bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of [14C]methylphosphonic difluoride
Authors: Bechtold W. E. , Dahl A. R.
Published: October 2006

The synthesis of [14C] methylphosphonic difluoride is described. First, [14C]methyl iodide was used to catalyse the conversion of trimethyl phosphite to dimethyl [14C]methylphosphonate by the Arbusov reaction. The dimethyl methylphosphonate was then chlorinated with PCl5 and fluorinated with SbF3. Radiochemical yield from the reaction was 25%.
Synthesis of N‐(2, 5‐[2‐13C]dimethyl‐1H‐pyrrol‐1‐YL)‐6‐(4‐morpholinyl)‐3‐Pyridazinamine hydrochloride
Authors: Mola Nunzio Di , Bellasio Elvio , Ferrari Pietro , Zerilli Luigi F.
Published: October 2006

N‐(2, 5‐[2‐13C]dimethyl‐1H‐pyrrol‐1‐yl)‐6‐(4‐morpholinyl)‐3‐pyridazinamine hydrochloride ([2‐13C]methyl MDL‐899), a new antihypertensive agent, was synthesized for metabolic studies, in five steps via 2, 5‐[1‐13C]hexanedione, and characterized by 1H‐ and 13C‐NMR, IR, and MS.
Tritiated peptides. Part 161. Synthesis of [3H‐Tyr8]‐physalaemin
Authors: Brundish D. E. , Wade R.
Published: October 2006

The title compound was synthesized with a specific activity of 30 Ci mmol−1 and with radiochemical purity of 96% by iodination of the sulphoxide followed by catalytic tritiation of an isolated fraction. Iodination and reduction studies on model peptides are reported. Alternative philosophies for preparing tritiated peptides are critically discussed.
Synthesis of [carbonyl‐14C]‐labelled remoxipride and raclopride. Two potential neuroleptic agents
Authors: Gawell Lars
Published: October 2006

The synthesis of two benzamide derivatives labelled with carbon‐14 at the carboxamide position is described. The radioactive label was introduced by the reaction of 1,3‐dimethoxy‐2‐lithiobenzene with [14C]carbon dioxide to furnish 2,6‐dimethoxy[carboxy‐14C]benzoic acid (2). Halogenation of 2 with dioxane dibromide or sulphuryl chloride followed by reaction with thionyl chloride led to the corresponding labelled acid chlorides. These were reacted with (S)‐2‐(aminomethyl)‐1‐ethylpyrrolidine (5) and converted into [14C]remoxipride (6) and [14C]raclopride (8), respectively.
Synthesis of 75Se‐2‐phenyl‐1,2‐benzisoselenazol‐3(2H)‐one (PZ 51; ebselen. A novel biologically active organo‐selenium compound
Authors: Cantineau R. , Tihange G. , Plenevaux A. , Christiaens L. , Guillaume M. , Welter A. , Dereu N.
Published: October 2006

The preparation of 75Se‐ebselen (75Se‐PZ 51) in a high radiochemical yield (∼40 %) and with a specific activity of 240 mCi/mM (8.9 GBq/mM) is described. It entails a very simple, fast and one‐pot procedure starting from elemental 75Se‐selenium.

75Se‐diselenosalicylic acid 4 is initially prepared as the key intermediate which is transformed into a corresponding dichloride 5‐before reacting with aniline to yield the desired 75Se‐ebselen.

Identity and purity of the labelled compound were controlled by comparison in TLC, HPLC and MS with an authentic sample (1‐2).
Preparation of |2,4‐2H|‐ and |2,4‐3H|‐tomatidine
Authors: Doller D. , Gros E. G.
Published: October 2006

The preparation of |2,4‐2H|‐ and |2,4‐3H|‐tomatidine was accomplished by oxydation of the unlabelled compound to tomatidone, exchange of the labile hydrogens by reaction with H20 and 3H2O on basic alumina and direct reduction of the labelled tomatidone to tomatidine. The efficiency of the procedure was checked by physical (1H and 13C NMR, MS) methods.
Synthesis of psilocin labelled with 14C and 3H
Authors: Poon Grace , Chui Yun‐Cheung , Law Francis C. P.
Published: October 2006

14C‐ and 3H‐Labelled psilocin (4‐hydroxy‐N,N‐dimethyl‐tryptamine), the principal, active agent of hallucinogenic mushrooms, was synthesized from 2‐methyl‐3‐nitrophenol via 4‐benzyloxyindole. 14C‐Labelled potassium cyanide was reacted with 4‐benzyloxygramine (obtained from 4‐benzyloxyindole) to give 14C‐4‐benzyloxy‐3‐indole acetic acid, an intermediate for 14C‐psilocin synthesis. 3H‐Labelled lithium aluminium hydride was used to react with 4‐benzyloxy‐3‐indole‐N,N‐dimethyl‐glyoxylamide (obtained from 4‐benzyloxyindole) to give 3H‐4‐benzyloxy‐psilocin which was debenzylated to form 3H‐psilocin.
Dimethyl 3,3,4,4,.5,.5,6,6‐(2H8)‐6‐methoxycarbonyl‐2‐oxo‐hexanephosphonate, a versatile reagent for the synthesis of deuterated ω‐carboxy prostanoids
Authors: Meese Claus O. , Fürst Otto , Borstel Bernd
Published: October 2006

An efficient preparation of the title compound 1a starting from propargyl alcohol and proceeding via deuterated monomethyl adipate (8a) is described. As demonstrated by the first total synthesis of deuterated ω‐carboxy‐thromboxane B2 (13a), 1a may serve as a versatile starting compound for the synthesis of various ω‐carboxy prostanoic acid metabolites.
Synthesis of isomeric 16,17‐epoxy‐[17‐3H)‐derivatives of 3‐hydroxy and 3‐methoxy‐oestra‐1,3,5(10)‐trienes
Authors: Blackburn G. Michael , Taylor Brian F. , Worrall Andrew F.
Published: October 2006

Deuterium NMR spectroscopy has been used to show that a previously published synthesis of 16α, 17α‐epoxy ‐3‐hydroxy‐[17‐3H]oestra‐1,3,5(10)‐triene is not regiospecific but leads to additional isotope incorporation at positions ‐2 and/or ‐4. A modified synthesis is described which leads to the title compounds exclusively labelled at position ‐17.
Syntheses of [5‐2H]‐uracil, [5‐2H]‐cytosine, [6‐2H]‐uracil and [6‐2H]‐cytosine
Authors: Kiritani Reiko , Asano Takeyoshi , Fujita Shin‐Ichi , Dohmaru Takaaki , Kawanishi Tetsuro
Published: October 2006

