bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of [14C] stanozolol
Authors: Duncan D. R. , Johnston D.
Published: October 2006

The anabolic steroidal pyrazole derivative stanozolol has been labelled with 14C in the pyrazole ring. The overall chemical yield of the synthesis was 62%.
Preparation of [5‐125I]iodoacetamidoethyl aminonaphthalene‐1‐sulfonic acid in liposomes
Authors: Ogawa Naotaka , Jay Michael
Published: October 2006

The synthesis of [5‐125I]iodoacetamidoethyl aminonaphthalene‐1‐sulfonic acid ([125]IAEDANS) was accomplished beginning from sodium [125I]iodide. The product was entrapped within positively charged liposomes after ideal preparatory conditions were determined. The stability of the preparation after exposure to elevated temperatures and light was measured as well as the release rate of [125I]IAEDANS from the liposomes. Liposome‐entrapped [125I]IAEDANS is a potential radiopharmaceutical for imaging of infarcted myocardial tissue.
Radioactively labelled epoxides. Part IV. Tritium labelled α‐ and β‐methyl styrene oxides
Authors: Oesch Franz , Sparrow Alan J. , Platt Karl L.
Published: October 2006

Tritium labelled α‐methyl styrene oxide (2‐methyl‐2‐phenyloxirane) and cis‐ and trans‐β‐methyl styrene oxides (Z‐ and E‐2‐methyl‐3‐phenyl oxirane) have been prepared using tritiated water as the inexpensive source of tritium. The two geometrical isomers of β‐methyl styrene oxide were synthesized by a sequence of reactions which led to stereochemically pure products, and obviated any need to separate the isomers.
Determination of specific activity of radiohalide preparations (75Br, 77Br, 123I, 131I) by HPLC‐UV detection following chemical derivatization to 1‐halonaphthol‐2
Authors: Kloster Gerd , Laufer Peter
Published: October 2006

Specific activity is an important parameter for receptor‐binding radiopharmaceuticals. We present here a method for determination of specific activities of radiobromide (75Br, 77Br) and radioiodide (123I, 131I) using naphthol‐2 and chloramin T as reagents for derivatization. Subsequent hplc determination of the mass of 1‐halo‐naphthols‐2 on a RP 18 column is highly sensitive due to their high UV extinction coefficient in the range of 232 nm (detection limit at 220 nm: 5 × 10−13 mol) and linear over 6 orders of magnitude. It can be rapidly and conveniently performed in parallel to the actual radiopharmaceutical preparation using only a small part of the radioactive halide (less than 1 mCi for all isotopes). Dilution factors (carrier atoms per radioactive atom) found for the radiohalide using this method were 21‐100 for 75Br, 2–58 for 77Br, 3–6 for 123I and 120‐130 for 131I, respectively.
Tritium and iodine labelling of a gastrin like hexapeptide
Authors: Charon Marie‐Hélène , Van Chuong Paul Pham , Penke Botond , Morgat Jean‐Louis , Dubrasquet Marcelle , Fromageot Pierre
Published: October 2006

Tyrosine derivatives were introduced onto the N‐terminal deprotected Pentagastrin to yield precursors of labelling. The tritiated derivative Boc‐3,5‐3H2‐Tyr‐Pentagastrin of high specific radioactivity (45 Ci/mmol) was obtained by catalytic dehalogenation of the corresponding di‐iodo‐derivative in the presence of tritium gas. Iodination of Boc‐Tyr‐Pentagastrin by NaI and chloramine T led to the formation of several compounds separated by HPLC. Conditions to obtain the mono‐iodinated non‐oxidized peptide, the only biologically active derivative, were investigated. Analytical chromatographic behaviour as well as biological activity of the tritiated and of the various iodinated peptides were reported.
Synthesis of 14C labelled heptacaine and carbisocaine, new local anaesthetics
Authors: Elbert Tomáš , Marko Vladimír , Filip Jiří , Beneš Luděk
Published: October 2006

The published four step synthesis of N‐{2‐(2‐heptyloxyphenyl‐carbamoyloxy)‐ethyl}‐piperidinium chloride (5) and N‐{2‐(2‐heptyl‐oxyphenylcarbamoyloxy)‐propyl}‐diethylammonium chloride (6), which starts from o‐acetamidophenol and 1‐bromoheptane was scaled down and modified for radioisotope work. After chromatography 1064 MBq (28,7 mCi) of [heptyl‐1‐14C]heptacaine 5 and 840 MBq (22, 6 mCi) of [heptyl‐1‐14C]carbisocaine 6 were isolated. Radiochemical yields of 5 and 6 on starting 1‐bromo [1‐14C] heptane were 30% and 25%, respectively.
A simple, rapid synthesis of caffeine‐1,7‐13CH3
Authors: Pierce W. M. , Schlager J. J. , Madden R. J. , Hurst H. E.
Published: October 2006

This paper describes a simple, rapid synthesis of caffeine‐1,7‐13CH3 produced by the reaction of iodomethane‐13C with 3‐methylxanthine. The synthesis is complete in one day, requires only the most rudimentary laboratory equipment, and is amenable to large scale synthesis. Overall yield after product isolation is 82%, and the product is of 99% chemical purity and 99% isotopic purity.
Synthesis of 3‐amino‐1‐methyl‐5H‐pyrido[4,3‐b]indole‐1‐14C (TRP‐P‐2)
Authors: Reist E. J. , Bradford W. W. , Gordon G. R. , Peters J. H.
Published: October 2006

A practical 2‐step synthesis of 3‐amino‐1‐methyl‐5H‐pyrido[4,3‐b]indole‐1‐14C is described, starting from 2‐cyanomethyl indole and carbonyl‐labeled acetyl chloride.
Synthesis of [14C]‐labelled tolrestat(N‐[[5‐(trifluoromethyl)‐6‐methoxy‐1‐naphthalenyl]‐[14C]thioxomethyl]‐N‐methylglycine; AY‐27, 773)
Authors: Hicks D. R.
Published: October 2006

[14C]‐Tolrestat(N‐[[5‐(trifluoromethyl)‐6‐methoxy‐1‐naphthalenyl]‐[14C]‐thioxomethyl]‐N‐methylglycine; [14C]AY‐27, 773), a new aldose reductase inhibitor, was prepared by incorporating [14C]carbon dioxide. The intermediate, 6‐methoxy‐5‐trifluoromethyl‐[1–14C]‐naphthoic acid, prepared by carbonation of the corresponding lithiated derivative, was condensed with sarcosine methyl ester hydrochloride, converted to the thioamide and hydrolyzed. [14C]Tolrestat, having a specific activity of 52.7 μCi/mg was obtained in 26% overall yield from [14C]barium carbonate and had a radiochemical purity of 97%.
Synthesis of site specifically deuterated primaquines II. N‐alkyl deuterated primaquines
Authors: McChesney James D. , Sarangan Srinivasan
Published: October 2006

