bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deuterium labelling of the GABA agonists THIP, piperidine‐4‐sulphonic acid and the gaba uptake inhibitor THPO
Authors: Krogsgaard‐Larsen Povl , Johansen Jørgen Stage , Falch Erik 
Published: October 2006

AbstractThe preparations of deuterium labelled THIP ([7, 7‐2H] 4, 5, 6, 7‐tetrahydroisoxazolo [5, 4‐c]pyridin‐3‐ol) (7) and THPO ([4, 4, 7‐2H] 4, 5, 6, 7‐tetrahydroisoxazo‐lo[4, 5‐c]pyridin‐3‐ol) (14) are described. [7, 7‐2H]‐THIP (7) was synthesized by triethylamine catalyzed exchange of hydrogen for deuterium in 3‐methoxy‐6‐nitroso‐4, 5, 6, 7‐tetrahydroisoxazolo [5, 4‐c] pyridine (5) using deuterium oxide, followed by acid catalyzed denitrosation and demethylation. A similar reaction sequence was employed for the preparation of [4, 4, 7‐2H]THPO (14), though the exchange reaction on the N‐nitroso intermediate 12 required strongly basic conditions. Deuterium labelled P4S (piperidine‐4‐sulphonic acid) (17) was synthesized by catalytic deuteration of pyridine‐4‐sulphonic acid (16). The structures of the deuterated compounds 6, 7, 13, 14, and 17 were established using 1H NMR spectroscopy, in the case of 17 supported by mass spectrometry.
Marquage par 35S, 14C, 3H DE LA DI [(chloro‐2 ethyl)‐2 N‐nitroso N‐ carbamoyl], N, N‐cystamine OU cncc
Authors: Madelmont J. C. , Moreau M. F. , Parry D. , Godeneche D. , Duprat J. , Meyniel G. , Oiry J. , Imbach J. L. 
Published: October 2006

AbstractDans le but de réaliser des études de disposition et de métabolisme le CNCC a été marqué par 35S, 14C, et 3H en trois positions:

‐ on the two sulfur atom of the cystamine group
‐ on the urea carbonyl
‐ on the position 1 of the 2 chloro ethyl group.
Convenient biological preparation of pure high specific activity 14C‐labelled methane
Authors: Daniels Lacy , Zeikus J. G. 
Published: October 2006

AbstractRadioactive methane of high specific activity was easily prepared using growing cultures or resuspended frozen cells of Methanobacterium thermoautotrophicum. This method gave a greater than 90% conversion of the substrate “14CO2”No distinctions are made between CO2, HCO3 − and CO3 = when the symbol “CO2” is used.
into 14CH4 using H2 as a reductant, and is also applicable to the production of 13CH4.
Evaluation of an iodination procedure for arg8‐vasopressin
Authors: Ysewijn‐van Brussel K. A. R. N. , van Steirteghem A. C. , de Leenheer A. P. 
Published: October 2006

AbstractArg8 ‐vasopressin (AVP) was labelled with iodine‐125 using chloramine‐T. The radiochemical yield of 125I‐AVP was 71% at the specific activity (S.A.) of 784 μCi/μg AVP (29 MBq/μg AVP) as estimated by self‐displacement analysis. Immunoreactivity during storage was determined by the percent binding of 125I‐ AVP with specific antiserum. Results indicate that chloramine‐T allows high iodine incorporation with limited oxidation damage. Tracers produced were found stable for at least 5 weeks.
Synthesis of deuterium labelled eumelanin (precursor) metabolites
Authors: Pavel Stanislav , Muskiet Frits A. J. 
Published: October 2006