Facile syntheses of [5‐2H]‐, [6‐2H]‐uracil and [5‐2H]‐, [6‐2H]‐cytosine were investigated. The catalytic reaction of uracil or cytosine with 2H2 gas in alkaline media gave rise to [6‐2H]‐compounds almost exclusively. On the other hand,the reaction of 5‐bromouracil or 5‐bromocytosine with 2H2 gas and gave rise to a mixture of [5‐2H]‐, [6‐2H]‐ and [5‐2H,6‐2H]‐compounds depending on the experimental conditions. By controlling the temperature, the pressure of 2H2 gas and the amounts of catalyst, [5‐2H]‐uracil and [5‐2H]‐cytosine were obtained. The isotopic distribution in each product was measured by 1H NMR spectroscopy combined with an HPLC method.
Separation and formation of ryanodine from dehydroryanodine. Preparation of tritium‐labeled ryanodine
Authors: Sutko John L. , Thompson Lorri J. , Schlatterer Robert G. , Lattanzio Frank A. , Fairhurst Allan S. , Campbell Carlton , Martin Stephen F. , Deslongehamps Pierre , Ruest Luc , Taylor David R.
Published: October 2006

The commercially available preparation of the naturally occurring diterpene ester ryanodine contains several compounds in addition to ryanodine. In the present study these compounds were separated and purified using high performance liquid chromatography. The two major components, ryanodine and dehydroryanodine represented 90% of the material present. A method for the efficient reduction of dehydroryanodine to ryanodine was developed and used to produce ryanodine having tritium atoms at positions 19 and 20 and a specific activity of 60.8 Ci/mmole.
Synthese d'un Derive du Methomyl Marque au 14C avec une Photoaffinite Potentielle Pour le Site Recepteur des Mitochondries Texas
Authors: Aranda G. , Herbert M. , Pichat L.
Published: October 2006

SYNTHESIS OF A LABELLED DERIVATIVE OF METHOMYL WITH POTENTIAL AFFINITY FOR THE BIOLOGICAL ACTIVE SITE OF MITOCHONDRIAS TEXAS

The Grignard reagent from 1‐chloro‐4‐methoxy butane was carbonated with 14CO2 giving [carboxyl14C]‐5‐methoxy pentanoic acid Yield: 80%. Specfic activity : 24,3 mCi/mmole Treated with dry hydrogen bromide in acetic acid, the latter gave [carboxyl 14C]‐5‐bromopentanoic. acid with was condesed with diphenylphosphoryl azide leading to 5‐bromobutyl [carbonyl 14C] isocyanatc. Without isolation, the latter was reacted with methylthioacetoxy giving [carbonyl 14C) S‐methyl‐N [(4‐azidobutyl. carbamoyl) oxy] thivacetimidate with an overall yield of 15,7 %/14CO2 and a radiochemical purity of 99,8 %. Specific activity : 23,7 mCi/mmole.
Preparation and purification of 7‐Iodoclonazepam for use in Radioimmunoassay
Authors: Goddard C P , Law B , Mason P A , Stead A H
Published: October 2006

A method is described for the preparation and purification of 7‐[125I]‐Iodoclonazepam (5‐(o‐Chlorophenyl)‐2, 3‐Dihydro‐7‐[125I]‐Iodo‐1H‐1,4‐Benzodiazepin‐2‐one). The structure was confirmed by mass spectrometry using 7‐[127I]iodoclonazepam prepared by the same method. 7‐[125I]‐Iodoclonazepam binds well to a benzodiazepine antiserum. Although readily displaced by all the benzodiazepines commercially available in the UK, it is not displaced by structurally related nonbenzodiazepines except at very high concentrations. 7‐[125I]Iodoclonazepam should therefore be useful for the development of a screening radioimmunoassay (RIA) for benzodiazepines.
Preparation of [2H]‐paraformaldehyde
Authors: Ouzounian Joseph G. , Anet Frank A. L.
Published: October 2006

Polymeric [2H]‐formaldehyde, which is useful for the synthesis of a variety of labelled molecules, is prepared from bromoform in four steps. The isotopic purity of the final product depends on that of the [2H]‐bromoform made in the first step, and is measured after conversion of the [2H] formaldehyde to [2‐2H]‐5,5‐dimethyl‐1,3‐dioxane.
Regio‐controlled synthesis of 4α‐(3H3}methyl‐5α‐cholestan‐3β‐ol
Authors: Ekhato I. Victor , Robinson Cecil H.
Published: October 2006

4α‐(3H3)Methyl‐5α‐cholestan‐3β‐ol was regioselectively prepared from 5α‐cholest‐1‐en‐3‐one via alkylation with methyl iodide, hydrogenation, and LAH reduction. Details of this synthesis are given. The final and intermediate products were characterised by spectroscopic methods.
Synthesis and purification of 14C N‐2‐hydroxyethyl‐N‐nitrosourea
Authors: Perez G. , Possagno E. , Caponecchi G. , Lilla E. , Polcaro C.
Published: October 2006

14C N‐2‐hydroxyethyl‐N‐nitrosourea was prepared at a specific activity of 30 mCi/mmol and 1.29 mCi/mmol by a two‐step synthetic sequence using 14C ethanolamine as the labelled precursor. Its purification was performed by HPLC using a Lichrosorb‐DIOL column eluted by ethyl ether. The overall radiochemical yield was 10%.
Synthesis of carbon‐14 labeled doxylamine succinate
Authors: Rao Pemmaraju Narasimha , Damodaran Kalyani M.
Published: October 2006

Doxylamine succinate, N,N‐dimethyl‐2‐[1 ‐phenyl‐1‐(2‐pyridinyl)‐ethoxy]ethanamine succinate is an antihistamine used primarily as a sedative. Carbon‐14 labeled doxylamine succinate, required for toxicological studies, was synthesized in two steps starting from 2‐benzoyl pyridine.
Synthese, resolution Optique et Radiolyse d'Acides amines A haute Activite Specifique: L‐Ornithine (3H‐3,4,5,5). L‐Arginine (3H‐3,4,5,5). Acide dl‐Glutamique (3H‐3,4) ET Acide dl‐Glutamique (3H‐3,4,4)
Authors: Ego D. , Beaucourt J. P. , Pichat L.
Published: October 2006

Ethyl 2‐acetylamino‐2‐carbethoxy‐4‐cyano‐3‐butene oate : 3 was prepared by condensation of trans‐1‐bromo‐2‐cyanoethylene : 2 with ethyl sodio acetamidomalonate. 3 was catalytically reduced with tritium followed by hydrolysis giving rise to (3,4,5,5‐3H) DL ornithine 5 spec. act. 103 Ci/mM. L‐ornithine 6 was isolated by preparative reversed phase HPLC on a chiral phase. From 5,(3,4,5,5‐3H) DL arginine spec. activity : 90 Ci/mM was prepared by guanidation and the l (+) enantiomer isolated by preparative HPLC.