Two site specifically deuterated primaquines were prepared. 4′,4′‐Dideutero primaquine 3 was obtained from the corresponding dideutero alcohol which was prepared by the low temperature reduction of the ester compound 4 with lithium aluminium deuteride. 1′‐Deutero primaquine r was prepared by the reductive alkylation of 6‐methoxy‐8‐aminoquinoline with N‐(2‐oxopentyl)‐phthalimide in the presence of sodium cyanoborodeuteride followed by removal of protective phthalimide group.
Synthesis of 13C labeled n‐alkylchlorosi lanes
Authors: Gilpin R. K. , Gangoda M. E.
Published: October 2006

This report describes the synthesis of various carbon‐13 enriched n‐alkylchlorosilanes with label in corporation at selective positions along the alkyl chains. Compounds which were prepared were:

n‐nonyltrichlorosilane‐1‐13C

n‐dodecyltrichlorosilane‐4‐13C

n‐dodecyldimethylchlorosilane‐4‐13C

n‐tridecyltrichlorosilane‐12‐13

n‐dodecyltrichlorosilane‐12‐13C

n‐tridecyldimethylchlorosilane‐12‐13C
Synthesis of sodium [1,4‐14C] aurothiomalate
Authors: Taylor Andrew , King Laurence J. , Marks Vincent
Published: October 2006

[1,4‐14C] Acetylthiomalic anhydride was prepared from [1,4‐14C]maleic anhydride and thioacetic acid. Removal of the acetyl group was achieved by sodium hydroxide hydrolysis and the resultant [1,4‐14C]thiomalic acid was extracted into ethyl acetate. Sodium [1,4‐14C]aurothiomalate was prepared by the reaction of gold(I) iodide with [1,4‐14C] thiomalic acid and precipitation of the sodium salt from alkaline solution by the addition of ethanol. The products were demonstrated to have a radiochemical purity of > 98% by radio‐scanning of thin‐layer chromatograms and scintillation counting of segments of the chromatogram.
Synthesis of 14C‐labeled pramiracetam hydrochloride, N‐[2‐(bis[1‐methylethyl]amino)ethyl]‐2‐oxo‐1‐pyrrolidine‐acetamide‐α‐14C hydrochloride, CI‐879 hydrochloride
Authors: Hartman Jon D. , Huang C. C. , Butler D. E.
Published: October 2006

Pramiracetam hydrochloride, N‐[2‐[bis(1‐methylethyl)amino] ethyl]‐2‐oxo‐1‐pyrrolidineacetamide hydrochloride, CI‐879, a new potential clinically useful cognition activator, was labeled with 14C. Bromoacetic‐2‐14C acid was converted to its ethyl ester which reacted with sodium 2‐pyrrolidinone to yield ethyl 2‐oxo‐1‐pyrrolidineacetate‐α‐14C acid. Treatment of the latter with N,N‐bis(1‐methylethyl)‐1,2‐ethanediamine gave pramiracetam free base which was subsequently converted to the hydrochloride salt.
Synthesis of 2H, 13C and 15N‐isotopomers of acetonitrile and thioacetamide
Authors: Anthoni Uffer , Nielsen Per Halfdan
Published: October 2006

The syntheses of all the possible 2H, 13C, and 15N singly and multiply labelled isotopomers of acetonitrile and thioacetamide are described. The pathway includes reaction between methyl iodide and potassium cyanide followed by treatment of the acetonitrile with diphenylphosphinodithioic acid to give thioacetamide, purified by sublimation in an overall yield of 55–60%.
Synthesis of (2RS)‐[3‐13C]‐ and (2RS)‐[3‐14C] leucine
Authors: Anastasis Panayiotis , Overton Karl , Singh Sheo Bux
Published: October 2006

(2RS)‐[3‐13C]‐ and (2RS)‐[3‐14C] Leucine have been prepared via carbonation of the Grignard reagent 2 from 2‐bromopropane, with 13CO2 or 14CO2. Reduction of the labelled isobutyric acid, displacement of the derived isobutyl brosylate 5 with acetamidomalonic ester and hydrolysis afforded (2RS)–[3‐*C] leucine with 55–65% incorporation of label from Ba*CO3 on a scale of 5–25 mmol.
Synthesis of [14C1]squaric acid
Authors: Heys J. R. , Chew E. H.
Published: October 2006

The title work proceeds in five steps and 16% overall yield from sodium [1‐14C]acetate, which was converted by bromination followed by ethoxide displacement and reaction with phthaloyl dichloride to ethoxy[1‐14C]acetyl chloride. The thermal[2+2]cycloaddition of tetraethoxyethene with ethoxy[1‐14C]ketene, derived from base induced elimination from ethoxy[1‐14]acetyl chloride following the method of Bellus, provided an 80% yield of 1‐(ethoxy[1‐14C]acetoxy)‐2,3,3,4,4‐pentaethoxy‐l‐[1‐14C]‐cyclobutene. Acid hydrolysis and liquid‐liquid extraction afforded [14C]squaric acid.
Preparation of labelled phospholipids: Acylation of 2‐lysophosphatidylcholine with [9,10‐3H]oleic acid
Authors: Orlando P. , Giordano C. , Binaglia L. , De Sanctis G.
Published: October 2006

1‐Acyl‐2‐[9,10‐3]oleoyl‐sn‐glycero‐3‐phosphorylcholine was prepared by acylating 1‐acyl‐sn‐glycero‐3‐phosphorylcholine with labelled oleic acid, in the presence of dicyclohexylcarbodiimide (DCC), as condensing agent. A simple column chromatographic procedure allowed both purification of the labelled phospholipid and recovery of the unreacted oleic acid, at the end of the reaction. In standard conditions, yields of 35–40 % were obtained.

The major feature of this procedure is that it is a “one pot” reaction not requiring the isolation of an activated acid derivative prior to esterification.

