bluuebunny/crossref_metadata_2025 huggingface dataset:
Organopentafluorosilicates: Reagents for rapid and efficient incorporation of NO‐carrier‐added radiobromine and radioiodine
Authors: Wilbur D. S. , Svitra Z. V.
Published: October 2006

An 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

(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

N‐[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

Conditions 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.
An improved procedure for the synthesis of [18O]sulfoxides
Authors: Okruszek Andrzej
Published: October 2006

[18O]Sulfoxides are prepared in high yield with no loss of isotope enrichment by one‐step sulfide oxidation with CH2Cl2/Br2/H218O/pyridine.
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

Astemizole, 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

The 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

Carbon‐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

Using 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

Acetylene[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

[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

A 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

Morpholinium [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

Alfuzosine 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 3H labeled rifamycin L 105
Authors: Cellai L. , Colosimo M. , Marchi E.
Published: October 2006

3H labeled rifamycin L 105, a potential new intestinal disinfectant, was synthesized according to the Wilzbach method with the aim of performing radiopharmacological 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

Tritium 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

Improved 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

The 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

(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

Synthetic 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

The 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

Tritium 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

An 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

A 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

An 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

14C‐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.
Multi‐13C‐labelled 2,4‐diamino‐6‐methylpteridine
Authors: Cheung H. T. A. , Gray P. G.
Published: October 2006

Samples of 2,4‐diamino‐6‐methylpteridine (1), specifically labelled with 13C at one or more carbon positions, were synthesised using a combination of the appropriate unlabelled and the following 13C‐labelled starting materials (ca. 90% 13C): acetone‐2‐13C, acetone‐1,3‐13C, bromoacetic acid‐1‐13C, bromoacetic acid‐2‐13C, sodium cyanide‐13C, and guanidine‐13C. The identity and site(s) of 13C of each final product and intermediate were established by 13C‐and 1H‐NMR.
Synthesis of carbon‐14 and carbon‐13 labeled 3‐methyl‐6‐[3‐(trifluoro‐methyl)phenyl]‐1,2,4‐triazolo[4,3‐b]pyridazine
Authors: May M. K. , Lanzilotti A. E.
Published: October 2006

3‐Methyl‐6‐[3‐(trifluoromethyl)phenyl]‐1,2,4‐triazolo[4,3‐b] pyridazine (4), currently being evaluated as a potential anxiolytic agent was synthesized, labeled with carbon‐14 in the 3‐position of the triazolo nucleus. The product was obtained in 67% radiochemical yield with specific activity of 13.5 mCi/mmol and radiopurity of greater than 99%. The carbon‐13 labeled compound was also synthesized for absorption and metabolism studies.
Synthesis of stabilized tritium‐labelled 1, 3‐dioxa‐2‐hydroxypropane derivatives for use as lymphatic absorption adjuvants
Authors: Saljoughian Manouchehr
Published: October 2006

The synthesis of stabilized tritium‐labelled 2‐monoglycerides which may be used as lymphatic absorption adjuvants, using [carbonyl‐3H]‐benzaldehyde is described. A simple method of analysis for the regeneration of these compounds from their stabilized forms is also proposed.
Synthesis of L‐[4,4‐2H2] and D,L‐[3,3,4,4‐2H4] methionine
Authors: Ramalingara Kondareddiar , Woodard Ronald W.
Published: October 2006

The syntheses of D,L‐[3,3,4,4‐2H4]methionine from [2,2,2‐2H3] acetic acid in seven steps in an overall yield of 26% and L‐[4,4‐2H2]methionine from N‐t‐BOC‐L‐aspartic acid α‐benzyl ester in five steps in an overall yield of 40% are described.
Synthesis of tritium‐labelled phosphonium choline
Authors: Sim Edith
Published: October 2006

Tritium‐labeled phosphonium choline chloride ([2‐hydroxyethyl] trimethyl phosphonium chloride) has been synthesized using base‐catalyzed hydrogen exchange of the hydrogen atoms attached to the carbon adjacent to the phosphonium phosphorus. Using 3H2O diluted in 2H2O, during the exchange reaction, it is shown by proton‐NMR that substitution of the methylene protons is almost complete when only 25% of the methyl protons have exchanged. Comparison of the measured specific activity (16.12mCi/mmol) with that calculated from the total proton exchange values shows that there is a large isotope effect favouring exchange to deuterium rather than tritium.
Labeled bile acids IV: Base‐catalyzed one‐pot synthesis of deuterium labeled bile acids
Authors: Lai Chee Kong , Byon Chang Yon , Gut Marcel , Nagahisa Atsushi
Published: October 2006