AbstractStarting from 2,5,6‐trideutero‐3,4‐dihydroxyphenylethylamine, a mixture of 4,7‐dideutero‐5,6‐dihydroxyindole, 4,7‐dideutero‐5‐hydroxy‐6‐trideuteromethoxyindole and 4,7‐dideutero‐6‐hydroxy‐5‐trideuterometho‐ xyindole was prepared. A similar procedure for the preparation of 4,7‐dideutero‐5,6‐dihydroxyindolyl‐2‐carboxylic, 4,7‐dideutero‐5‐hydroxy‐6‐trideuteromethoxyindolyl‐2‐carboxylic and 4,7‐dideutero‐6‐hydroxy‐5‐trideuteromethoxyindolyl‐2‐carboxylic acids from methyl ester of 2,5,6‐ trideutero‐L‐3,4‐dihydroxyphenylalanine is described. The procedures are designed for the production of deuterium labelled internal standards for mass fragmentographic analysis of eumelanin (precursor) metabolites in urine. The methods can also be used for the synthesis of non‐deuterated analogs.
Synthesis of 14C‐labeled surfactants: Sodium p‐n‐dodecylbenzenesulfonate‐[phenyl‐U‐14C]
Authors: Chien David H. T. , Duncan William P. 
Published: October 2006

AbstractThe synthesis of sodium p‐n‐dodecylbenzenesulfonate‐[phenyl‐U‐14C], III, from benzene‐U‐14C is described. The preparative method consists of simple Friedel‐Crafts acylation, reduction of the resulting ketone, I, and sulfonation of II with chlorosulfonic acid. The specific activity of III was 6.8 mCi/mmole and the overall radiochemical yield was 25% (based on benzene‐U‐14C).
Synthesis of 14C‐hydroxyurea with immobilized 14C‐cyanate
Authors: Ajami Alfred M. 
Published: October 2006

AbstractA solution of hydroxylamine hydrochloride is passed over a column bed of Amberlite IRA‐400 pre‐loaded with 14CNO− anions. 14C‐hydroxyurea is formed in 50% radiochemical yield after recrystallization. The product is not contaminated with iso‐hydroxyurea or other by‐products usually found in the reaction of hydroxylamine hydrochloride with aqueous potassium cyanate.
Preparation of tritium‐labelled jasmonic acid, ethyl dihydrojasmonate and itaconic acid
Authors: Pleiß U. , Teich A. , Stock M. , Groß D. , Schütte H. R. 
Published: October 2006

AbstractA method for tritium labelling of jasmonic acid, ethyl dihydrojasmonate, and itaconic acid involving metal catalyzed hydrogen isotope exchange is described. The procedure is a convenient one‐step synthesis and specific activities in the range of 3 to 30 GBq/mmol were obtained.
Preparation of 14C‐3‐hydroxyproline from 14C‐proline by Peroxidation
Authors: Ramaswamy Sengoda G. 
Published: October 2006

AbstractConditions are described for the treatment of proline with hydrogen peroxide, ascorbic acid, and ferrous ions to produce 3‐hydroxyproline in 5–6% yield. Several reaction products are formed, but they can be separated chromatographically to yield pure trans‐3‐hydroxyproline. Synthesis of the radioactive amino acid from 14C‐L‐proline yields the pure isomer with specific activity identical to that of the starting proline. Identity of the desired product was established by chromatography, electrophoresis, and mass spectrum.
Regioselective syntheses of deuterium labelled 6‐hydroxydopamines
Authors: Simmons John , Borchardt Ronald T. 
Published: October 2006

AbstractConvenient syntheses of 2,4‐,α,α‐ and β,β‐deuterium labelled 6‐hydroxydopamines have been developed. 2,4,5‐Trimethoxybenzaldehyde (1) was reductively aminated to give 2,4,5‐trimethoxybenzylamine (2). Quaternization of the amine with methyliodide followed by displacement with cyanide gave 2,4,5‐trimethoxybenzylcyanide (4). A LiAID4 reduction of 4 gave α,α‐[2H]‐β‐(2,4,5‐trimethoxyphenyl)‐ethylamine (5). Treatment of benzylcyanide 4 with n‐butyllithium/D2O gave α,α‐[2H]‐α‐cyano‐2,4,5‐trimethoxytoluene (7) which upon reduction afforded β,β‐[2H]‐β‐(2,4,5‐trimethoxyphenyl)‐ethylamine (8). Treatment of 2,4,5‐trimethoxydimethylbenzylamine 2 with n‐butyllithium/D2O gave 3,6‐[2H]‐2,4,5‐trimethoxydimethyl‐benzylamine (10). The ring deuterium atoms were retained through subsequent steps to afford β‐(3,6‐[2H]‐2,4,5‐trimethoxyphenyl)‐ethylamine (13). Removal of the phenol protecting groups afforded the deuterium labelled 2,4,5‐trihydroxyphenethylamines (6‐hydroxydopamines).
Organopentafluorosilicates: Reagents for rapid and efficient incorporation of NO‐carrier‐added radiobromine and radioiodine
Authors: Wilbur D. S. , Svitra Z. V. 
Published: October 2006