This method is also suitable for preparing labelled phospholipids other than phosphatidylcholine, provided that free or unmasked amino or hydroxyl groups are absent in the molecule.
Synthesis of tritium‐labeled DL‐γ‐carboxyglutamic acid and its cyclic form 5‐oxo‐2,4‐pyrrolidine dicarboxylic acid
Authors: Ishikawa Yoshinori , Wuthier Roy E.
Published: October 2006

By condensing diethyl ethoxymethylenemalonate with diethyl acetamidomalonate, 5‐hydroxy‐2,4‐dicarbethoxypyrrole was prepared. Hydrogenation over Pt‐C to 5‐oxo‐2,4‐dicarbethoxypyrrolidine, followed by alkaline hydrolysis gave γ‐carboxyglutamate. Mild alkaline hydrolysis yielded 5‐oxo‐2,4‐pyrrolidine dicarboxylic acid which was isolated as the cyclohexylamine salt. These procedures were applied to prepare tritium‐labeled γ‐carboxyglutamic acid (4.9 Ci/mmol) and its cyclic form (6.1 ci/mmol).
Synthesis of [1,2,3,4,5‐13C5] palmitic acid
Authors: Yuan Sun‐Shine , Ajami Alfred M.
Published: October 2006

Carbonylation of 1‐undecene with 13CO under a hydrogen atmosphere with palladium‐stannous chloride catalyst afforded [1‐13C]dodecanoic (lauric) acid on a 0.25 mole scale. Reduction to the alcohol and treatment with concentrated HBr gave 1‐[1‐13C]bromododecane which was used to alkylate the Na+, Li+ mixed diananion of ethyl acetoacetate selectively at the 4‐position in 73% yield. Reductive deoxygenation of the resulting 3‐oxo intermediate, followed by saponification and purification, gave [1,2,3,4,5‐14C5]hexadecanoic (palmitic) acid in 50% yield.
Synthesis of high specific activity 1,8‐naphthalic anhydride
Authors: Tanaka Fred S. , Wien Ronald G. , Hoffer Barry L.
Published: October 2006

The synthesis of [14C‐carboxyl] 1,8‐naphthalic anhy‐anhydride of high specific activity (31.8 mCi/mmol) is reported. The 14C was introduced by carbonation of the Grignard reagent, 8‐bromo‐1‐naphthylmagnesium iodide, that was prepared from 8‐bromo‐1‐iodonaphthalene. The overall radiochemical yield for the reaction scheme was 63.7% based on barium carbonate‐14C.
Marquage par 14C du methoxy‐7 nitro‐2 naphto [2,1‐b] furanne (R 7000)
Authors: Madelmont J. C. , Parry D. , Maurizis J. C. , Buisson J. P. , Royer R. , Meyniel G.
Published: October 2006

7‐methoxy −2‐nitro naphto [2,1‐b] furan was 14 labelled by C on two positions:

on the position one of the furan ring starting with sodium formiate

on the methoxy group by means of methyl iodide.
Radiolysis of aqueous and aqueous‐ethanolic solutions of histamine
Authors: Kopoldová J. , Vlasáková V.
Published: October 2006

Aqueous solutions of histamine and imidazole were gamma‐irradiated in the absence and presence of ethanol. The protective effect of ethanol on the radiation cleavage of the imidazole ring depends on the pH of irradiated solutions: at neutral pH the presence of ethanol decreases radiation degradation of imidazole skeleton whereas at acidic pH it does not play any protective role. On the contrary in irradiated aqueous‐ethanolic solutions of histamine 2 HCl (pH 4.5) some additional reactions between histamine and products of radiolysis of ethanol, mainly with acetaldehyde, take place leading to the increase of total radiation loss of histamine and to the formation of further radiation products. Similar products were also found in 3H preparations of histamine stored in aqueous‐ethanolic solutions. Possible mechanisms of radiation degradation of histamine were discussed.
Remote system for production of carbon‐11 labeled glucose via photosynthesis
Authors: Dence Carmen S. , Lechner Keith A. , Welch Michael J. , Kilbourn Michael R.
Published: October 2006

A remote system has been constructed for the preparation of 11C‐glucose via photosynthesis. The system is totally contained in a shielded hood, with all manipulations done from the outside. This system is capable of routine delivery of 25–50 mCi of 11C‐glucose which has a radiochemical purity >95% and is sterile and pyrogen free. The design, construction and operation of this system are fully described.
Syntheses of 5′‐deoxy‐5‐[18F] fluorouridine and related compounds as probes for measuring tissue proliferation in vivo
Authors: Shiue Chyng‐Yann , Wolf Alfred P. , Friedkin Morris
Published: October 2006

A rapid synthesis of 5′‐deoxy‐5‐[18F] fluorouridine (3a) from either [18F] F2 or CH3 CO2 18F is described. Fluorination of 2′,3′‐di‐O‐acetyl‐5′‐deoxyuridine (1a) with either [18F] F2 or CH3 CO2 18F in glacial acetic acid at room temperature followed by hydrolysis with sodium methoxide in methanol gives 5′‐deoxy‐5‐[18F] fluorouridine (3a) in radiochemical yields of 20‐25% in a synthesis time of 80 min from EOB. The same method also has been used to synthesize 5‐[18F] fluorouridine (3b) and 2′‐deoxy‐5‐[18F] fluorouridine (3c) in similar radiochemical yields. Acetyl hypofluorite (CH3 CO2F) is proposed as an intermediate for these reactions.
Synthesis of carbon‐14 labeled 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone
Authors: Castonguay Andre , Hecht Stephen S.
Published: October 2006

The potent carcinogen 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanone (NNK) is present in tobacco and tobacco smoke. [Carbonyl14C]NNK (6) was synthesized in 27% overall yield. [Carboxyl‐14C] nicotinic acid (1) was esterified with benzyl alcohol and the ester 2 was alkylated by 3‐lithio‐N‐methylpyrrolidin‐2‐one (3). The resulting keto‐lactam 4 was hydrolyzed and decarboxylated by treatment with boiling hydrochloric acid. Nitrosation at pH 4.0 gave [carbonyl‐14C]NNK (6). Carbonyl reduction of [carbonyl‐14C]NNK with either sodium borohydride or cultured rat liver slices gave [carbinol‐14C] 4‐(methylnitrosamino)‐1‐(3‐pyridyl) butan‐1‐ol‐(7).
Synthesis of L‐glutamic acid stereospecifically labeled at C‐4 with deuterium
Authors: Ducrocq Claire , Maréchal Paulette Decottignies‐Le , Azerad Robert
Published: October 2006

4‐[2H2]‐L‐glutamic acid was prepared in excellent yield by enzymatic reductive amination of 4‐[2H2]‐2‐ketoglutaric acid. The synthesis of stereospecifically deuterated (4 R) and (4 S)‐[4‐2H2]‐L‐glutamic acids from (2 RS, 4 S) and (2 RS, 4 R)‐4‐hydroxyglutamic acids, involving a reduction step by sodium cyanoborodeuteride, was shown to proceed with 75% inversion of configuration.
Synthesis of 14C‐labelled propanesulphonates ‐ application to surfactants and hydrophilic polymers
Authors: Hodgson Philip K. G. , Tinley Edward J.
Published: October 2006