Selective catalytic tritiation of 3 in presence of tris (triphenylphosphine) Rh followed by hydrolysis gave [3,4‐3H] DL‐glutamic acid spec. activit 60 Ci/mM. [3,4,4‐3H] DL‐glutamic acid spec. activity 90 Ci/mM was also obtained by catalytic tritiation of compound 15 followed by hydrolysis. 3H–NMR analyses were carried out in each ease. Observations on the self radiolysis under various storage conditions are reported.
Synthesis of 1‐hydroxy‐3‐[3‐3H‐(4‐chlorophenyl)‐2‐piperidone. Labelling of a new antiinflammatory hydroxamic acid
Authors: Bovy P. H. , Callaeri M. , Gillet C. , De Decker J. M. , Winand M.
Published: October 2006

Compound 1, synthezized as a potential topical antiinflammatory agent, has been labelled with tritium on the benzene ring in a position neighboring a chlorine atom. An iodinated precursor was prepared by an original six‐step synthesis. Selective catalytic iodine‐tritium replacement was achieved under mild reaction conditions.
Synthesis and Isotope ratio analysis of methyl nitrite‐15N
Authors: Magalhães Alberto M. T. , Chalk Phillip M.
Published: October 2006

Methyl nitrite‐15N was synthesised on a 0.1 mole scale by the esterification of methanol by aqueous H15NO2. The method is simple and efficient, and provides analytically pure CH3O15NO. A method for determining the 15N enrichment of CH3O15NO is described.
Multiple tritium labelling of (+)‐7‐chloro‐8‐hydroxy‐1‐phenyl‐3‐methyl‐2,3,4,5‐tetrahydro‐1hZ‐3‐benzazepine (sch23390)
Authors: Wyrick Steven D. , McDougald Darryl L. , Mallman Richard B.
Published: October 2006

We previously reported the synthesis of the antidopaminergic‐antipsychotic agent SCH23390 labelled with tritium In the 9 position of the benzazepine ring system at a specific activity of 5.6 Ci/mmole as the racemic mixture. Here, we report the preparation of the higher specific activity (+)‐Isomer of SCH23390 labelled with tritium In both aromatic rings as well as the N‐methyl group. Multiple labelling was achieved by reductive debromination with carrier‐free tritium gas of a dibrominated N‐normethyl derivative over 5% Pd/C and subsequent N‐methylatlon with high specific activity methyl Iodide. The specific activity obtained for the Nor‐SCH23390 was 8.8 Ci/mmole and 93.8 Ci/mmole for the SCH23390.
Syntheses of deuterated methyl 9,15‐octadecadienoate and methyl 9,12,15‐octadecatrienoate geometric isomers
Authors: Rakoff Henry
Published: October 2006

Methyl 9,15‐octadecadienoate‐6,7‐d2 isomers (12) were obtained by Wittig coupling between methyl 9‐oxononanoate‐6,7‐d2 (6) and 6‐nonenyltriphenylphosphonium bromide (11). Compound 11 was prepared from methyl 6‐nonenoate (8) by reduction‐With sodium bis(2‐methoxyethoxy)aluminum‐hydride, bromination with triphenylphosphine dibromide and further reaction with triphenylphosphine. Synthesis of compound 8 was achieved by Wittig coupling between propyltriphenylphosphonium bromide (7) and methyl 6‐oxohexanoate (1) which was obtained by ozonolysis of cyclohexene. Compound 6 was prepared through the dimethoxy derivative from methyl 8‐dioxanyloctanoate‐6,7‐d2 (4) which was obtained by deuteration of methyl 8‐dioxanyloctanoate‐6,7‐d2(4) which was obtained by deuteration of methyl 8‐dloxanyl‐6‐octenoate (3) with tris(triphenylphosphine)chlororhodium and deuterium gas. Compound 3 was obtained from compound 1 by chain extension with [2‐(1,3‐dioxan‐2‐yl)ethyl]triphenylphosphonium bromide (2). Chain extension of 6 with 2 yielded methyl 11‐dioxanyl‐9‐undecenoate‐6,7‐d2(13). The latter was converted to methyl 12‐oxo‐9‐dodecenoate‐6,7‐d2 (15) which was treated with 3‐hexenyltriphenylphosphonium bromide (16) and butyl lithium to give methyl 9,12,15‐octadecatrienoate isomers (17). Geometric isomers formed during each of the Wittig reactions were separated by silver resin chromatography.
Synthesis of [3‐11C]phenylpyruvic acid and its use in an enzymatic transamination to [3‐11C]phenylalanine
Authors: Halldin Christer , Längström Bengt
Published: October 2006

The synthesis of [3‐11C]phenylpyruvic acid, starting with 11CO2, is reported. This α‐keto acid was prepared via a condensation reaction, using [11C]benzaldehyde (prepared as described elsewhere), and 2‐phenyl‐5‐oxazolone, using diazabicyclooctane (DABCO) as a base. The condensation product, [α‐11C]‐4‐benzylidene‐2‐phenyl‐5‐oxazolone, was converted by basic hydrolysis to give [3‐11C]phenylpyruvic acid in 40 % radiochemical yield, starting with 11CO2, within 40 min. The potential of [3‐11C]phenylpyruvic acid in enzymatic transamination, catalyzed by glutamic/oxaloacetic acid transaminase (GOT) (Ee 2.6.1.1) immobilized on CNBr‐activated Sepharose was also studied.
6,7‐Dimethoxy‐4‐(4′‐Amino‐3′[125I]Iodobenzyl) isoquinoline: An isoquinoline receptor probe
Authors: Servin Alain L. , Christinaki Hélène , Viel Claude
Published: October 2006

Isoquinoline derivative, 6,7‐dimethoxy‐4‐{4′‐aminobenzyl)Isoquinoline (DMABI) is synthetized The lodinated derivative 125I‐DMABI of high specific activity( 2175 Ci/mmol ) labelled by Chloramine T method is seperated from the unlabelled precursor by LH 20 chromatography and the probe is test by its capacity to bind to rat intestinal membranes in vitro.

Our results show that the 125I‐DMABI Is a useful tool for characterizing the Isoquinoline Intestinal binding site.
Synthesis of [3H]zolpidem
Authors: Allen John , Parent Ginette , Tizot André
Published: October 2006

Zolpidem is a novel hypnotic agent possessing a substituted imidazo[1,2‐a] pyridine structure. The synthesis of the tritium labelled compound with a specific activity of 60.5 Ci/mmol is described. This new radioligand was initially used to establish and characterize the binding properties of Zolpidem in the rat brain.
Synthesis of a radiobrominated analog of SCH 23390, a selfctive dopamine D1/DA1 antagonist
Authors: De Jesus Onofre T. , Van Hoffaert Glenn J. , Glock Dana , Goldber Leon I. , Friedman Arnold H.
Published: October 2006

A radiobrominated analog of SCH 23390, a selective dopamine D1/DA1 antagonist was prepared. Radiochemical yields of up to 60% were obtained within 15 minutes reaction at room temperature. The synthesis was validated by performing both physical (NMR and mass spectroscopy) and biological tests on the product. Preliminary studies suggest that 75Br‐labelled SCH 23390 analog would be a useful ligand for the studies of CNS dopamine D1 receptors by positron emission tomography.
Synthesis of tritium labelled (−)‐3‐PPP, a selective dopamine autoreceptor agonist
Authors: Thorberg Seth‐Olov , Johansson Lars , Gawell Lars , Sahlberg Christer
Published: October 2006