AbstractAn investigation exploring the utility of organopentafluorosilicates as intermediates for the site specific incorporation of no‐carrier‐added radiobromine or radioiodine into organic molecules was carried out. Some simple alkyl‐ and arylpentafluorosilicates were synthesized and reacted with in situ generated [77Br]BrCl and 131 I)ICl. The radiohalogenations of aryl‐ and primary alkylpentafluorosilicates were found to be complete within 10 minutes at room temperature, with radiochemical yields of 74‐96%. Radiohalogenations of a secondary alkylpentafluorosilicate, cyclohexylSiF5 K2, gave lower radiochemical yields and required higher reaction temperatures.
Synthesis of (2S,4S)‐[5‐13C] leucine, (2R,4S)‐[5‐13C] leucine, and (2RS)‐[1,2‐13C2] leucine
Authors: Aberhart D. John , Weiller Bruce H. 
Published: October 2006

Abstract(2RS,3S)‐[4‐13C]Valine was diazotized and converted to (2RS, 3S)‐[4‐13C]‐2‐bromoisovaleric acid, which on reduction with Zn/HCl gave (3S)‐[4‐13C] isovaleric acid. This was converted to (3S)‐[4‐13C] isovaleraldehyde, which was converted by a Strecker synthesis to (2RS,4S)‐[5‐13C] leucine. Resolution via the N‐acetate then gave (2S,4S) and (2R,4S)‐[5‐13C] leucines. [1‐13C] Isovaleric acid was similarly converted to [1‐13C] isovaleraldehyde, which, in a Strecker synthesis using K13CN, gave (2RS)‐[1,2‐13C2] leucine.
The synthesis of N‐[3H] acetyl muramyl dipeptides of high specific radioactivity
Authors: Baschang G. , Brundish D. E. , Hartmann A. , Stanek J. , Wade R. 
Published: October 2006

AbstractN‐[3H]‐Acetyl‐muramyl‐L‐alanyl‐D‐isoglutamine has been synthesised by catalysed halogen/tritium exchange.
The new “one‐flask” synthesis of 14C labelled 1‐bromoalkanes ‐ synthesis of 1‐bromo [1‐14c] heptane
Authors: Elbert Tomáš , Filip Jiří 
Published: October 2006

AbstractConditions were found for almost quantitative carboxylation of n‐hexyllithium with 14CO2 to afford lithium [1‐14C] heptanoate. It was then possible to perform the reaction sequence lithium [1‐14C] heptanoate→[1‐14C] heptan‐1‐ol→ 1‐bromo [1‐14C] heptane in one flask without isolation of intermediates. In the “hot” synthesis 12,8 GBq (346 mCi) of 1‐bromo [1‐14C] heptane with radiochemical purity better than 97 % were prepared from Ba14CO3 in 81 % yield.
Synthesis of 3H‐ and 14C‐labelled astemizole (R 43 512)
Authors: Thijssen J. B. A. , Knaeps A. G. , Heykants J. J. P. 
Published: October 2006

AbstractAstemizole, a new antihistamine drug, was specifically labelled with tritium and 14C at three distinct positions. Tritium was introduced either in the 4‐methoxyphenyl (II) or in the 4‐fluorophenylmethyl (IV) moiety by catalytic dehalogenation of the corresponding halogenated analogues with tritium gas, yielding 3H‐astemizole with specific activities of 28.7 and 5.0 Ci/mmol respectively. Starting from [14C]urea, [14C]astemizole was synthesized with the label being placed in the 2‐position of the benzimidazole moiety. The radioactive yield of the three‐step synthesis was 22.4 %, spread over three fractions with specific activities of 4.5 mCi/mmol, 1.7 mCi/mmol and 0.4 mCi/mmol. The labelled compounds were radiochemically pure according to thin‐layer (TLC) and high‐performance liquid chromatography (HPLC).
The synthesis of deuterated hydroxyphenylethanolamines and their metabolites
Authors: Couch M. W. , Gabrielsen B. M. , Midgley J. M. 
Published: October 2006