1,3‐[2‐14C]Propanesultone was identified as a versatile reagent for the preparation of a wide range of 14C‐labelled surfactant and hydrophilic polymer propanesulphonates in a convenient, efficient, one‐step reaction. A surfactant, sodium dinonylphenylhexaethoxy [2‐14C] propanesulphonate was prepared by the reaction of the corresponding ethoxyalcohol with 1,3‐[2‐14C]propanesultone in xylene at 140° for 2.5h using sodium hydride as base. Conversion, as measured by High Performance Liquid Chromatography, was 77%. Pure sulphonate was obtained after silica gel column chromatography at specific activity 31.5 μCi/g in 52% yield. Structure was confirmed by 1H and 13C NMR spectroscopy. A low molecular weight hydrophilic polymer sulphonate has been prepared in radiolabelled form by the reaction of poly(vinylalcohol) MW 14,000 with 1,3‐[2‐14C]‐propanesultone in dimethylsulphoxide with potassium carbonate as base at 85° for 18h. The 14C‐labelled poly(vinylalcohol) potassium propane‐sulphonate so formed had specific activity 8.0 μCi/g and was obtained in 96% yield. The degree of propanesulphonation of polymer was 19.5%.
Preparation de l'acide méso diamino‐2, 6 heptane‐dioique‐1, 7‐[3H‐3, 4, 5] (méso‐diamino pimelique‐[3H‐3, 4, 5])
Authors: Schott D. , Rousseau B. , Beaucourt J. P. , Lellouche J. P. , Pichat L.
Published: October 2006

Meso 2, 6‐diamino [3H‐3, 4, 5] 1, 7‐heptanedioc acid‐ (meso [3H‐3, 4, 5] DAP) specific activity 30 Ci/mM was obtained by catalytic dehydrohalogenation of meso 3‐chloro and 4‐chloro DAP. LL, DD and meso DAP were analytically separated by cellulose thin layer chromatography (methanol‐water‐7 : 3).
A general method for the preparation of 14C‐labeled metabolically stable prostaglandins
Authors: Muccino Richard R. , Liebman Arnold A. , Cupano Joseph , Malarek David H.
Published: October 2006

A method is described for the preparation of 5‐bromopentanoic‐5‐14C acid which is inserted via the Wittig ylid into the desired prostaglandin intermediate in the last carbon‐carbon bond forming step of the Corey synthesis. Three different prostaglandins were prepared carbon‐labeled (both 14C and 13C) in the metabolically stable position 5 to illustrate the general utility of this procedure.
Synthese von ruthenocenoyl ‐ 1‐1, 1′‐diglycin ‐ ethylester durch Austausch von Ferrocenoyl‐glycinester mit 103RuCl3
Authors: Schachschneider Gert , Wenzel Martin
Published: October 2006

Ruthenocenoyl‐glycine derivatives labelled with radioactive ruthenium (97Ru, 103Ru), showing a clearance similar to Hippuran, are potential radiopharmaceuticals. Synthesis, reaction mechanism and identification of ruthenocenoyl‐1, 1′‐diglycine derivatives are described.
Synthesis of 14C‐labeled halogen substituted indole‐3‐acetic acids
Authors: Baldi Bruce G. , Slovin Janet Pernise , Cohen Jerry D.
Published: October 2006

A general method for microscale synthesis of 14C‐labeled indole‐3‐acetic acids with halogen substitutions in the benzene ring is described. The method utilizes halogen substituted phenylhydrazines reacted with [14C]‐2‐oxoglutarate to generate the halogenated indole‐3‐acetic acid. 3‐Chlorophenyl‐hydrazine yielded a mixture of the 4 and 6 chloro compounds that was resolved by C18‐reverse phase high performance liquid chromatography.
Synthesis of 14C‐ and 3H‐labelled 4‐(4‐nitrophenyl)aminophenylisothiocyanate (GO 9333 / CGP 4540; amoscanate
Authors: Anjaneyulu B. , Maller R. K. , Nagarajan K. , Kueng W. , Wirz B.
Published: October 2006

Amoscanate labelled with carbon‐14 on the isothiocyanate carbon atom was prepared in an overall yield of 13% at a specific activity of 4.13 μCi/mg from potassium [14C]thiocyanate. The 4‐nitro[U‐14C]phenyl ring labelled compound was synthesized in 20.4% overall yield from [U‐14C]aniline at a specific activity of 12.2 μCi/mg. The corresponding tritiated compound was prepared from 4‐amino[2‐3H]acetanilide at 112 μCi/mg. Labelling with tritium in the aromatic ring bearing the isothiocyanate group was achieved by catalysed halogen‐tritium replacement. However, for pharmacokinetic and metabolism studies in experimental animals, the 14C‐ and 3H‐labels associated with the phenylisothiocyanate moiety subsequently proved disadvantageous because of the instability of the labels in vivo.
Bile acids. LXXI. A new synthesis of (25R)‐3α, 7α‐dihydroxy‐[5α,6α‐3H2]‐5α‐cholestan‐26‐oic acid (1)
Authors: Tal Daniel M. , Elliott William H. , Doisy Edward A.
Published: October 2006

Tritiation of 7‐oxo‐5‐cholestene‐3β,26‐diol diacetate afforded a mixture of [5α,6α‐3H2] products which were reduced with lithium aluminum hydride to provide a mixture of [5α,6α‐3H2]‐3β, (7α and 7β), 26‐triols an 3β, 26‐diol. Oxidation with Jones reagent provided 3,7‐dioxo and 3‐oxo‐[5α,6α‐3H2]‐5α‐cholestanoic acids which were separated. Stereospecific reduction of the 3,7‐dioxo methyl ester with K‐Selectride followed by alkaline hydrolysis afforded (25R)‐3α,7α‐dihydroxy‐[5α,6α‐3H2]‐5α‐cholestan‐26 ‐oic acid.
Radiolabeling of the B‐ and C‐ring of estradiol using no‐carrier‐added bromine‐77
Authors: Hylarides Mark D. , Leon Alberto A. , Mettler Fred A. , Wilbur D. Scott
Published: October 2006

Two estradiol derivatives, Δ6‐ and Δ9‐estradiol 3‐acetate (1) and (2) were prepared and allowed to react with Na77Br and N‐chlorosuccinimide (NCS) in methanol. The rapid addition of 77Br‐OCH3 to the B‐ring (Δ6,7) and C‐ring (Δ9,11) double bonds produced brominated adducts 3a and 4b, respectively, in excellent radiochemical yields. Product 3a showed excellent radiochemical stability over a 3‐day period; however, attempts to prepare the free phenol 5 by removal of the 3‐acetyl group with base, result in loss of all activity from the molecule. Contrary to this, the 3‐acetyl group of 4b was readily removed with base without loss of radioactivity and the resultant phenol 6 could be isolated in 73% radiochemical yield. Unfortunately 6 was moderately unstable since 80% of the activity was dissociated from the compound within 48 hours.
Synthesis of radioiodinated analogs of 2‐phenylpyrazolo[4,3‐c]‐quinolin‐3 (5H)‐one by a modified triazene method
Authors: Maeda Minoru , Komori Hiroshi , Dohmoto Hideki , Kojima Masaharu
Published: October 2006

