeled 12, which was purified by a novel combination of C‐18 Sep‐Pak and silica column chromatography. Subsequent condensation of [18F]ketone 12 with Me2NCH2CH2ONH2 gave a mixture of [18F]SR46349B and its geometric isomer, which was separated by high performance liquid chromatography. The three step hot synthesis of [18F]SR46349B required 170 min. and gave a specific activity of 1140 Ci/mmol, 5% radiochemical yield (EOB) and 96% radiochemical purity.
Synthesis of labelled [13C6]testosterone and [13C5]19‐nortestosterone
Authors: Joubert Cécile , Beney Chantal , Marsura Alain , Luu‐Duc Cuong 
Published: October 2006

AbstractThe condensation of ethyl acetoacetate‐13C4 and ethyl bromoacetate‐13C2 afforded, in seven steps, (1,2,3,4,5‐13C5) 5‐(diethylphosphono)‐2‐pentanone ethylene ketal 9. The reaction of this labelled compound with 7‐[[(1,1‐dimethylethyl)‐dimethylsilyl]oxy]‐1,6,6a,7,8,9,9a, 9b‐octahydro‐6a‐methyl‐[6aS‐(6aa,7a,9aβ,9ba)] cyclopental[f][1]benzopyran‐3 (2H)‐one 13 gave the benzindenone 14 which was converted to (1,2,3,4,10,19‐13C6)testosterone 17 then, into (1,2,3,4,10‐13C5) 19‐nortestosterone 18 by a reductive alkylation method.
Synthesis of [4,6‐3H]‐2‐pyridone and [3H]‐RS‐91309
Authors: De Keczer Steve , Pames Howard 
Published: October 2006

AbstractWe describe herein, a novel synthesis of the previously unreported compound, 4,6‐dibromo‐2‐pyridone (3) and its use in the preparation of [3H]‐RS‐91309, a potassium channel modulator. This key intermediate, (3), was reduced with carrier free tritium gas to furnish [4,6‐3H]‐2‐pyridone (9) having a specific activity of 50 Ci/mmole. Condensation of (9) with epoxide (10), followed by elaboration of the resulting chromene methyl group of (12) gave [3H]‐RS‐91309 (14) whose specific activity was also 50 Ci/mmole. This chemistry, as well as the solution of several microscale related stoichiometry problems is discussed.