AbstractThe o‐, m‐ and p‐NC [2H3] synephrines were prepared via a three step reaction from the corresponding oxazolidones. Ring deuterated msynephrine, m‐octopamine and m‐hydroxymandelic acid were prepared by [1H1] ‐ [2H1] exchange in dilute [2H1] Cl medium. Reduction of o‐ and m‐mandelic acid with lithium aluminum deuteride afforded the corresponding hydroxyphenylglycols. Exclusive side chain deuteration of 2‐dibenzyl‐1‐(4‐hydroxyphenyl)ethanone and 2‐methylamino‐1‐(3,4‐dihydroxyphenyl)ethanone were accomplished in both acidic and basic media. The former compound was deuterated on both the side chain and aromatic ring using 45% [2H1]Br.
Remote system for production of carbon‐11 labeled palmitic acid
Authors: Welch Michael J. , Dence Carmen S. , Marshall David R. , Kilbourn Michael R. 
Published: October 2006

AbstractCarbon‐11‐labeled palmitic acid is produced routinely at Washington University School of Medicine for studies ofmyocardial metabolism. To accomodate the needs of 8–15 preparations per week and the large amounts of radioactivity (>20 mCi/study) required, a remotely‐controlled system for the preparation of [1‐11C]palmitic acid has been constructed. The system is small (0.04 m3), completely portable and contained totally within a small lead‐shielded hood. Large quantities of C‐11 palmitic acid (up to 675 mCi) have been prepared, with minimum radiation exposure to the operator. This system has been in full operation for two years, and has been used for more than 200 syntheses with a failure rate of less than 5%.
Electrochemical synthesis of [131I]‐iodo‐metoprolol
Authors: Reilly R. M. , Teare F. W. , Bowent B. M. , Garnett E. S. 
Published: October 2006

AbstractUsing constant potential electro‐chemical oxidation of iodine and radioiodide in acetonitrile, a positivelycharged iodinating species, the N‐iodo‐acetonitrilium ion was produced. Electrophilic aromatic substitution of iodine through this species on the β1‐adrenergic blocking agent metoprolol resulted in the production of [131I]‐Iodo‐Metoprolol in an 82% yield.
Efficient syntheses of a variety of labeled compounds from acetylene[14C2]
Authors: Heys J. R. , Rotert G. A. , Hicks J. L. , Chew E. H. 
Published: October 2006

AbstractAcetylene[14C2] is shown to be a useful starting material for the synthesis of a number of 14C‐labeled intermediates and small molecules. Its facile preparation from inexpensive barium carbonate[14C] and the range of transformations it undergoes allow the efficient syntheses of 2‐propyn‐[2,3‐14C2]‐1‐ol, 2‐propen[2,3‐14C2]‐1‐ol, 2‐propen[G‐14C]yl‐isothiocyanate, 2‐butanone[1,2‐14C2], furan[3,4‐14C2], p‐dioxane[U‐14C], and various other intermediates.
Synthesis of 13C‐bucindolol hydrochloride
Authors: Dolak T. M. , Kreighbaum W. E. , Johnson P. C. , Covington R. R. 
Published: October 2006

Abstract[Cyano‐13C] Bucindolol hydrochloride, 2‐[2‐hydroxy‐3‐[[2‐(1H‐indol‐3‐yl)‐1, 1‐dimethylethyl]amino]propoxy]benzonitrile‐[cyano‐13C] hydrochloride, a novel beta‐adrenergic antagonist, was synthesized in our laboratory for metabolic studies. The preparation of [cyano‐13C] bucindolol hydrochloride from 2‐hydroxybenzonitrile‐[cyano‐13C] utilizing 13C‐copper(I) cyanide as an isotopic starting material is described.
One‐pot synthesis of 3‐(1‐methylethyl)‐2‐(4‐methoxyphenyl)‐3H‐naphth‐[1,2‐d] [2‐14C] imidazole
Authors: Odasso G. , Toja E. 
Published: October 2006