No‐carrier‐added 2‐(4‐[131I]iodophenyl)‐ and 8‐[131I]iodo‐2‐phenylpyrazolo[4,3‐c]quinolin‐3(5H)‐one were prepared in isolated radiochemical yields of 11.6 and 5.4%, respectively, by acid decomposition of aryl triazenes in acetonitrile. A modified triazene method involving solid‐phase decomposition reactions increased the isolated radiochemical yields to 15–35%.
Synthesis of 14C‐ and 3H‐labeled CI‐911 (dihydro‐1H‐pyrrolizine‐3, 5 (2H, 6H)‐dione)
Authors: Hartman J. D. , Dodd J. H. , Hicks J. L. , Hershenson F. M. , Huang C. C. , Butler D. E.
Published: October 2006

CI‐911 [dihydro‐1H‐pyrrolizine‐3,5(2H, 6H)‐dione] (1), a new cognition activating agent, was radiolabeled with 14C and 3H. The 14C‐labeled synthesis was accomplished using nitromethane‐14C as the starting material to result in an overall radiochemical yield of 9.2%. The 3H‐labeled CI‐911 was synthesized with a specific activity of 28.1 Ci/mmol by catalytic tritium reduction of 3‐(5‐oxo‐2‐pyrrolidinyl)‐2‐propenoic acid, phenylmethyl ester, followed by cyclization upon heating with acetic anhydride.
Synthesis of racemic [2‐11C]phenylglycine
Authors: Halldin Christer , Långström Bengt
Published: October 2006

The synthesis of racemic [2‐11C]phenylglycine, starting with 11CO2′ is reported. The [11C]benzaldehyde, prepared as previsously described in a two‐step reaction from the corresponding [11C]benzoic acid salt, was used in a modified Bücherer‐Strecker reaction. The radiochemical yield of [2‐11C]phenylglycine in benzaldehyde‐added experiments was 20 %, and in non‐added experiments 6 % (corrected for decay). The overall synthesis time, starting with 11CO2, was 50 min (including LC separation). The radiochemical purity was higher than 99 %.
Regioselective synthesis of (E)‐2‐[2H or 3H]‐5‐succinimido‐4‐oxo‐pent‐2‐enoic acid
Authors: Gutman Arie L. , Campbell John B.
Published: October 2006

The synthesis of highly enriched C‐2 deuteriated and tritiated (E)‐5‐succinimido‐4‐oxo‐pent‐2‐enoic acid for use in enzymatic reduction is described. The starting materials 3‐methoxycarbonyl‐[3‐2H]propionyl chloride and 3‐methoxycarbonyl‐[3‐3H]propionyl chloride were prepared in high yield by regioselective deuteriation or tritiation of monomethyl succinate. The synthetic route involved regioselective bromination of 5‐succinimidolaevulinic acid followed by dehydrobromination.
Synthesis and purification of [4′‐3H]‐mebendazole
Authors: Dawson M. , Williams P. , Long M. , Watson T. R.
Published: October 2006

A method for the synthesis and purification of mebendazole specifically labelled with tritium in the 4′ position is described.
Synthesis of 1‐[14C]‐phenyl‐1‐(3,4‐dimethyl)phenylethane, a component of some PCB replacement materials
Authors: Willis D. E. , Addison R. F.
Published: October 2006

1‐[14C]‐phenyl‐1‐(3,4‐dimethyl)phenylethane, a labeled analogue of a PCB replacement used as an ink solvent in pressure sensitive copying paper and as a capacitor dielectric, has been prepared. The Grignard reagent derived from 14C‐bromobenzene was condensed with methyl(3,4‐dimethyl)phenylketone and the resulting tertiary alcohol was hydrogenolyzed. The final yield was 53.1% based on 14C‐bromobenzene; final specific activity of the product was 1.29 mCi·mmole−1, which is adequate for metabolic studies.
A convenient synthesis of [1‐14C]acetylcholine iodide
Authors: Anjaneyulu B.
Published: October 2006

A convenient synthesis of [1‐14C]acetylcholine iodide in two steps is described. β‐Dimethylaminoethanol is acetylated with [1‐14C]acetic anhydride and the ester β‐dimethylaminoethyl [1‐14C]acetate quaternised with methyl iodide to afford [1‐14C]acetylcholine iodide in an overall material yield of 50–52% and radiochemical yield 18%.
Factors influencing reactivity of thermal H(T) atoms with solids. I. Physical effects
Authors: Ehrenkaufer Richard E. , Hembree Wylie C. , Wolf Alfred P.
Published: October 2006

The effects of surface area and the nature of the surface were investigated for samples labeled by the microwave dischare activation (MDA) ‐ tritium atom technique. When labeling powdered samples of different chemical structure the crude specific activity (prior to purification) was shown to increase linearly with the specific area (m2/g) although the final specific activity of the purified compound was found to be dependent on the chemical nature of reacting sample. Samples deposited on high surface area, microporous membrane filters, showed large increases in specific activity was found to be a function of sample thickness (mg/m2) reaching a maximum when the amount of sample was less than or equal to a monolayer on the filter surface and decreased as the reciprocal of the sample weight when a monolayer was exceeded.

Finally, a survey of the labeling properties of 20 selected filters using L‐proline as a model compound was carried out. Cellulosic (hydrophilic) filters were found in general to yield labeled proline of the highest specific activities whereas the hydrophobic (vinyl, fluorocarbon, etc.) yielded the lowest. It was also found that the specific activity of most (15 of 20) of the filters was linearly related to tritium “yield” (% tritium recovered in proline after purification) in the labeled proline.
Syntheses of 14C‐labelled prizidilol dihydrochloride
Authors: Saunders D , Warrington B H
Published: October 2006

Two syntheses of radiolabelled prizidilol dihydrochloride (DL)3‐[2‐(3‐t‐butylamino ‐2‐hydroxypropoxy)phenyl]‐6‐hydrazino‐pyridazine dihydrochloride) are described.