3H‐(‐)‐3‐PPP (11, (S)‐3‐(3‐Hydroxyphenyl)‐N‐propyl‐[3,4‐3H]piperidine) was prepared by hydrogenation of compound 3, with tritium gas followed by resolution of the racemic mixture. The incorporation of tritium was verified by tritium NMR spectroscopy. Also described is the synthesis and NMR interpretation of two isomeric unsaturated tetrahydropyridine derivatives i.e. compounds 8 and 10.
Labeled bile acids VI: [22,23,24‐13C3]‐methyl 3α,7α‐diacetoxy 5β‐cholan‐24‐oate, [22,23,24‐13c3]‐methyl 3β‐acetoxychol‐5‐en‐24‐oate, and [16,17,22,23‐3h4]‐methyl 3β‐acetoxychol‐5‐en‐24‐oate (1)
Authors: Lai Chee Kong , Byon Chang Yon , Anderson Warren G. , Gut Marcel
Published: October 2006

A general short procedure for the introduction of 13C to the side chain of bile acids is described. Suitable (Z)‐pregn‐17(20)‐enes are key intermediates, while the isotope is introduced by an ene reaction with [1,2,3‐13C3]‐methyl propiolate. For the labeling with tritium, the unlabeled product of the ene synthesis, a Δ5,16,22‐triene was saturated selectively at 16,17 and 22,23 with tritium gas.
14C‐Labelling of prallethrin SF, (4S)‐1‐OXO‐2‐propargyl‐3‐methylcyclopent‐2‐en‐4‐yl (1R)‐CIS‐ and (1R)‐trans‐chrysanthemates
Authors: Kanamaru Hiroshi , Kawahara Kazuo , Kamada Takeshi , Yoshitake Akira , Nakatsuka Iwao
Published: October 2006

Both of the components of prallethrin SF [(4S)‐1‐oxo‐2‐propargyl‐3‐methylcyclopent‐2‐en‐4‐yl (1R)‐cis,trans‐chrysanthemate], a novel potent insecticidal pyrethroid, were labelled with carbon‐14 at the cyclopentenyl‐2 position for use in metabolic studies. Carbonation of 2‐lithio‐5‐methylfuran (4) with carbon‐14 dioxide (3) gave 5‐methyl‐2‐[carboxyl‐14C]furoic acid (5). Reduction of 5 with lithium aluminium hydride followed by oxidation with manganese dioxide afforded 5‐methyl[carbonyl‐14C]‐furfural (7). Modified Grignard reaction of 7 with propargyl bromide and magnesium in the presence of mercuric chloride yielded 1‐(5‐methyl‐2‐furyl)[1‐14C]but‐3‐yn‐1‐ol (8). Molecular rearrangement of 8 followed by isomerization afforded 2‐propargyl‐3‐methyl[2‐14C]cyclopent‐2‐en‐4‐ol‐1‐one (9) in 30% yield from barium [14C]carbonate (2). Direct optical‐resolution of 9 by preparative HPLC with a chiral‐phase column gave (+)‐(4S) and (‐)‐(4R) isomers (10 and 11) quantitatively. Condensation of 10 with (1R)‐cis‐ or (1R)‐trans‐chrysanthemoyl chloride (12a or 12b) yielded (4S),(1R)‐cis‐ or (4S),(1R)‐trans‐[cyclopentenyl‐2‐14C]prallethrin (1a or 1b). Both overall radiochemical yields of 1a and 1b were about 9% from 2.
A nine‐step synthesis of [14C]flupirtine maleate labeled in the pyridine ring
Authors: Choi Yong M. , Kucharczyk Norbert , Sofia R. Duane
Published: October 2006

A nine‐step procedure for microscale synthesis of ethyl 2‐amino‐6‐{[(4‐fluorophenyl)methyl]amino}‐3‐pyridinyl‐2,6‐14C carbamate maleate [10], [14C]flupirtine maleate, was developed. The synthesis started with the readily avaiable and economical reagents, potassium cyanide‐14C and 1,3‐dibromopropane making the following intermediates: glutaronitrile‐14C [2], glutarimide‐14C [3], 2,6‐dichloropyridine‐2,6‐14C [4], 2,6‐dichloro‐3‐nitro‐pyridine‐2,6‐14C [5], 2‐amino‐3‐nitro‐6‐chloropyridine‐2,6‐14C [6], 2‐amino‐3‐nitro‐6‐(p‐fluorobenzylamino)pyridine‐2,6‐14C [7], 2,3‐diamino‐6‐(p‐fluoro‐benzylamino)pyridine‐2,6‐14C [8], and ethyl 2‐amino‐6‐{[4‐fluoropheny(l)‐methyl]amino}‐3‐pyridinyl‐2,6‐14C carbamic acid ester hydrochloride [9]. The overall yield was 6.3% (5.4 mCi), and the radioactivity was 99.8% as determined by high performance liquid chromatogrphy and liquid scintillation counting.
Preparation of carbon‐14, tritium and deuterium labelled terodiline, and carbon‐14 and deuterium labelled emepronium bromide
Authors: Werner Tom F. , Olsson Lars‐Inge
Published: October 2006

Selectively ring‐labelled terodilines (N‐tert‐butyl‐1‐methyl‐3,3‐diphenylpropylamine; 1) were prepared by homogeneous catalytic exchange of aromatic hydrogens for 3H and 2H. In addition, terodilines specifically labelled with 14C, 3H or 2H were prepared from the appropriate 1‐methyl labelled 4,4‐diphenylbutan‐2‐ol, by treating the corresponding tosylates with tert‐butylamine.

Emepronium bromide (N‐ethyl‐N,N,1‐trimethyl‐3,3‐diphenylpropylammonium bromide; 2) specifically labelled with 14C or 2H were similarly prepared by treating the labelled tosylates with N‐ethylmethylamine or dimethylamine, followed by quaternization with methyl bromide or ethyl bromide, respectively.
An improved synthesis of 14C labelled glycerol using sodium borohydride
Authors: Chander Harish , Ramamurthy T. T. , Viswanathan K. K.
Published: October 2006

[1‐14C]Glyceric acid has been reduced to [13]‐14Clglycerol in high yields via the methyl ester of 1‐14Clglyceric acid by sodium borohydride in the presence of t‐butyl alcohol and methanol. The importance of the procedure is highlighted in relation to other procedures involving lithium aluminium hydride reduction.
Syntheses of no‐carrier‐added (NCA) [18F]fluoroalkyl halides and their application in the syntheses of [18F]fluoroalkyl derivatives of neurotransmitter receptor active compounds
Authors: Shiue C.‐Y. , Bai L.‐Q. , Teng R.‐R. , Wolf A. P.
Published: October 2006

Nucleophilic aliphatic substitution of alkyl halides, 1, [(CH2)nX2 (n=2, 3; X=Br,I)], with NCA K[18F]/Kryptofix 2.2.2 in CH3CN gave the corresponding NCA [18F]fluoroalkyl halides 2 in 30–40% yields. The factors which influence the yield of 2 were compared. N‐Alkylation of several neurotransmitter receptor active amides and amines with this reagent gave the corresponding NCA N‐[18F]fluoroalkyl derivatives (3–6) in 20–60% yield.
Synthesis of racemic [3‐11C]‐labelled alanine, 2‐aminobutyric acid, norvaline, norleucine, leucine and phenylalanine and preparation of L‐[3‐11C]alanine and L‐[3‐11C]phenylalanine
Authors: Antoni Gunnar , Långström Bengt
Published: October 2006