Deuterium labeled bile acids are synthesized from their keto acid analogs by a one‐pot base‐catalyzed enolization exchange with deuterated hydroxylic solvents (OD) followed by in situ reduction of the ketone. The stereochemistry of the alcohol, especially that at C‐7, can be controlled either by steric approach reduction with sodium borodeuteride or thermodynamically by reduction with sodium in n‐butanol.
Synthesis of hexadeuterated diethylstilbestrol (E‐3,4‐DI‐(4‐hydroxyphenyl) hex‐3‐ene‐1,1,1,6,6,6‐2H6)
Authors: De Clercq P. J. , Van Peteghem C. H. , Jonckheere J. A. , De Leenheer A. P.
Published: October 2006

We describe the synthesis of deuterated diethylstilbestrol isotopomers, starting from commercially available ketones. Attempts to synthesize E‐3,4‐di‐(4‐hydroxyphenyl) hex‐3‐ene‐2,2,5,5‐2H4 from 4‐methoxypropiophenone were not successful. Starting from 4‐methoxyacetophenone, isotopically pure E‐3,4‐di‐(4‐hydroxyphenyl)hex‐3‐ene‐1,1,1,6,6,6‐2H6 was obtained. The 3‐steps synthesis involved alkylation of the ketone with iodomethane‐1,1,1‐2H3, reductive coupling with titanium trichloride‐lithium reagent, and demethylation with trimethylsilyliodide. The possible use of the hexadeuterated diethylstilbestrol in isotope dilution mass spectrometry is demonstrated.
Tritium labelled 2‐trifluoroacetamidobenzenesulfonyl fluoride
Authors: Wyrick Steven D. , Mitchell John A. , Ranga V.
Published: October 2006

Here, we report the synthesis of high specific activity tritiated 2‐trifluoroacetamidobenzenesulfonyl fluoridea potent elastase inhibitor. Preparation of a ring iodinated precursor followed by palladium on CaCO3 catalyzed deiodination with deuterium and tritium gas afforded high levels of isotope incorporation in both cases.
Facile synthesis of [4‐13C] butanoic acid and [4‐13C] butanol
Authors: Van Der Laan R. , Moolenaar M. J. , De Koning H.
Published: October 2006

Alkylation of the dianion of 3‐(phenylsulfinyl) propanol with [13C] iodomethane and subsequent reductive fission of the sulfoxides gave [4‐13C] butanol that was oxidized to give [4‐13C] butanoic acid.
Synthesis of the epimeric 2‐bromocholesterols and their conversion into (2α‐3H)cholesterol and [2ß‐3H]cholesterol
Authors: Römer J. , Wagner H. , Ponsold K.
Published: October 2006

The synthesis of the epimeric 2‐bromocholesterols is described. Their reductive catalyzed debromination with T2 affords [2α‐3H]‐ and [2ß‐3H]cholesterol respectively. The [2‐3H] cholesterols can be synthesised with a radiochemical purity >98% and specific activities of about 600–700 GBq/mmol. The labelling reactions proceed under retention.
An evaluation of the introduction of stable nuclides of bromine into high specific activity radiobrominations
Authors: Wilbur D. S. , Garcia S. R. , Adam M. J. , Ruth T. J.
Published: October 2006

An investigation has been carried out to evaluate the quantity of stable nuclides of bromine that might be introduced into the reaction mixtures of high specific activity radiobrominations from the reagents used. In the investigation neutron activation analyses were performed on the radionuclide solutions, solvents, oxidizing agents, and substrates that have been used in radiobromination reactions to determine the concentrations of bromine present. All of the reagents examined had detectable quantities of bromine. Among the reagents, a large variation in the concentrations of bromine was found. Due to the quantities of bromine found and the variability of bromine concentrations in the reagents, it is suggested that the reagents used in high specific activity radiobrominations be analyzed for bromine.
Synthesis of 1‐decene‐2‐13C
Authors: Marchand Alan P. , Kaya Riza
Published: October 2006

A four‐step synthesis of 1‐decene‐2‐13C starting with 1‐bronooctane (57% overall yield) is described.
Synthesis of deuterium‐labeled 1‐aminocyclopropane‐1‐carboxylic acid
Authors: Ramalingam Kondareddiar , Kalvin Douglas , Woodard Ronald W.
Published: October 2006