1. A ten stage synthesis (Scheme 1) which gave [3,6‐14C2] prizidilol dihydrochloride (10) in an overall yield of 0.91%.

2. A later, alternative procedure (scheme 2) leading to [4,5‐14C2] prizidilol dihydrochloride (16) with an overall radiochemical yield of 8%.
Synthesis of 5‐ethyl‐1,3,8‐trimethyl‐1H‐[5‐14C] imidazo[1,2‐c]pyrazolo[3,4‐e]pyrimidine
Authors: Hicks J. L. , Huang C. C.
Published: October 2006

5‐Ethyl‐1,3,8‐trimethyl‐1H‐imidazo[1,2‐c]pyrazolo[3,4‐e]pyrimidine, a new antipsychotic agent, was labeled with 14C. The labeled compound was synthesized from barium [14C]carbonate in four steps. [1‐14C]propanoic acid, made from 14CO2 and ethylmagnesium bromide, was treated with 5‐(4,5‐dihydro‐4‐methyl‐1H‐imidazol‐2‐yl)‐1,3‐dimethyl‐4‐nitro‐1H‐pyrazole in the presence of dicyclohexylcarbodiimide to give 2‐(1,3‐dimethyl‐4‐nitro‐1H‐pyrazol‐5‐yl)‐4, 5‐dihydro‐4‐methyl‐1‐(1‐[1‐14C]oxopropyl)‐1H‐imidazole. This was reduced and cyclized to 5‐ethyl‐7, 8‐dihydro‐1,3,8‐trimethyl‐1H‐[5‐14C]imidazo[1,2‐c]pyrazolo[3,4‐e]pyrimidine. Oxidation gave the title compound in an overal radiochemical yield of 35% with a specific activity of 4.88 mCi/mmol.
Multimillicurie preparation of 2‐[18F]‐fluoro‐2‐deoxy‐D‐glucose via nucleophilic displacement with fluorine‐18 labelled fluoride. 1. Purification and quality control procedures
Authors: Vora M. M. , Boothe T. E. , Finn R. D. , Kothari P. J. , Emran A. M. , Carroll S. T. , Gilson A. J.
Published: October 2006

High performance liquid chromatography (HPLC) has been utilized for the preparation of 2‐[18F]‐fluoro‐2‐deoxy‐D‐glucose (18F‐2FDG) in 98.3 ± 1.5% radiochemical purity. Employing an enriched water target for fluoride‐18 labelled fluoride ion production, the time required for synthesis and purification of the finished product averaged 150 minutes from end of bombardment (EOB). The average radiochemical yield of the pharmaceutical product at EOB was 18%.
Nitroacridines with selective toxicity towards hypoxic mammalian cells: Synthesis and stability of tritiated derivatives
Authors: Denny William A. , Chambers David , Stewart Georgina M. , Wilson William R.
Published: October 2006

The clinically‐used antitumour drug nitracrine (9‐[3‐dimethylaminopropyl] amino‐1‐nitroacridine) shows increased toxicity towards mammalian tumour cells under hypoxic conditions, but several closely‐related nitroacridines do not show this selectivity. To aid studies of the mode of action of this class of compound four different tritium‐labelled nitroacridines [G‐3H] 9‐amino‐1‐nitroacridine, [G‐3H]9‐methylamino‐1‐nitroacridine, 9‐(3‐(dimethylamino)propylamino) [G‐3H]‐1‐nitroacridine, and 9‐(3‐(dimethylamino) propylamino) [G‐3H]‐3‐nitroacridine were prepared from tritiated sodium N‐(3′‐nitrophenyl) anthranilate. Optimum conditions for addition of the amine sidechain to the intermediate chloronitronacridines varied markedly for each derivative. The tritiated compounds proved stable as solid salts, but dilute solutions rapidly hydrolvsed to the nitroacridones, in a reaction which was assisted by light.
Preparation of ring‐tritiated and of aldehyde‐14C‐labelled 1‐pyrenecarboxaldehyde
Authors: Posner Gary H. , Barness Itzhak , Biggley William H. , Seliger Howard H. , Kaplan David C.
Published: October 2006

A short, direct, and efficient synthesis of very high specific‐activity ring‐tritiated 1‐pyrenecarboxaldehyde is described. A novel aspect of this synthesis involves direct bromination of an aromatic pyrene system carrying an electronwithdrawing aldehyde group. Synthesis of 14C‐labelled 1‐pyrene‐carboxaldehyde is also described. Each of these compounds was converted in one step into the correspondingly radiolabelled trans‐1‐(2′‐methoxyvinyl) pyrene.
Synthesis of hexadeuterated hexestrol (R, S)‐3,4‐di‐(4‐hydroxyphenyl)hexane‐1,1,1,6,6,6‐2H6
Authors: de Clercq P. J. , Hoflack J. M. , van Royen L. A. , van Peteghem C. H.
Published: October 2006

A short and stereoselective synthesis of hexadeuterated hexestrol is described, involving catalytic hydrogenation of Z‐3,4‐di‐(4‐methoxyphenyl)hex‐3‐ene‐1,1,1,6,6,6‐2H6 followed by demethylation using sodium thioethoxide in dimethyl formamide.
Synthesis of N‐p‐azidophenylethyl‐7,8‐dihydronormorphine and its 7,8‐ditritio analogue. Potential opiate receptor photoaffinity labels
Authors: Cooper Geoffrey K. , Rapoport Henry
Published: October 2006

The morphine derivatives N‐p‐azidophenylethyl‐7,8‐dihydronormorphine (l) and its 7,8‐ditritio analogue (la) were synthesized from morphine. This material, a potential photoaffinity label with high specific radioactivity and with opiate agonist activity comparable to morphine, may be useful for labeling of opiate receptors.
Preparative isolation of [U‐14C]solanesol from 14CO2‐chamber grown tobacco
Authors: Hassam Saifunnissa B.
Published: October 2006

A method for the preparative isolation of [U‐14C]solanesol from 14CO2‐chamber grown tobacco is described. Freeze‐dried tobacco leaves were Soxhlet extracted with methylene chloride. Fractionation of the extract by silica gel chromatography yielded crude solanesol. Subsequent purification by normal phase high pressure liquid chromatography yielded [U‐14C]solanesol with a total activity of 474 m̈Ci, a specific activity of 0.5 mCi/mmol, and a radiochemical purity of 95% as determined by RP‐HPLC. The chemical purity was 97% and the chemical identity of the isolated compound was confirmed by co‐chromatography with reference material and by mass spectroscopy.
The preparation of 14C, 35S and 13C labelled forms of omeprazole
Authors: Crowe A M , Ife R J , Mitchell M B , Saunders D
Published: October 2006

The syntheses of [benzimidazole‐2‐14C]omeprazole, [benzimidazole‐2‐13C]omeprazole, [35S]omeprazole and [2‐pyridyl‐14C‐methyl]‐omeprazole are described. The first three compounds were prepared from the approprlate isotopically labelled carbon disulphide. The key step in the synthesis of [2‐pyridyl‐14C‐methyl]omeprazole is nucleophilic alkylation of a 1‐ethoxypyridinium salt using [14C]methyl magnesium idodide. This is the first time that a reaction of this type has been used to prepare a 2‐[methyl]‐14C]methylpyridine.
I‐125 and I‐123 labelled iodobenzyl bromide, a useful alkylating agent for radiolabelling biologically important molecules
Authors: Wilson Alan A. , Dannals Robert F. , Ravert Hayden T. , Burns H. Donald , Wagner Henry N.
Published: October 2006