The syntheses of racemic [3‐11C]‐labelled alanine, 2‐amino‐butyric acid, norvaline, norleucine, leucine and phenyl‐alanine are reported. The reaction were performed by a phase‐transfer alkylation reaction on N‐(diphenylmethylene)‐glycine tert‐butyl ester with the appropriate 11C‐alkyl iodides followed by acidic hydrolysis and the labelled amino acids were obtained in 10‐55 % radiochemical yield. L‐[3‐11C]‐Alanine and L‐[3‐11C]phenylalanine were obtained in 99 % enantiomeric excess after treatment of the corresponding racemic mixture by D‐amino acid oxidase immobilized on glutaral‐dehyde‐activated glass beads.

In a typical run starting with 120 mCi [11C]carbon dioxide, 25 mCi [1‐11C]benzyl iodide was prepared and used to give 6 mCi of DL‐[3‐11C]phenylalanine within 50 minutes. Following treatment with D‐amino acid oxidase, 0.3 mCi of L‐[3‐11C]phenylalanine was obtained after a total synthesis time of about 100 minutes.
Nuclear overhauser effects in tritium nmr
Authors: Kaspersen Frans M. , Funke Carel W. , Sperling Eric M. G. , Wagenaars Gerard N.
Published: October 2006

The accuracy of the quantification of the tritium distribution in labelled compounds may be reduced by differential nuclear Overhauser effects, especially for compounds in which the different tritiated positions differ in the number of protons surrounding them.
Synthesis of 1‐C2H3 theophylline and 3‐C2H3 theophylline
Authors: Berlioz C. , Falconnet J. J. , Desage M. , Brazier J. J.
Published: October 2006

This article describes a three step‐selective deuteration method of 1‐methyl and 3‐methylxanthine, after protection of the N‐7 position by chloromethylpivalate and alkylation by trideuteromethyl iodide; yielding 1‐C2H3 and 3‐C2H3 theophylline.
Synthesis of 2H8‐leukotriene B4
Authors: Dawson Michael , Vine John H. , Forrest Michael J. , McGee Colette M. , Brooks Peter M. , Watson Thomas R.
Published: October 2006

A semi‐synthetic method for the preparation of deuterated leukotriene B4 (2H8‐LTB4) from eicosatetraynoic acid (ETYA) is described which involves reduction of ETYA to deuterated arachidonic acid (2H8‐AA) with deuterium gas and then biological conversion of this material to 2H8‐LTB4 by rat peritoneal polymorphonuclear leukocytes (PMNs).
The preparation of 3‐phenoxy[1‐14C]‐ and 3‐phenoxy[3‐14C]propene
Authors: Kupczyk‐Subotkowska Lidia , Shine Henry J
Published: October 2006

Preparations of specifically labeled α‐ and γ‐[14C]allyl phenyl ether are described.
Synthesis of 1‐(2‐ethoxyethyl)‐2‐(4‐methyl‐1‐homopiperazinyl)‐[2‐14C]benzimidazole difumarate([14C]KB‐2413)
Authors: Awata Norio , Satomi Osamu
Published: October 2006

1‐(2‐Ethoxyethyl)‐2‐(4‐methyl‐1‐homopiperazinyl)‐[2‐14C]‐benzimidazole difumarate ([14C]KB‐2413), a new antihistaminic agent, was prepared from labelled urea.

The synthetic intermediate, 1‐(2‐Ethoxyethyl)benzimidazolone, obtained in good yield by the condensation of N‐(2‐ethoxyethyl)‐o‐pheynylenediamine with [14C]urea, was chlorinated with phosphorus oxychloride and followed by the reaction with N‐methylhomopiperazine to give the base of [14C]KB‐2413. It was then converted to the difumarate, which was obtained in an overall radiochemical yield of 74% starting from [14C] urea.

The specific activity was 54.4 mCi/mmol and its radiochemical purity was 98.0% in reverse isotope dilution analysis.
Preparation of [Thienyl‐3‐14C]temocillin
Authors: Freer R. , Hatt B. B. , Mitchell M. M. , Morecombe D. D.
Published: October 2006

[thienyl‐3‐14C]Temocillin has been prepared from [1‐14C]chloroacetic acid via 3‐[3‐14C]thienylmalonic acid.
Synthesis of (5,6)‐epoxy‐(1α, 2β, 3α, 4β)‐(±)‐5‐cyclohexane‐ 1‐3H, 2,3, 4‐3H ‐tetrol. (3H ‐Conduritol B epoxide)
Authors: Gal Andrew E. , Voorstad Josée P.
Published: October 2006

Tritium labeled Conduritol B epoxide was prepared by a six step synthesis, starting with p‐benzoquinone. The tritium was introduced into the molecule in the second step by reducing the quinone with sodium boro 3H hydride.
Synthesis of deuterium labelled triazolobenzodiazepines
Authors: Koves G. J.
Published: October 2006

Alprazolam and Triazolam ‐ anxyolitic and hypnotic agents ‐ were labelled with deuterium. First synthesis: through CD3COOD acylation of the appropriate Hydrazones, followed by thermal cyclization. Second synthesis: deuterium exchange through acid catalized carbocation intermediates in a CD3COOD/D2SO4 mixture. The products were used as internal standards for GC/MS/SIM quantitative analysis in forensic case work.
6‐Bis‐(2‐chloroethyl)amino‐6‐deoxy‐D‐[14C(U)]‐glucose
Authors: Thomas H. Jeanette , Montgomery John A.
Published: October 2006

14C‐Labeled 6‐bis‐(2‐chloroethyl)amino‐6‐deoxy‐D‐glucose hydrochloride was prepared from D‐[14C(U)]‐glucose for DNA binding studies.
Preparation of [3H]N, N‐dimethylaniline by microwave discharge activation of tritium gas. Absence of ring saturation
Authors: Peng C. T. , Ding S. F. , Hua R. R.
Published: October 2006

[3H]N, N‐Dimethylaniline was prepared from N, N‐dimethylaniline by tritium labeling by microwave discharge activation of tritium gas; the product was formed without any ring saturated side products. High specific activity and high yield were achieved by input of high microwave power to excite the plasma and by dispersion of substrate on silica‐alumina pellets to increase the contact surface with tritium gas. Circulation or no circulation of tritium gas during labeling did not effect the yield or the specific activity. Dispersion on supported Ni caused an increase in the specific activity of [3H],N, N‐dimethylaniline than on plain silica‐alumina. The lack of ring saturation in N, N‐dimethylaniline in contrast to complete ring saturation in N, N‐dimethylaniline in contrast to complete ring saturation in benzene and benzoic acid has been interpretated to indicate the involvement of tritium ions in addition to tritium atoms in tritium labeling.
Synthesis of cis‐diamino‐[1,1‐[1‐14C]cyclobutanedicarbonyloxy (2)‐0,0] platinum II
Authors: Haynes U. U. , Swigor J. J. , Pittman K. K.
Published: October 2006