The syntheses of D,L‐1‐amino[2,2‐2H2]cyclopropane‐1‐carboxylic acid; 1‐amino [c‐2,c‐3‐2H2] and 1‐amino[t‐2,t‐3‐2H2]cyclopropane‐1‐carboxylic acid (cis‐[2H2]ACC); 1‐amino[2S,3S‐2H2] and 1‐amino[2R,3R‐2H2]cyclopropane‐1‐carboxylic acid (trans‐[2H2]ACC); and 1‐amino[2,2,3,3‐2H4]cyclopropane‐1‐carboxylic acid are described. The [2,2‐2H2]and [2,2,3,3‐2H4]ACC compounds were prepared from the appropriately deuterated 2‐bromoethanol 4‐methylbenzenesulfonates by reaction with ethyl isocyanoacetate and two moles of sodium hydride. The trans‐[2H2]ACC and cis[2H2]ACC were prepared from meso and d, l‐[1,2‐2H2]‐1,2‐dibromoethane respectively, by reaction with ethyl isocyanoacetate and two moles of sodium hydride. These compounds are required for use in the study of the biosynthesis of ethylene by various plants and for use in 1H and 13C‐NMR studies of 1‐aminocyclopropane‐1‐carboxylic acid derivatives.
Synthesis of deuterium labelled clofibrate
Authors: Saljoughian Manouchehr
Published: October 2006

The synthesis of deuterium labelled clofibrate using fully deuterated acetone, (CD3)2 CO, as labelling agent is described. Purification of labelled material was accomplished by recrystallization and fractional distillation.
Comparison of tritiation efficiency using 3H3+ and 3H2+ ion beams
Authors: Richardson B. C. , Kam Chih‐Min , Powers J. C. , Moran T. F.
Published: October 2006

A new apparatus was constructed to tritiate biological molecules using mass analysed tritium ion beams. The magnetic sector of this device was constructed of high field Sm‐Co permanent magnets. Mass analyzed ions of desired kinetic energy were impacted on an involatile solid and 3H exchanged for H. The 3H2+ ions were found to be more reactive than 3H2+ ions. The sensitive peptide aldehyde leupeptin was utilized to test the efficacy of mass analyzed ion beam tritiation and leupeptin was not decomposed by this process.
Preparation of tritium‐labelled meta‐aminolevamisole of high specific radioactivity by catalytic dehalogenation
Authors: Lewis James A. , Paterson Ian
Published: October 2006

We describe the synthesis of tritiated meta‐aminolevamisole (MAL) of high specific radioactivity. Unlabelled MAL was iodinated with iodine monochloride in aqueous hydrochloric acid. The major reaction product, L[‐]2,3,5,6‐tetrahydro‐6‐(5‐amino‐2‐iodophenyl)imidazo [2,1‐b]thiazole, was catalytically dehalogenated with carrier‐free tritium gas in methanolic potassium hydroxide over 10% palladium‐carbon. After extraction and chromatography, a radioactive species ([3 H]‐MAL) was identified with the same chromatographic mobility as unlabelled MAL, [3 H]‐MAL possesses the same high biological activity in contracting nematode muscle as authentic unlabelled MAL, co‐chromatographs with unlabelled MAL in three different TLC systems and is about 90% radiochemically pure. By bioassay and competitive inhibition studies, the specific radioactivity of [3 H]‐MAL appears greater than 15 Ci/mmole and is probably close to 29 Ci/mmole. [3 H]‐MAL was shown to be useful for detecting a high affinity, saturable binding activity in extracts of the nematode Caenorhabditis elegans.
Synthesis of N‐(11C) methyl, N‐(methyl‐1 propyl), (chloro‐2 phenyl)‐1 isoquinoleine carboxamide‐3 (PK 11195): A new ligand for peripheral benzodiazepine receptors
Authors: Camsonne R , Crouzel C , Comar D , Mazière M , Prenant C , Sastre J , Moulin Ma , Syrota A
Published: October 2006

N‐(11c) methyl, N‐(methyl‐1 propyl), (chloro‐2 phenyl)‐1 isoquinoleine carboxamide‐3 (PK 11195) or (11C) MPCI was synthetized in a short time (45 min) and high specific activity (769 Ci/mmo 1) for the positron emission tomography of peripheral benzodiazepine receptors in heart, kidney and brain. The precursor used was the N‐desmethyl MPCI (PCI). The radioactive reagent was the (11C) methyl iodide obtained from nuclear reaction 14N (p, α) 11C via 11CO2 and 11CH3OH. The chemical purity of the end‐product was checked, after HPLC purification, by chemical ionisation mass spectrometry in the parallel synthesis of cold MPCI. The methylation, reversed phase HPLC purification, evaporation times were 10, 6 min respectively so that sterile and isotonic injectable solution of (11C) MPCI ready for use may be obtained, in less than 45 min after the end of nuclear bombardment.
Synthesis of 3‐[3H]‐5‐(4′‐azobenzene arsonic acid)‐L‐tyrosine
Authors: Brundish D. E. , Wade R.
Published: October 2006