The radioiodination of 4‐trimethylsilylbenzyl bromide in acetic acid with no carrier added I‐125 and I‐123 iodide ion and N‐chlorosuccinimide (NCS) is a rapid, high yielding process which produces high specific activity 4‐[I‐125 or I‐123]iodobenzyl bromide. This radiolabelled alkylating agent has been efficiently reacted with N,N‐dimethylaniline and triphenylphosphine to generate radiolabelled quaternary ammonium and phosphonium salts, and should be useful for labelling other biologically important molecules which possess suitable nucleophilic functional groups.
Synthesis of tritium labelled adinazolam with high specific activity
Authors: Palmer John R.
Published: October 2006

Tritium labelled 8‐chloro‐1‐[(dimethylamino)methyl]‐6‐phenyl‐4H‐s‐triazolo[4,3‐a][1,4]benzodiazepine was prepared from [3H]bromomethane and 8chloro‐1‐[(N‐methylamino)methyl]‐6‐phenyl‐4H‐s‐triazolo[4,3‐a][1,4]benzodiazepine. The latter compound was efficiently obtained from 8‐chloro‐6‐phenyl‐4H‐s‐triazolo[4,3‐a)[1,4]benzodiazepine by hydroxymethylation, mesylation and mesylate displacement with aqueous methylamine. The titled product had a specific activity of 80 Ci/mmole.
Synthesis of D3‐metoclopramide
Authors: Jamet G. , Kerr Robert R. , Staveris S. , Jung L. , Koffel J. C.
Published: October 2006

Metoclopramide‐d3 with the three deuterium atoms in the methoxy function ortho to the benzamide group was synthesized. A previously published synthesis was followed but was extensively modified in the final steps to increase overall yield. Structure was verified by NMR and GC‐MS.
Synthesis and evaluation of fluorinated derivatives of fentanyl as candidates for opiate receptor studies using positron emission tomograpry
Authors: Hwang Dah‐Ren , Feliu Anthony L. , Wolf Alfred P. , Macgregor Robert R. , Fowler Joanna S. , Amett Carroll D. , Holland H. Jean , Carr Kenneth , Simon Eric J.
Published: October 2006

Three fluorinated derivatives of fentanyl, fluorofentanyl (3), keto‐fluorofentanyl (5), and fluorofentanol (6), were synthesized and their abilities to compete with 3H‐diprenorphine for binding sites in guinea pig brain membranes were determined. The relative potencies were fentanyl > 3 ∼ 6 ≫ 5. On the basis of its apparent affinity for opiate receptors and its relative ease of synthesis,.6 was selected for further study. Fentanyl was slightly better than.6. in its ability to compete with [3H]naltrexone for binding sites in rat brain membranes. Both fentanyl and 6 exhibited a similar high “sodium ratio” (quotient of the IC50's against [3H]naltrexone in the presence and absence of sodium chloride) generally characteristic of opiate agonists. The analgesic potencies of fentanyl and 6 were determined in rats by measuring suppression of locomotion and vocalization responses to footshock. 6 appeared slightly less potent than fentanyl, but produced a similar analgesia and catalepsy which was entirely blocked by pretreatment of rats with naloxone, an opiate antagonist. A rapid synthesis of [18F]‐6 was developed and the tissue distribution of [18F]‐6 in mice was determined 5, 60, and 120 minutes after intravenous injection. The use of this general route to 18F‐labeled derivatives of fentanyl for studies of the opiate receptor using positron emission tomography is planned.
Synthesis of tritium labelled 7‐dehydrocholesterol 5β,6β‐oxide
Authors: Michaud Dennis P. , Nashed Nashaat T. , Jerina Donald M.
Published: October 2006

We report the synthesis of tritiated 7‐dehydrocholesterol 5β,6β‐oxide in high specific activity. Oxidation of 7α‐bromo‐cholesterol 5β,6β‐oxide to the 3‐keto epoxide followed by borotritide reduction, in a special buffer‐organic solvent system to minimize undesired rearrangement, regenerated the 3β‐hydroxyl group. Base‐assisted elimination produced the title compound.
Synthesis of [14C]zolpidem
Authors: Allen John , Tizot André
Published: October 2006

The synthesis of [14C]Zolpidem, a new hypnotic agent having a non‐benzodiazepine structure, is described. This compound was synthesised in a 64% overall radio‐chemical yield from potassium[14C]cyanide and with a specific radioactivity of 56 mCi/mmol. It was used for pharmacokinetic and drug metabolism studies.
Syntheses of carbon‐14 and sulfur‐35 labeled 2‐(morpholinothio)benzothiazoles and carbon‐14 labeled 2‐(cyclohexylaminothio)benzothiazoles
Authors: Tanaka A , Fukuoka M , Adachi T , Yamaha T
Published: October 2006

Some vulcanizing accelerators, mercaptobenzothiazole derivatives labeled with carbon‐14 or sulfur‐35 were prepared. 2‐(Morpholinothio)benzothiazole labeled with carbon‐14 or sulfur‐35 of the sulfhydryl group at position 2 was synthesized by oxidative condensation with sodium hypochlorite from a mixture of morpholine and 2‐mercaptobenzothiazole‐2‐14C or 2‐mercaptobenzothiazole‐2‐35S. The same method was applicable to the synthesis of 2‐(morpholino‐U‐14C‐thio)‐benzothiazole using morpholine‐U‐14C as starting material.
Synthesis of tritium and carbon‐14 labeled 4,5‐bis(4‐methoxyphenyl)‐ 2 ‐(trifluoromethyl)thiazole
Authors: Hsi Richard S. P. , Stolle Wayne T.
Published: October 2006

Tritium labeled 4,5‐bis(4‐methoxyphenyl)‐2‐(trifluoromethyl)thiazole (1) was synthesized with the tritium label located on the phenyl ring at the C‐4 position of the thiazole ring and meta to the methoxy group. Anisole specifically labeled with tritium at C‐3 was used to prepare tritium labeled 1 with specific activity of 53 μCi/mg in 53% overall radiochemical yield. The title compound 1 was also labeled with carbon‐14 at the C‐4 position of the thiazole ring. [14C)Barium carbonate was used as the isotope source, and carbon‐14 labeled compound 1 of 31.4 μCi/mg was obtained in 54% overall radiochemical yield. Deuterium and carbon‐13 labeled starting materials and intermediates were used as models for preparing the tritium and carbon‐14 labeled compounds, respectively.
Radiolabelling of poly(butyl 2‐cyanoacrylate) nanoparticles with a technetium‐99m‐dextran complex
Authors: Douglas Stephen J. , Davis Stanley S.
Published: October 2006