The synthesis of the title compound (4) is described. [2‐14C]Diethyl malonate was treated simultaneously with a freshly prepared solution of sodium ethoxide and 1,3‐dibromopropane to give 1 1‐[1‐14C]cyclobutanedicarboxylic acid diethyl ester (1). Treatment with potassium hydroxide saponified the ester leaving the dipotassium salt (2). Conversion of potassium tetrachloroplatinate II with potassium iodide followed by ammonium hydroxide resulted in cis‐diamino‐diiodoplatinum II1 (3). Reaction of (3) with 1,1‐[1‐14C]cyclobutanedicarboxylic acid dipotassium salt in the pressence of silver nitrate resulted in the title compound (4).
The synthesis of carbon‐14 labeled 1‐(4,8‐dimethyl‐8‐methoxynonyl)‐4‐(1‐methylethyl)benzene
Authors: Aguinaga Guillermo M. , Dinizo Stephen E.
Published: October 2006

The title compound, uniformly labeled with carbon‐14 in the benzene ring, was prepared by Wittig reaction of 4‐isopropyl‐benzaldehyde‐14C ring (U) with 3,7‐dimethyl‐7‐methoxyoctylidene‐tripehylphosphrane followed by catalytic hydrogenation of the resulting mixture of olefins. A second route to the title compound, based on alkyllithium chemistry, was demonstrated using unlabeled intermediates. Attempted preparation of the title compound via the Horner‐Emmons modification of the Wittig reaction was unsuccessful.
Preparation of methyl 8c,11c‐eicosadienoate‐17,17,18,18‐d4, methyl 8c,11c,14c‐eicosatrienoate‐17,17,18,18‐d4 and methyl 5c,8c,11c‐eicosatrienoate‐17,17,18,18‐d4
Authors: Adlof R. O. , Emken E. A.
Published: October 2006

Methyl 8c,11c‐eicosadienoate, methyl 5c,8c,11c‐eicosatrienoate and methyl 8c,11c,14c‐eicosatrienoate (all 17,17,18,18‐d4) were prepared in multi‐gram quantities for human metabolism studies. The deuterium atoms were incorporated by reduction of the appropriate acetylenic tetrahydropyranyl (THP) ethers with (Ph3P)3RhCl and deuterium gas. The THP ethers were converted to the iodides with H3PO4/P2O5/KI. The deuterium‐labelled fatty acid methyl esters were then synthesized from the alkyl iodide‐d4 via a series of acetylenic coupling reactions with the last double bond generated by the Witting reaction. Acetylenic bonds were reduced to olefinic bonds by use of Lindlar's catalyst. Both 8,11‐20:2 and 5,8,11‐20:3 were synthesized from the same 8‐carbon‐d4 starting fragment. The 8,11‐20:2 isomer was prepared in a 10‐step synthesis in 19% overall yield, the 5,8,11‐20:3 in 12 steps (18% overall yield) and the 8,11,14‐20:3 isomer in 12 steps with an overall yield of 10%. Trans isomers were removed by silver resin chromatography. The 8,11‐20:2, 5,8,11‐20:3 and 8,11,14‐20:3 compounds had isotopic purities of 91‐97%.
Syntheses of model oligosaccharides of biological significance. 8. A synthesis of a specifically deuterated 2‐propyl 3,6‐DI‐O‐[α‐D‐mannopyranosyl]‐β‐D‐mannopyranoside
Authors: Dime David S. , Rachaman Eliezer , Dime Charles E. , Grey Arthur A. , Carver Jeremy P. , Krepinsky Jiri J.
Published: October 2006

The title trisaccharide has been synthesized containing a 3‐deuterated central mannopyranosyl unit and 2,3,4,6,6′‐pentadeuterio mannopyranosyl units in both arms. 2‐Propyl 2‐O‐benzyl‐4,6‐O‐benzylidene‐3‐deuterio‐β‐D‐ mannopyranoside was obtained by stereoselective deuteride reduction of the corresponding 3‐oxo derivative and was reacted with 2,3,4,6,6′‐penta‐deuterio‐α‐D‐mannopyranosyl bromide. The disaccharide obtained was glycosylated with another equivalent of the same bromide after hydrolysis of the benzylidene group. This sequence led to the title compound after deblocking of all the hydroxyl groups. The 2,3,4,6,6′‐pentadeuterio mannopyranosyl bromide was obtained by a reaction sequence starting with a controlled deuterium exchange in deuterium oxide over Reney nickel catalyst of methylα‐D‐manno‐pyranoside, followed by acetolysis and purification via the corresponding ortheoster. The latter compound gave the bromide on reaction with trimethylesily bromid.
Synthesis of methyl 3‐oxo‐4,4‐dimethylpentanoate‐1,3‐14C
Authors: Sieving Paul
Published: October 2006

A description of the preparation of methyl 3‐oxo‐4,4‐dimethylpentanoate‐1,3‐14C. The Grignard reagent prepared from 2‐chloro‐2‐methylpropane is carbonated with 14CO2 and the resulting trimethylacetic acid treated with methyllithium. 3,3‐Dimethyl‐2‐butanone is treated with NaNH2, the resulting enolate is carbonated with 14CO2, and this ketoacid treated immediately after workup with excess diazomethane.
Synthesis of oxygen‐18 isotope labeled amino acids and dipeptides and its effects on carbon‐13 NMR
Authors: Ponnusamy E. , Jones C. C. , Fiat D.
Published: October 2006

Oxygen‐18 isotope labeled at the carboxyl group of glycine, L‐alanine and L‐proline were synthesized by acid catalyzed exchange or acid hydrolysis of respective methyl ester derivatives of amino acids in HC1/H218O. Quantitative enrichment of glycine was achieved by the acid hydrolysis of amino acetonitrile in H218O. In order to conserve the isotopic enrichment [18O] dipeptides were synthesized by solid phase method. [18O] isotope effects on [13C] NMR of carboxylic carbon of amino acids and carbonyl carbon of peptides was observed. The [18O] isotopic shifts observed for the carboxylic carbon of singly and doubly [18O] labeled amino acids showed that the [18O] isotope effect is additive.
Synthesis of 2R, 4′R, 8′R‐α‐tocopherols selectively labelled with deuterium
Authors: Ingold K. K. , Hughes L. , Slaby M. , Burton G. G.
Published: October 2006

Nine deuterium‐labelled α‐tocopherols having the natural, 2R,4′R,8′R, stereochemistry have been synthesized for study by 2H NMR of the orientation and dynamics of natural α‐tocopherol in a phospholipid bilayer.
A new route to [5α,6α‐3H]androst‐16‐en‐3‐one
Authors: Rómer J. , Wagner H.
Published: October 2006