AbstractA one‐pot synthesis of 3‐(1‐methylethyl)‐2‐(4‐methoxyphenyl)‐3H‐naphth[1,2‐d] [2‐14C]imidazole (1), a nonacidic antiinflammatory and analgesic agent, is described. The starting material, 2‐isopropylamino‐1‐nitronaphthalene (3) was hydrogenated, the resulting diamine (4) reacted with p‐[carbonyl‐14C] anisaldehyde and the intermediate imidazoline (5) finally dehydrogenated to give (1) in a radiochemical yield of 63.4% with a radiochemical purity > 99%. The labelled compound has been used in pharmacokinetics and metabolism studies.
Synthesis of morpholinium [13C] formate and its application in the synthesis of [8‐13C] purine base
Authors: Sharma Minoti , Alderfer James L. , Box Harold C. 
Published: October 2006

AbstractMorpholinium [13C]formate is obtained by neutralizing an aqueous solution of equivalent amounts of sodium [13C]formate and hydrochloric acid with morpholine. Morpholinium [13C]formate is isolated in crystalline form and characterized. Treatment of 6‐hydroxy‐2,4,5‐triaminopyrimidine sulfate with morpholinium [13C]formate at 200° affords [8‐13C]guanine in 80% yield. There is no necessity to synthesize and isolate [13C]‐N‐formylmorpholine and the intermediate N5‐[13C]formyl pyrimidine derivative. Mass spectrometric analysis shows that the molar isotopic concentration of 13C label in guanine is identical to that of the morpholinium [13C]formate and there is no isotopic scrambling. The same procedure when used with 4,5,6‐triaminopyrimidine sulfate affords adenine in 85% yield.
A synthesis of [14C]alfuzosine hydrochloride
Authors: Allen J. 
Published: October 2006

AbstractAlfuzosine hydrochloride, N‐[3‐[(4‐amino‐6,7‐dimethoxy‐2‐quinazolinyl)‐methylamino]propyl] tetrahydro‐2‐furancarboxamide hydrochloride, labelled with carbon‐14 was synthesised in high overall yield from potassium [14C]cyanate for pharmacokinetic and metabolism studies.
Synthesis of 4,4′‐BIS([3H]methylsulphonyl)‐2,2′,5,5′‐tetrachlorobiphenyl
Authors: Klasson‐Wehler E. , Bergman A. L. , Wachtmeister C. A. 
Published: October 2006

AbstractTritium labelled 4,4′‐bis(methylsulphonyl)‐2,2′,5,5′‐tetrachlorobiphenyl with tritium in one or both methyl groups was synthesized. Sequential nucleophilic substitutions of 2,2′,4,4′,5,5′‐hexachlorobiphenyl with methane thiolate and sodium hydrogen sulphide respectively, gave 4′‐methylthio‐2,2′,5,5′‐tetrachloro‐4‐biphenylthiol which subsequently was methylated with [3H]methyl iodide and oxidized. 2,2′,5,5′‐Tetrachlorobenzidine was diazotized and coupled with potassium O‐ethyl dithiocarbonate. The product was reduced, methylated and oxidized to the sulphone with uniformly labelled methyl groups.
Facile and high yielding syntheses of phosphatidylcholines and phosphatidylethanolamines containing 2H‐labeled acyl chains
Authors: Perly B. , Dufourc Erick J. , Jarrell Harold C. 
Published: October 2006