The title compound (ABA‐Tyr) was prepared by direct radiochemical synthesis from tritiated tert.‐butoxycarbonyl‐L‐tyrosine and diazotised arsanilic acid followed by acidolytic deprotection and isolation by preparative high pressure liquid chromatography. The product had a specific activity of 9 Ci mmol−1 and a radiochemical purity of 90–95%.
Synthesis of labelled nordihydroguaiaretic acid
Authors: Chan Carrie Y.‐C. , Leaffer M. A. , Parkhurst R. M. , Thomas D. W. , Allen L. M. , Jordan R. T. , Pardini R. S.
Published: October 2006

Meso‐2,3‐Dimethyl‐1,4‐bis(3,4‐dihydroxyphenyl)bytane‐1‐14C, (mesonordihydroguaiaretic acid‐1‐14C, NDGA‐1‐14C), was prepared. meso‐2,3‐Dimethyl‐1‐1,4‐bis (3,4‐dihydroxy‐2,5,6‐trideuterophenyl)butane (NDGA‐d6, ring labelled) was made from acid exchange of unlabelled natural product and meso 2,3‐dimethyl‐1,4‐bis(3,4‐dihydroxyphenyl)‐1,1,2,3,4,4‐hexadeuterobutane (NDGA‐d6, chain labelled) was prepared from hydrogenation of 3,4‐dimethyl‐2,5‐bis‐(3, 4‐dimethoxyphenyl)furan using deuterium and Pd/C catalyst.
Resolution of [11C]DL‐leucine and [11C]DL‐tryptophan by high‐performance liouid chromatography
Authors: Washburn Lee C. , Sun Tan Tan , Byrd Billy L. , Callahan Alvin P.
Published: October 2006

High‐performance liquid chromatographic (HPLC) resolution of [11C]DL‐leucine and [11C]DL‐tryptophan, using modifications of a previously developed technique for resolution of [11C]DL‐valine, was used to produce [11C]L‐leucine and [11C]L‐tryptophan. The technique employs commercially available reverse phase HPLC columns and chiral mobile phases containing cupric acetate and L‐proline.
Synthesis and tritium labeling of the food mutagens IQ and methyl‐IQ
Authors: Waterhouse Andrew L. , Rapoport Henry
Published: October 2006

The mutagens found in cooked meat, 2‐amino‐3‐methylimidazo[4,5‐f]‐quinoline (IQ) and 2‐amino‐3,4‐dimethylimidazo[4,5‐f]quinoline (Methyl ‐ IQ), have been synthesized by unambiguous methods that allow for the preparation of sufficient quantities of material for biological studies. These methods avoid difficult separations of regioisomeric mixtures of products and incorporate specific high level tritium, labeling, effected by hydrogenolysis of the appropriately substituted 5‐bromo precursors.
Total synthesis of (1‐13C)‐glycerol
Authors: Barber Jill
Published: October 2006

A simple, inexpensive synthesis of (1‐13C)‐glycerol is described.
Generation of [75Se]dimethyl selenide and the synthesis of [75Se]dimethyleselenonium compounds
Authors: Foster Stephen J. , Kraus Richard J. , Ganther Howard E.
Published: October 2006

The synthesis of various [75Se]selenonium compounds of biological interest is described. [75Se]Trimethylselenonium iodide (sp. Ac. 32 mCi/mmol), prepared from commercially available [75Se]selenocystine (Foster S. J. and Ganther H. E. ‐ Anal. Biochem. 137: 205–9, 1984.) was decomposed thermally, in a stream of nitrogen, to give [75Se]dimethyl selenide, which was trapped in nitromethane at −18°C. [75Se]Dimethyl selenide was reacted, in nitromethane solution, with various alkyl halides to give dimethylselenonium compounds of the type (CH3)2Se+‐R, where R = CH2CO2H, CH2H, CH2CO2C2H5, ‐(CH2)2CO2H and ‐(CH2)2CO2C2H5. [75Se]Methyl‐selenomethionine‐selenonium iodide was synthesized from [75Se]selenomethionine and methyl iodide in a mixture of formic and acetic acids at 25°C. [75Se]Selenocystine was reduced and methylated to give [75Se]‐methylselenocysteine, which was slowly converted to [75Se]dimethyl‐selenocysteineselenonium iodide by the same reaction.
Synthesis of tritium labeled nadolol
Authors: Oatis John E. , Eller T. D. , Knapp D. R.
Published: October 2006