A new simple synthesis of the boar pheromone [5α, 6α‐3H]‐androst‐16‐en‐3‐one with a specific activity of about 50 Ci/mmol and a radiochemical purity >99% is described.
Synthesis of 1‐14C‐(1S, 4S)‐N‐methyl‐4‐(3,4‐dichlophenyl)‐1,2,3,4‐tetrahydro‐1‐naphthalenamine L‐mandelate (1‐14C‐sertraline mandelate)
Authors: Welch Willard M. , Viveiros Dawn M.
Published: October 2006

The preparation of the title compound, a selective 5‐HT uptake blocker with potential antidepressant properties in man, is described. The labelled material with a specific activity of 0.7 mCi/mmol, was synthesized in 7 steps from K14CN in 6.5% radiochemical yield.
Synthesis of glycolic acid‐1‐14C of high specific activity a facile method of conversion of traces of alkali cyanide‐14C
Authors: Ramamurthy T. V. , Viswanathan K. V.
Published: October 2006

A simple procedure is described which efficiently converts traces of 14C labelled cyanide present as a dilute solution into glycolic acid‐1‐14C with more than 85% radiochemical recovery and of high specific activity.
Synthesis of 14C‐labelled DDD isomers of high specific activity
Authors: Lindholm Ann , Klasson‐Wehler Eva , Wehler Thomas , Bergman Ake
Published: October 2006

Three major DDD isomers, o,p'‐DDD, m,p'‐DDD and p,p'‐DDD, 14C‐labelled in the para‐chlorophenyl ring, have been synthesized. The DDD products were obtained in isotopic yields ranging from 42% to 58% and were of high specific activities; 31 mCi/mmol (o,p'‐DDD; m,p'‐DDD) and 19,8 mCi/mmol (p,p'‐DDD). A minor amount of 14C‐labelled o,m'‐DDD was also isolated. 400 MHz 1H NMR data of the three major DDD isomers and o,m'‐DDD were obtained.
The preparation of a carbon‐11 labelled analgesic — [N‐methyl‐11C]meptazinol
Authors: Turton David R. , Luthra Sajinder K. , Pike Victor W. , Kensett Malcolm J.
Published: October 2006

A procedure for labelling the novel analgesic, meptazinol [(+)1‐methyl‐3‐ethyl‐3‐(m‐hydroxyphenyl)tetrahydroazepine], with the positron‐emitting radionuclide, carbon‐11 (t1/2 = 20.4 min) has been developed in order to permit the pharmacokinetics of this analgesic to be studied in man. The procedure involves the reaction of [11C]iodomethane, itself produced from cyclotron‐produced [11C]carbon dioxide, with normeptazinol in ethanol at 100°C for 5 min, evaporation of any unreacted [11C]iodomethane, purification by HPLC and removal of solvent. Subsequent solubilisation of the radioactive product in ethanol plus isotonic saline and sterilisation by filtration produces a safely‐injectable solution of [N‐methyl‐11C]meptazinol in 14% radiochemical yield (from cyclotron‐produced [11C]carbon dioxide, decay‐corrected). The specific activity of the product is up to 7.4 GBq/μmol at the end of radiosynthesis (40 min from the end of radionuclide production). Preparations have been shown to be radiochemically pure and to be free of normeptazinol by analytical HPLC and TLC. That the radioactive product is [N‐methyl‐11C]meptazinol has been unequivocally demonstrated by co‐inclusion of 13C‐enriched iodomethane in the radiosynthesis and examination of the product by broad‐band proton‐decoupled Fourier transform 13C‐NMR spectroscopy.
Synthesis of iodine‐125 labeled phorbol ester‐a useful gamma‐emitting analog of 12‐o‐tetradecanoylphorbol‐13‐acetate
Authors: Mishra Nrusingha C. , Estensen Richard D. , Abdel‐Monem Mahmoud M.
Published: October 2006

Iodine‐125 labeled analog of 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) was obtained by heating the iodine substituted analog of TPA in acetone with sodium [125I] iodide. The iodine substituted analog of TPA, 12‐O‐(12′‐iodododecanoyl)phorbol‐13‐acetate (IPA), was synthesized from phorbol by a three step reaction sequence. The structure of IPA was confirmed by high resolution proton magnetic resonance, fast atom bombardment mass spectrometry (FAB) and chemical ionization mass spectrometry (CIMS).

The [125I]‐IPA was purified by normal phase flash column chromatography. The product had 99% radiochemical purity and specific activity of Ca. 2.7Ci/mmol.
Synthesis of [6‐2H] and [6‐3H]fecapentaene‐12
Authors: Kassaee Mohamad Z. , Kingston David G. I.
Published: October 2006

The title compounds (6 and 9) were prepared by exchange of the α‐protons of (E,E)‐2,4,‐heptadienyldiphenylphosphine oxide (2) with either 2H2O or 3H2O, followed by condensations with (E,E)‐5‐[2,3‐bis(t‐butyldimethylsilyl) oxy]‐propoxy‐2,4‐pentadienal (4) and deprotection.
Carrier‐free astatination of steroid hormones
Authors: Pillai K. K. R. , McLaughlin W. W. , Lambrecht R. R. , Bloomer W. W.
Published: October 2006

The alpha emitting radiohalogen 211At has potential use as a radiotherapeutic agent when linked to biologically active molecules. The range of compounds which may be astatinated is limited by relative lack of knowledge of organoastatine syntheses. The production of astatovinyl steroids was carried out via electrophilic substitution of tri‐n‐butylstannylvinyl steroids with astatide in the presence of mild oxidizing agents. The astatinated steroids are synthesized rapidly and in carrier‐free fashion yielding compounds of high radiochemical purity.
No‐carrier‐added radiobromination via the gattermann reaction. — Synthesis of 75Br‐ and 77Br‐bromperidol —
Authors: Suehiro Makiko , Yokoi Fuji , Nozaki Tadashi , Iwamoto Masako
Published: October 2006

The Gattermann reaction was applied to the no‐carrier‐added radiobromination of bromperidol. The synthesis with diazotized precursor, no‐carrier‐added 75Br‐ or 77Br‐, and copper powder proved to give the radiobrominated neuroleptic drug in high radiochemical yield of 60 ‐ 70%, and in high specific activity (∼5 Ci/umole). The radiobromination also proved to be regioselective. In the reaction, the copper catalyst was observed to play an important role.