AbstractImproved reliable methods for the partial chemical synthesis of phosphatidylcholines and phosphatidylethanolamines are described. Glycerophosphorylcholine (GPC) as its cadmium chloride complex was acylated rapidly (3 hr) with deuterated acyl anhydrides in dimethylformamide (DMF) to give phosphatidylcholines in > 90% yields. The products were free of sn‐1 and sn‐2 isomers. 2‐Lysophosphatidylcholines were rapidly acylated with acyl anhydrides, used in nearly stoichiometric amounts, in chloroform affording mixed‐chain phosphatidylcholines in > 85% yield. Pure phosphatidylethanolamines are prepared routinely in > 70% yield by an improved procedure from the corresponding phospatidylcholines using phospholipase‐D.
Labeled bile acids I: Synthesis of 18O‐methyl hydroxy‐5β‐cholan‐24‐oates
Authors: Anderson Warren G. , Byon Chang Yon , Eck Charles R. , Gut Marcel 
Published: October 2006

AbstractThe incorporation of 18O into the 3‐hydroxyl of bile acids has been accomplished by hydrolysis of the acetal corresponding to the 3‐oxo bile acid with H2O, followed by hydride reduction of the ketone to the labeled hydroxyl function.
Syntheses de l'Acide (2R, 3S); (2S, 3R) Agarique (14C‐4) et de l'Acide (2R, 3R); (2S, 3S) Agarique (3H‐4,4,5,5)
Authors: Lellouche J. P. , Beaucourt J. P. , Pichat L. 
Published: October 2006

Abstract(2R, 3S); (2S, 3R) [4‐14C] Agaric acid and (2R, 3R); (2S, 3S) [4,4,5,5‐3H] agaric acid were synthesized from respectively threo methyl 1,2‐epoxypropane‐1,2,3‐tricarboxylate 3 and erythro epoxide 2.Epoxy ring opening of 2 and 3 with [1‐14C] hexadecyl copper 10. gave respectively the analog 4 of agaric acid trimethyl ester and methyl [4‐14C]agaricate 5, which was hydrolyzed to 1a by lithium hydroxide in 1,2‐dimethoxyethane (DME).Epoxy ring trans opening of 2 with diethyl 1‐hexadecynylalane 9 gave the alcynyl derivative 7 which was saturated with tritium in presence of Pd/C to lead to 6. After hydrolysis (LiCH + DME), 1b was obtained.The structures of the diastereoisomers (2R, 3R); (2S, 3S) 1b and (2R, 3S); (2S, 3R) 1a rest on 1H‐NMR.
Labeled bile acids III: Deuterium labeled chenodeoxycholic and ursodeoxycholic acids
Authors: Lai Chee Kong , Byon Chang Yon , Gut Marcel 
Published: October 2006

AbstractSynthetic routes to some deuterium labeled bile acids are described. The conjugated methyl esters of chenodeoxycholic 15 and cholic 23 acids are the key intermediates to these syntheses.
Synthese d'un Antagoniste Alpha Adrenergique Marque au Tritium: WB 4101 [benzodioxanyl‐1,4‐3H‐2,3], ou N‐[dimethoxy‐2,6 phenoxyethyl] aminomethyl‐2 benzodioxanne‐1,4[3H‐2,3]
Authors: Guillaumet G. , Coudert G. , Ponchant M. , Beaucourt J. P. , Pichat L. 
Published: October 2006

AbstractThe synthesis of an alpha adrenergic antagonist labelled with tritium: [(2,3‐3H)‐1,4‐benzodioxanye] WB 4101 or 2‐N[2,6 dimethoxyphenoxyethye] aminomethyl 2,3‐3H‐1,4 benzodioxan is described.2‐cyano‐1,4‐benzodioxan: 1 was prepared from catechol and 2‐chloroacrylonitrille and then converted to 2‐cyano‐1,4‐benzodioxin: 2 by the successive actions of N‐bromosuccinimide in CCl4 and sodium iodide in acetone. 2 was reduced with lithium aluminium hydride into 2‐aminomethyl‐1,4‐benzodioxin: 3 and then converted to 2‐[N‐(2,6‐dimethoxyphenoxyethyl)‐aminomethyl]‐1,4‐benzodioxin: 4a, and its hydrochloride: 4b.The catalytic reduction of 4a, 4b with tritium in various and in presence of various catalysts was studied. The best result was obtained with Wilkinson's catalyst in benzene giving rise to [(2,3‐3H)1,4‐benzodioxanyl]WB 4101 with a specific activity of 60 CilmMole. 3H.NMR and MS analyses are also described.
Synthesis of tritiated bumetanide
Authors: Wyrick Steven D. , Morris‐Natschke Susan , Lauf Peter K. 
Published: October 2006