Tritium labeled nadolol (3) was prepared by electrophilic bromination of nadolol (1) to give 8′‐bromonadolol (2). Catalytic reductive debromination with tritium gas gave 8′‐[3H]‐nadolol (3), with a specific activity of 3.36 Ci/mmol.
Preparation of 14C‐labelled AMP, ADP AND ATP from adenine‐8‐14C by using brevibacterium ammoniagenes
Authors: Pande V. N.
Published: October 2006

High radiochemical yields of 14C‐labeled adenine nucleotides (AMP, 4.6%; ADP, 15.5% and ATP, 59.5%) could be obtained by growing the cells of Brevi bacterium ammoniaqenes in the presence of 14C‐adenine. The specific radioactivity of the adenine nucleotides almost reached that of 14C‐adenine indicating negligible dilution of the label. The procedure is conveninet and especially suited for commercial preparation of the radiolabeled nucleotides directly from labeled adenine. Preliminary results indicate that the organism could also be used for the preparation of radiolabeled quanine nucleotides.
Synthesis of N‐[3‐OXO‐(4,5‐3H2)‐hexanoyl] homoserine lactone: Biologically active tritium‐labelled vibrio fischeri autinducer
Authors: Kaplan H. B. , Eberhard A. , Widrig C. , Greenberg E. P.
Published: October 2006

N‐(3‐oxo‐4‐hexenoyl) homoserine lactone was synthesized and then reduced with Wilkinson's catalyst in the presence of tritium gas to form N‐[3‐oxo‐(4,5‐3H2)‐hexanoyl] homoserine locatone (45–55 Ci/mmol). The labelled compound was indistinguishable from the autoinducer for Vibrio fischeri luciferase [N‐(3‐oxohexanoyl) homosernine lactone] by high‐performance liquid chromatography and it was biologically active.
Production of 11C‐labeled quinidine and tamoxifen
Authors: Van Haver D. , Vandewalle T. , Slegers G. , Vandecasteele C.
Published: October 2006

The production of [11C] quinidine and [11C] tamoxifen for use with positron emission tomography is described. The potassium salt of O‐desmethylquinidine and N‐desmethyltamoxifen free base are treated with [11C]methyl iodide at 130°C for 10 min. After HPLC separation, the [11C‐methyl]‐labeled compounds are produced with a radiochemical yield of 60 and 70 % respectively. Injectable activities from 50 to 70 mCi are obtained 1 h after the irradiation; the specific activity is 40–60 mCi/μ mole. The entire production is controlled by a microprocessor.
Synthesis of O‐ and P‐fluoro‐α‐methylstyrenes labelled with carbon‐14 in the side chain
Authors: Ali H. M. , Barson C. A. , Coe P. L.
Published: October 2006

Ortho‐ and para‐fluoro‐α‐methylstyrenes specifically 14C‐labelled in all three positions of the side chain have been synthesized by a modified Wittig reaction. The appropriate acetophenones were synthesized as intermediates. The yields in all cases were good and any radiochemical impurities could be readily removed by careful fractional distillation.
Synthesis of (+) and (−) [10‐14C]‐α‐ and β‐pinenes
Authors: Njar Vincent C. O. , Banthorpe Derek V.
Published: October 2006

[10‐14C]‐(+) and (−)‐β‐Pinenes were prepared from their corresponding non‐radioactive isomers by the Wittig reaction; and the [10‐14C]‐ (+) and (−)‐α‐isomers were obtained from the [10‐14C] ‐β‐pinenes by isomerization. After purification by gas chromatography the specific activity for each of the isomers was ca. 0.025 mCimmol−1, and all the isomers had high (>90%) optical purities. All four isomers were found to be chemically (>99.5%) and radiochemically (>99.5%) pure.
Regioselective labelling of anilides with deuterium
Authors: Lockley W J S
Published: October 2006

N‐Aryl amides may be deuterated by exchange with deuterium oxide in the presence of rhodium (III) chloride. Under such conditions deuterium is introduced into positions ortho to the anilide nitrogen atom with a high degree of regioselectivity.
The use of boron tribromide as a catalyst for the rapid tritium labeling of aromatic compounds
Authors: Garnett John L. , Long Mervyn A. , Lukey Christopher A.
Published: October 2006

Boron tribromide has been assessed as a catalyst for rapid tritium labeling of organic compounds using tritiated water under mild conditions. Alkyl and halogen substituted aromatics labeled rapidly, the labeling being most pronounced in the ortho and para positions. Compounds containing electrophilic deactivating groups were found to be difficult to label. Very little byproduct formation was observed.
The syntheses of no‐carrier‐added and carrier‐added 18F‐labelled haloperidol
Authors: Farrokhzad Simin , Diksic Mirko
Published: October 2006