Formation of unlabeled by‐products due to stable chlorine or bromine contamination in the reaction mixture was also studied by neutron activation analysis. Removal of such undesirable halogen nuclides and separation of the unavoidably‐formed chlorinated coupound from the radiobrominated bromperidol is discussed.
An improved synthesis of [15N] 16‐doxyl stearic acid
Authors: Joseph Joy , Lai Ching‐San
Published: October 2006

An improved method for the synthesis of [15N] 16‐Doxyl stearate, a fatty‐acid spin label, is reported. The method requires only one mole of [15N] 2‐amino‐2‐methyl propanol per mole of methyl keto stearate with an overall yield of about 50%. In contrast, the previous method produced only 1‐3% yield. The great improvement in yield was achieved mainly through the reduction of reaction volume which increases the reaction rate by the law of mass action.
Synthesis of 14C‐labeled 3‐{[1‐ethoxycarbonyl‐3‐phenyl‐(1S)‐phenyl‐(1S)‐propyl]amino}‐2,3,4,5‐tetrahydro‐2‐oxo‐1H‐1‐(3S)‐benzazepine‐1‐acetic acid hydrochloride ([14C]CGS 14824A)
Authors: Chaudhuri Naba K. , Patera Russell , Markus Bohdan , Sung Ming‐Sang
Published: October 2006

The title compound, CGS 14824A, was synthesized with a 14C‐label in the azepine ring in 14 steps starting with 1‐bromo‐3‐phenylpropane (1) and K14CN in an overall yield of 1.31%. The reaction of 1 with K14CN yielded the nitrile 2 which upon hydrolysis followed by ring closure gave α‐tetralone‐1‐14C (4). Bromination of 4 followed by oxime formation gave the bromo oxime 5, which upon Beckmann rearrangement by acid treatment yielded the ring expansion product 6. The bromine atom of 6 was then replaced by an azido group, and an acetic ester side chain was introduced at the nitrogen atom. Catalytic reduction of the azido compound 8 gave a mixture of epimeric amino esters which was resolved by salt formation with L‐tartaric acid. The negatively rotating isomer was then reacted with 4‐phenyl‐2‐oxo‐butanoate in presence of sodium cyanoborohydride to give a mixture of diastereoisomers which were separated as their benzyl esters by chromatography. The major isomer was then converted to labeled CGS 14824A.
Synthesis of deuterated optically active verapamil and gallopamil, and of N‐13C‐methyl‐verapamil
Authors: Theodore Louis J. , Nelson Wendel L.
Published: October 2006

Deuterated (‐)‐verapamil, (2S)‐(‐)‐2‐(2,5,6‐2H3‐3,4‐dimethoxyphenyl)‐2‐isopropyl‐5‐[(2,5,6‐2H3‐3,4‐dimethoxyphenethyl)methylamino]valeronitrile, and its analog (‐)‐2H5‐gallopamil, (2S)‐(‐)‐2‐(2,6‐2H2‐3,4,5‐trimethoxyphenyl)‐2‐isopropyl‐5‐[(2,5,6‐2H3‐3,4‐dimethoxyphenethyl)methylamino]valeronitrile, were prepared. (‐)‐Gallopamil readily incorporated five atoms of deuterium into the available positions in the aromatic rings. (‐)‐2H6‐Verapamil was prepared from ring trideuterated 3,4‐dimethoxyphenylacetic acid and (2S)‐(+)‐triphenyl‐methoxy‐2‐[(methanesulfonyl)oxy]propane. Three additional atoms of deuterium were incorporated into the aromatic ring of the N‐methyl‐3,4‐dimethoxyphenethylamine moiety incorporated as the the short N‐alkyl side chain. N‐13C‐Methylverapamil was prepared from N‐13C‐methyl‐3,4‐dimethoxyphenethylamine.
Synthesis of 14C‐labeled perfluorooctanoic and perfluorodecanoic acids; purification of perfluorodecanoic acid
Authors: Reich Ieva L. , Reich Hans J. , Menahan Lawrence A. , Peterson Richard E.
Published: October 2006

Perfluoro‐n‐octaboic acid (PFOA) and perfluoro‐n‐decanoic acid (PFDA), two widely used industrial products, have been synthesized with 14C‐labeling in the C‐1 position. The carboxyl labeled materials were prepared in 48% and 53% yield by carbonation of perfluoroheptyllithium and perfluorononyllithium at −100°C. An efficient chemical method for purification of PFDA was also developed. Treatment of commercial PFDA with refluxing potassium hydroxide solution resulted in removal of the mono and diprotio impurities to give 99% pure PFDA.
Synthesis of deuterium labelled penicillamine and its use for the assignment of the 1H NMR spectra of two cyclic enkephalin analogs
Authors: Mosberg Henry I. , Omnaas John R. , Ramalingam Kondareddiar , Woodard Ronald W.
Published: October 2006

The synthesis of D,L‐[4,4′‐2H6]penicillamine (D,L‐[2H6]Pen) and its incorporation into the cyclic, disulfide‐containing peptides, [D‐Pen2,D‐[2H6]Pen5]enkephalin (DPDPE) and [D‐Pen2,L‐[2H6]Pen5]enkephalin (DPLPE), both highly δ opioid receptor‐selective analogs, are described. The deuterium‐labelled peptides allowed the assignment of the four Pen methyl group resonances in each of the corresponding unlabelled peptides to specific Pen residues.
Synthesis of DL‐[7‐14C]indospicine and DL‐2‐amino[7‐14C]pimelic acid
Authors: Wieczorkowska Elzbieta , Hegarty Mervyn P.
Published: October 2006

A new method of synthesis of DL‐[7‐14C]indospicine and DL‐2‐amino‐[7‐14C]pimelic acid and their nonradioactive equivalents is reported. The combined radiochemical yield of both compounds, starting from potassium [14C]cyanide was 15.3%. Indospicine was isolated as the flavianate.
Preparation of tritium‐labeled diosgenin, esmilagenin and tigogenin
Authors: Rabinowitz Joseph L. , Juarez‐Oropeza  , Zagoya Juan C. Diaz
Published: October 2006

The synthesis of 3H ‐diosgenin, 3H ‐esmilagenin and 3H ‐tigogenin (three potential hypocholesterolemic agents) was accomplished by low pressure hydrogenation of commercial (Sigma D 1634) diosgenin with 3H ‐gas. The mixture of 3H materials obtained was separated by silica gel G‐60 column chromatography by use of a benzene: ethyl acetate (8:2 v/v) solution. Purification of each sapogenin was by TLC chromatography.
Preparation of [3H]‐prazosin
Authors: Dezhu Wu , Xiuzhen Qi , Chunfang Hou , Yading Sun
Published: October 2006

The synthesis of the bromoprazosin, in which bromination and acylation of furoic acid were completed by means of very simple method was described. The reductive catalyzed debromination with tritium gas afforded the (3H)‐prazosin. Its specific activity and radiochemical purity were 22.6 Ci/mmol and 98% respectively.
Preparation of carbon 14‐labelled “Spy Dust” 5‐(4‐nitrophenyl)‐2,4‐[5‐14C]pentadienal, (NPPD)
Authors: Brown Susan I. , Rotert Gary A. , Lamontagne Maurice P.
Published: October 2006

Preparation of carbon 14‐labelled “Spy Dust”, 5‐(4‐nitrophenyl)‐2,4‐[5‐14C]pentadienal is described. The facile synthesis of 4‐nitro[formyl‐14C]benzaldehyde from 1‐iodo‐4‐nitrobenzene by reaction with K14CN/CuCN, followed by reduction with diisobutylaluminum hydride provided this key intermediate in 50% yield. Subsequent treatment with the resonance‐stabilized ylide, formylmethylenetriphenylphosphorane, afforded the title compound.