Poly(butyl 2‐cyanoacrylate) nanoparticles have been radiolabelled with a 99mTc‐dextran complex to allow their pattern of biodistribution to be followed by using the technique of gamma scintigraphy. The method involves the preforming of a 99mTc‐dextran complex and using this as a polymerie stabiliser during the formation of nanoparticles. Copolymerisation of this complex with the cyanoacrylate monomer results in the radiolabel being covalently linked to the nanoparticle matrix with a labelling efficiency of approximately 18%. The radiolabelled nanoparticles slowly degrade and release the activity into buffer solution. The release rate was relatively unaffected by the presence of plasma proteins indicating that the system should be suitable for use in vivo.
Synthese von (2‐14C)Dihydrojasmonsäure
Authors: Unverricht Alfons , Gross Dieter
Published: October 2006

A short synthesis of (2‐14C)(±)‐dihydrojasmonic acid from 2‐pentyl‐cyclopent‐2‐enone and diethyl (2‐14C)malonate is described.
Marquage par 14C DU S‐Acetyl, N‐Glycylcysteamine (1 102)
Authors: Madelmont J. C. , Moreau M. F. , Godeneche D. , Parry D. , Oiry J. , Imbach J. L.
Published: October 2006

Le trifluoroacetate de S Acetyl N glycyl cystéamine a été marqué par 14C en trois positions

Sur le groupe cystéamine par l'intermédiaire de la 14C 1 benzyloxycarbonyl éthanolarnine.

Sur le carbonyl peptidique par l'intermediaire de la 14C I BOC glycine.

Sur le groupe acétyle en utilisant l'anhydride acétique 14C.
Stereochemistry of reductive dehalogenation with deuterium gas
Authors: Kaspersen Frans M. , Sperling Eric M.
Published: October 2006

The stereochemistry of reductive debromination and deiodination of 4‐haloprolines and 2‐ or 7‐bromo‐cholesterols with 2H2 catalyzed by Pd was investigated using 2H NMR. The reactions are stereoselective but not stereospecific.
Radiolysis of D(+)‐carnitine by 60Co‐γ‐radiation and formation of L(+)‐β‐methylcholine
Authors: Löster Heinz , Strack Erich , Seim Hermann
Published: October 2006

The radiolysis of D(+)‐carnitine by 60Co‐γ‐radiation was examined to obtain optically active β‐methylcholine. It was found that the radio lysis leads to a number of trimethylammonium bases but to no other betaines. The acids formed were not investigated. The bases produced were separated by ion exchange chromatography. (+)‐β‐Methylcholine and acetonyltrimethylammonium could be identified by means of common analytical methods (IR, NMR, MS and MA) applied to the fractions. The amounts of methylamines formed by irradiation, and determined by gas chromatography, were very small. Racemization of the D(+)‐carnitine did not occur during irradiation, L(‐)‐carnitine was not found when an enzymatical determination method was used. The fact that (+)‐β‐methylcholine was formed from D(+)‐carnitine is pharmacologically important, because acetyl‐L(+)‐β‐methylcholine has a strong interaction with muscarinic receptors.
Synthesis of [Carbonyl‐14c] labeled carbonate and carbamate esters
Authors: Nassar Munir N. , Agha Bushra J. , Digenis George A.
Published: October 2006

A two‐step synthesis of three carbonate and four carbamate esters labeled at the carbonyl with carbon‐14 is described. The method utilizes the readily available [14C]‐phosgene which is first converted to an isolable [14C]‐labeled alkyl or aryl chloroformate and subsequently reacted with the appropriate alcohol or amine to give the corresponding ester.
The preparation of ormetoprim labeled with carbon‐14
Authors: Liebman Arnold A. , Bader Gerhard J. , Kaegi Heinz H. , Perry Clark W.
Published: October 2006

The sulfonamide potentiator ormetoprim (6) has been prepared with a carbon‐14 label for use in biological studies. The key intermediate. 2‐methylveratraldehyde (4), was prepared by 14CO2 carbonation of the Grignard reagent from 2‐bromo‐4,5‐dimethoxytoluene (1) followed by esterification. reduction and manganese dioxide oxidation.
Synthese d'Hyoroxy‐3 Anorostene‐5 One‐17 (DHA) Tritiee a Haute Activite Specifique
Authors: Pichat L. , Moustier A. M. , Lellouche J. P. , Beaucourt J. P.
Published: October 2006

Tritiated DHA with a high specific activity is necessary for radioimmunoassays. We synthesized DHA labell with tritium in three positions (Specific Activity: 90 Ci/mM). After protection of the 17‐carbonyl group of the Δ1,4 androstadiene‐3,17 dione, monobromide 3 was obtained. Dehydrobromination and selective reduction with NaBH4 led to the precursor 5 which was reduced by tritium. After deprotection DHA‐[l,2,15‐3H] waw obtained purified by liquid chromatography and characterized by TLC, 3H‐NMR. MS and HPLC. Data concerning U.V. spectra NMR and Optical Rotatory Power are given for the main products and for sidereactions compounds.
Specifically labelled beta‐carbolines for biomedical investigations
Authors: Gynther J. , Huhtikangas A. , Auriola S. , Juvonen H.
Published: October 2006

Five radioactive and three deuterium labelled 1.2,3,4‐tetrahydro‐beta‐carbolines (THBCs) have been synthesized from tryptamine hydrochloride or 5‐methoxytryptamine hydrochloride and formaldehyde, glyoxylic acid or pyruvic acid. Radioactive labelling was performed using [14C] and [3H]labelled compounds. while the deuterium labels were introduced using lithium aluminium deuteride. The specific activities obtained for [14C] labelled THBCs varied between 1.0 and 5.0 mCi/mmol, while a value of 30.1 mCi/mmol was obtained for the tritiated compound. The isotopic purities of the deuterated THBCs were in the range of 76.3 ‐ 96.2 %.
Convenient one‐pot synthesis of benzoquinone‐[U‐14c] and hydroquinone‐[U‐14c]
Authors: Parnes Howard , Dekeczer Steve
Published: October 2006

Benzoguinone‐[U‐14C] was synthesized in 90% yield from benzene‐[U‐14C] via a three step seguence. Conditions were developed which allowed this conversion to be accomplished in a one pot closed system. The benzoquinone‐[U‐14C] thus obtained could be reduced to hydroquinone‐[U‐14C] in quantitative yield. Preparation of benzene‐[U‐14C] is also described.
Synthesis of deuterium‐labeled felbamate from diethyl phenylmalonate
Authors: Choi Yong M. , Kucharczyk Norbert , Sofia R. Duane
Published: October 2006

A synthesis of felbamate‐d4 (2‐phenyl‐1.3‐propanediol‐1,1,3,3‐d4 dicarbamate) starting from diethyl phenylmalonic acid ester and lithium aluminum deuteride was developed. The procedure has three steps from the starting material to felbamate‐d4 via the intermediate. 2‐phenyl‐1,3‐propanediol‐1,1,3,3‐d4. The final overall yield was 44%. The isotope purity was 99.2%.