Fluorine‐18 labelled haloperidol (18F‐HP) was synthesized by a fluorine‐fluorine exchange reaction on haloperidol, fluorine‐chlorine exchange on a chloro‐analog of haloperidol, and from 18F‐labelled p‐fluorobenzonitrile prepared by two different exchange reactions. Nucleophilic fluorine was used in the form of tetra n‐butylammonium fluoride. The overall radiochemical yield, expressed at the end of syntheses was 5% for exchange in haloperidol and about 2%‐3% for exchange in chloroanalog in a 40 min synthesis (from the end of the irradiation). Specific activity up to 1 Ci/mmol for haloperidol and up to 5000 Ci/mmol for chloro‐analog as substrates were obtained. The syntheses using p‐substituted chloro‐and nitro‐benzonitriles as starting materials for the exchange reaction gave a product with an average specific activity of about 2000 Ci/mmol and in general an overall radiochemical yield of 5%–10%. Purification of [18F]haloperidol was done by HPLC on a C‐18 column. The radiochemical purity as assessed by thin layer radiochromatography (TLRC) of the final product was at least 95%, with high chemical purity.
Synthese des Metabolites de L'Insecticide Deltamethrine : Acides Phenoxy‐3 Benzoiques (carboxyle 14C), Alcools Phenoxy‐3 Benzyiques (hydroxyméthyle 14C)
Authors: Do‐Cao‐Thang  , Nguyen‐Hoang‐Nam  , Hoellinger H. , Pichat L.
Published: October 2006

Procedures are described for the synthesis of the following metabolites of deltamethrin, the pyrethroid insecticide: 3‐phenoxy (carboxyl‐14C) benzoic acid, 3‐(2′‐hydroxyphenoxy) (carboxyl‐14C) benzoic acid and the corresponding 3‐phenoxybenzyl alcohols, specific activity = 47–57 mCi/mmol.
The synthesis of spiromustine ‐d8. A general approach to octadeuterated nitrogen mustards
Authors: Huguenin Philipp N. , Kelley James A.
Published: October 2006

The synthesis of deuterium labelled spiromustine, a potential new antitumor agent designed specifically for neoplasms of the central nervous system, is described. Eight deuterium atoms have been incorporated specifically into the nitrogen mustard moiety to provide a deuterated internal standard suitable for selected ion monitoring by GC/MS. Starting with ethylene glycol‐d6, diethanolamine‐d8 is produced efficiently in good yield with no deuterium exchange via a 2‐imino‐1,3‐oxazolidine intermediate. The resultant diethanolamine‐d8 may then be used to synthesize spiromustine‐d8 or other octadeuterated nitrogen mustards.
Synthesis of 13C single and double labelled retinals, precursors for NMR studies of visual pigments and related systems
Authors: Iqbal M. , Copan W. G. , Muccio D. D. , Mateescu G. D.
Published: October 2006

The synthesis of retinals enriched with 13C at positions 11, 13, 14, 15, 12&20, 13&14, and 14&15 in high isomeric purity is reported. The importance of these retinals in studying the structure and properties of rhodopsin and bacteriorhodopsin by 13C NMR spectroscopy is briefly described.
Synthesis of a new class of retinoid, 3H‐labelled TTNPB, 1 with a high specific activity
Authors: Rhee Sung W. , Degraw Joseph I. , Kaegi Heinz H.
Published: October 2006

Synthetic procedures for tritiation of a retinodal benzoic acid derivative, (E)‐4‐[2‐(5,6,7,8‐tetrahydro‐5,5,8,8‐tetramethyl‐2‐naphthalenyl‐6,7‐ 3H2)‐1‐propenyl]‐benzoic acid, (TTNPB), are described. Tritium was introduced by catalytic hydrogenation. The final product, TTNPB‐3H2 (9), had a specific activity of 24.1 Ci/mmole and a radiochemical purity of 95.6%.
Utilisation de L'Ethanolamine14C Comme Precurseur 1ère Partie : Marquage de la N'‐(Chloro‐2 Ethyl) N‐[(Methyl Sulfinyl)‐2 Ethyl] N'‐Nitrosouree et de la N'‐(Chloro‐2 Ethyl) N‐[(Methyl Sulfonyl)‐2 Ethyl] N'‐Nitrosouree Par 14C
Authors: Madelmont J. C. , Parry D. , Godeneche D. , Duprat J.
Published: October 2006

Deux nouvelles chloro 2 ethyl nitrosourées ont été marquées en deux positions par le 14C ` partir de Nal14CN en utilisant l'éthanolanine 14C comméinter:

‐ sur le carbone 2 du groupe chloro 2 ethyl

‐ sur le carbone 2 de la partie cystéarnine.
Synthesis of nedocromil sodium labelled with tritium, deuterium and carbon‐14
Authors: Wilkinson D J , Lockley W J S
Published: October 2006

Nedocromil sodium labelled with carbon‐14 has been prepared by a Claisen reaction between diethyl [1,2‐14C]‐ethanedioate and methyl 6‐ethanoyl‐1‐ethyl‐1,4‐dihydro‐7‐hydroxy‐4‐oxo‐8‐propylquinoline‐2‐carboxylate. The 2H‐ and 3H‐labelled materials are readily prepared by rhodium(III) chloride catalysed exchange with the appropriate isotopically labelled water.
Synthesis of specifically‐labelled tritiated benzimidazole carbamates
Authors: Lacey E.
Published: October 2006

Benzimidazole carbamates are thought to exert their biological activity as anthelmintics by binding to helminth tubulin. To investigate this hypothesis, the synthesis of two specifically‐labeled tritiated benzimidazoles, parbendazole and oxibendazole, has been accomplished. These labels were prepared by debromination of the appropriate 5‐bromo analogue using sodium borotritide in the presence of palladium chloride. The brominated derivatives were synthesized by the bromination of the benzimidazole using bromine in glacial acetic acid.
Stereospecific synthesis of L‐[1,4‐13C2]aspartic acid, L‐β‐([13C]cyano)alanine and L‐[4‐13C]aspartic acid
Authors: Röhm Klaus H. , van Etten Robert L.
Published: October 2006

A convenient stereospecific synthesis of L‐aspartic acid, 13C‐labelled in both carboxyls, is described. The crucial step of the procedure is the conversion of [1,4‐13C2]fumaric acid to L‐aspartic acid utilizing the enzyme L‐aspartase. In addition, an improved synthesis of L‐β([13C]cyano)alanine was developed. This compound is easily converted to L‐[4‐13C]aspartic acid.
Preparation of [4‐3H]‐3‐dehydroretinol by sodium borotritide reduction
Authors: Tosukhowong Pichit , Supasiri Thararat
Published: October 2006

[4‐3H]‐Dehydroretinol (5) was prepared from a vitamin A derivative. The procedure involves conversion of methyl retinoate (1) to methyl 4‐oxoretinoate (2) by manganes dioxide oxidation. The 3H‐label was introduced by sodium borotritide reduction of methyl 4‐oxoretinoate (2) followed by acid catalyzed dehyration to methyl [4‐3H]‐3‐dehydroretinoate (4). Reduction of the tritiated methyl dehydroretinoate with lithium aluminium hydride yielded [4‐3H]‐3‐dehydroretinol (5). Final purification was achieved by preparative thin layer chromatography.
Preparation of 14C‐ and 18O‐labeled 2‐[2‐methoxy‐4‐(methylsulfinyl)phenyl]‐1H‐imidazo[4,5‐c]‐pyridine hydrochloride (LY175326), a cardiotonic with inotropic and vasodilator activities
Authors: Kau Don , Krushinski Joseph H. , Robertson David W.
Published: October 2006

Two different forms of 14C‐labeled 2‐methoxy‐4‐(methylthio) benzoic acid were prepared and employed in the synthesis of 14C‐labeled 2‐[2‐methoxy‐4‐(methylsulfinylphenyl]‐lH‐imidazo‐[4,5‐c]pyridine hydrochloride (LY175326), a cardiotonic with inotropic and vasodilator activities that is currently in clinical trials. The synthetic procedures described in this report allowed the introduction of the 14C‐label in the antepenultimate step. Additionally, an 18O‐labeled form of LY175326 was synthesized to facilitate kinetic analysis of the formation of its sulfide and sulfone metabolites.
Synthesis of 6‐(10‐hydroxy‐[1‐14C]decyl) ‐2,3‐dimethoxy‐5‐methyl‐1,4‐benzoquinone
Authors: Hayashi Nobuyoshi , Kato Shinji
Published: October 2006