AbstractTritium Iabelled bumetanide of high specific activity (16 Ci/mmol) has been prepared in our laboratory by tris(triphenyl‐phosphine) rhodium chloride catalyzed reduction of an olefinic precursor with carrier free tritium gas in benzene‐ethanol (1:1). The product is labelled in the N‐butyl side chain. Comparison of both heterogeneous palladium and homogeneous rhodium catalyzed deuterium reductions as a model for the tritiation revealed that the latter reduction was accompanied by considerably less label scrambling.
Enzymatic synthesis of 11C‐labelled (−)‐epinephrine
Authors: Soussain Robert , Gueguen Paul , Morgat Jean‐Louis , Maziere Mariannick , Berger Gérard , Comar Dominique 
Published: October 2006

AbstractAn enzymatic method is described for the synthesis of 11C‐labelled (−)‐epinephrine in which the [11C]methyl group is sequencially transferred from L‐[methyl‐11C]methionine to (−)‐norepinephrine via S‐adenosyl‐L‐[methyl‐11C]methionine respectively by the enzymes L‐methionine‐S‐adenosine transferase (M.A.T) and phenylethanolamine‐N‐methyl transferase (P.N.M.T). Chromatographically pure 11C‐epinephrine having a specific activity approximately 200 Ci/mmol is obtained 35 minutes after the synthesis of the starting compound L‐[methyl‐11C]methionine.Preliminary results are presented for the dynamics of the distribution of the 11C‐epinephrine in organs of the rabbit by gamma scintigraphy.
Synthesis of tetrachloroisophthalo‐[14C]‐nitrile
Authors: Davies Peter E. 
Published: October 2006

AbstractA low cost, high yield synthesis of tetrachloroisophthalo‐[14C]‐nitrile (TCIN) is described. Direct replacement of iodine in 3‐iodobenzonitrile using 14C‐labeled cuprous cyanide, and vapour phase chlorination yields [14C]‐TCIN, with maximum utilisation of the radiolabel. Alternative and unsuccessful routes are also briefly described.
Electrophilic radiobrominations of hippuric acid: An example of the utility of aryltrimethylsilane intermediates
Authors: Wilbur D. S. , Svitra Z. V. 
Published: October 2006

AbstractAn investigation of the use of an aryltrimethylsilane intermediate to obtain p‐[77Br]bromohippuric acid (12) was carried out. The silane intermediate, p‐trimethylsilylhippuric acid (11), was radiobrominated with carrier‐added and no‐carrier‐added levels of bromine‐77 to give isolated yields of 73% and 49% of 12 (respectively). Initial radiobromination studies were carried out with p‐trimethylsilylbenzoic acid (1) to evaluate the feasability of the approach. Radiobrominations of 1 yielded 70–93% radiolabeling efficiencies. All of the radiobrominations could be accomplished within 15 minutes, indicating that the method could be applicable to use of the shorter lived radionuclides of bromine.
Synthesis of 14C‐ochratoxin A
Authors: Rousseau D. , Slegers G. , Van Peteghem C. , Claeys A. 
Published: October 2006

Abstract14C‐Ochratoxin A is obtained by coupling the N‐hydroxy‐succinimide derivative of the lactone acid hydrolysate of natural ochratoxin A with 14C‐L‐β‐phenylalanine methylester. 14C‐Ochratoxin A methylester is converted into 14C‐ochratoxin A by alkaline hydrolysis. Purification of the intermediates and the 14C‐ochratoxin A is achieved by HPLC. For an amount of 0.05 μmole L‐β‐phenylalanine methylester the yield of ochratoxin A is 0.02 μmole or 40% and the specific activity 130 Ci/mole. Stereospecificity is 100% and radiochemical purity is 96%.The yield of 14C‐ochratoxin A increases with increasing amounts of 14C‐L‐β‐phenylalanine methylester and reaches 80% under the best conditions.