6‐(10‐Hydroxy‐[1‐14C]decyl)‐2,3‐dimethoxy‐5‐methyl‐1,4‐ benzoquinone (VIII) having a specific activity of 23.4 mCi/mmol was synthesized. 9‐(2‐Hydroxy‐3,4‐dimethoxy‐6‐methyl‐[carbonyl‐14C] benzoyl)nonanol (VI) was obtained from the condensation of 3,4,5‐trimethoxytoluene with 10‐acetoxy‐[1‐14C]decanoyl chloride (V) prepared from K14CN (I). Reduction of VI with hydrogen in the presence of Pd‐Cprovided 10‐(2‐hydroxy‐3,4‐dimethoxy‐6‐methylphenyl)‐[1‐14C]decanol (VII). VII was oxidized with a Fremy's salt to give VIII in 21.5% radiochemical yield. 6‐(10‐Hydroxy‐decyl)‐2‐methoxy‐3‐[14C]methoxy‐5‐methyl‐1,4‐ benzoquinone (XI) was prepared in 34.6% radiochemical yield from the reaction of [14C]dimethyl sulfate with 6‐(10‐hydroxydecyl) ‐3‐hydroxy‐2‐methoxy‐5‐methyl‐1,4‐benzoquinone.
Synthesis of tritium labelled cholecystokinin derivative : [3H]‐Boc‐[Nle28, 31]‐ CCK27–33
Authors: Sasaki N. A. , Funakoshi S. , Potier P. , Morgat J.‐L. , Genet R. , Gacel G. , Charpentier B. , Roques B. P.
Published: October 2006

The synthesis of a new acetylenic analogue of the C‐terminal heptapeptide segment of cholecystokinin (CCK) in which the Met28 and Met31 residues are replaced by two acetylenic precursors of norleucine (Nle), L‐2‐amino‐4‐hexynoic acid (Aha), is described. Reductive tritiation of this acetylenic heptapeptide Boc‐[Aha28, 31]‐CCK27, 33 led to the labelled [3H]‐Boc‐[Nle28, 31]‐CCK27–33 which displays a specific activity of about 150 Ci/mmol. According to its full biological potency, this CCK analogue can be used for various biological assays including binding studies.
A versatile synthesis of C‐5 labeled ornithines
Authors: Wityak John , Palaniswamy Venkatapuram A. , Gould Steven J.
Published: October 2006

Using diethyl (2‐cyanoethyl)acetamidomalonate prepared from either acrylonitrile or 3‐tosylpropionitrile and diethyl acetamidomalonate, reduction with PtO2 and H2 in ethanol followed by acid hydrolysis affords ornithine in 70–95% yield. [5, 5–2H2]Ornithine and [5‐13C, 5‐15N]ornithine were prepared by these procedures.
Tritiated hexadecyl platelet activating factor (PAF)
Authors: Wyrick Steven D. , McClanahan Judy S. , Wykle Robert L. , O'Flaherty Joseph T.
Published: October 2006

We report the synthesis of the natural isomer of [3H]‐lyso platelet activating factor, [3H]‐lyso PAF (1‐0‐[9′,10′‐3H2]‐hexadecyl‐2‐lyso‐sn‐glycero‐3‐phosphocholine) and its conversion by acetylation to [3H]‐PAF(1‐0‐[9′,10′‐3H2]‐hexadecyl‐2‐acetylsn‐glycero‐3‐phosphocholine) for use in in vitro and in vivo metabolic studies. The procedure employed allows the separation of the natural (sn‐1‐0‐alkyl)lyso and unnatural (sn‐3‐0‐alkyl) isomers of the PAF precursors from a racemic mixture. The natural lyso‐Δ9, 10‐1‐0‐hexadecenyl PAF was reduced with 5.0 Ci of carrier free tritium gas to afford the tritiated lyso PAF at a specific activity of 56 Ci/mmole (115 mCi/mg).
Synthesis of 14C‐labeled indeloxazine hydrochloride (YM‐08054), a cerebral activator
Authors: Arima Hideki , Tamazawa Kazuharu
Published: October 2006

Indeloxazine hydrochloride, (±)‐2‐[(inden‐7‐yloxy)methyl]morpholine hydrochloride (YM‐08054), a new cerebral activator, was labeled with 14C for metabolic studies. The labeled material with a specific activity of 14.9 mCi/mmol was synthesized in a 42.8% radiochemical yield from potassium [14C]cyanide via a process of ten steps.
Synthesis of 13C‐labelled propylene oxide via 13C‐labelled 2‐chloropropionic acid and 2‐chloropropanol
Authors: Pri‐Bar Ilan , Buchman Ouri
Published: October 2006

1‐Methyl‐[2‐13C]ethylene oxide (I) is prepared in a four‐step synthesis, starting from [1‐13C]propionic acid. A method for an efficient α‐chlorination of low carboxylic acids is developed, 2‐chloropropionyl chloride being esterified without separation to give 72% of phenyl‐2‐chloro‐[1‐13C]propionate. The ester is hydrogenated with LiAlH4 to give 95% yield of 2‐chloro‐[1‐13C]propan‐1‐ol which is then subjected to alkaline dehydrochlorination, giving 35% yield of the isolated product (I). This micro‐scale method is also suitable for syntheses of 14C‐labelled epoxides of low molecular weight.