bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of [3″‐3H]taxol and [13‐3H]taxol1
Authors: Taylor George F. , Thornton Stephen S. , Tallent C. Ray , Kepler John A. 
Published: October 2006

Abstract7‐Trietylsilylbaccatin III (11) was coupled with cis‐1‐benzoyl‐3‐triethylsiloxy‐4‐(3′‐bromophenyl)azetidin‐2‐one. Hydrolysis of the silyl groups gave 3″‐bromotaxol which was reduced with tritium gas to give[3″‐3H]taxol with specific activity of 19.3 Ci mmol. Reduction of 7‐triethylsilyl‐13‐oxobaccatin III with [3H]borane‐tetrahydrofuran complex gave 7‐triethylsilyl[13‐3H]baccatin III (17). Coupling of 17 with cis‐3‐triethylsiloxy‐4‐phenyl‐(3R,4S)‐azetidin‐2‐one and hydrolysis gave [13‐3H]taxol with specific activity of 1.66 Ci/mmol.
Synthèse d'un herbicide tritié à forte activité spécifique: Le Thifensulfuron méthyle
Authors: Bastide J. , Ortega F. 
Published: October 2006

AbstractIn order to study the binding on acetolactate synthase, a tritiated herbicide sulfonylurea (thifensulfuron methyl) of high specific activity was synthesized. By use of C3H3I for esterification of an acid group, a rapid incorporation of tritium into this compound may be achieved.
Synthesis of [18F]fluoroethoxy‐benzovesamicol, a radiotracer for cholinergic neurons
Authors: Mulholland G. Keith , Jung Yong‐Woon , Wieland Donald M. , Kilbourn Michael R. , Kuhl David E. 
Published: October 2006

AbstractFull experimental details are given for the preparation of [18F]fluoroethoxy‐benzovesamicol, (−)‐(2R, 3R)‐trans‐2‐hydroxy‐3‐(4‐phenylpiperidino)‐5‐(2‐[18F]fluoroethoxy)‐1,2,3,4‐tetralin, a new fluorine‐18 labeled cholinergic neuron mapping agent for use in positron emission tomography (PET). This radiotracer was made by nucleophilic radiofluorination of tosyloxyethoxy‐benzovesamicol, followed by reverse phase HPLC purification, in decay corrected radiochemical yield exceeding 60%.
Synthesis of 5‐[123I]iodonicotinamide and biodistribution in rat
Authors: Bergström K. A. , Lötjönen S. , Kuikka J. T. , Penttilä P. , Mussalo H. , Hiltunen J. , Länsimies E. 
Published: October 2006

Abstract5‐[123I] iodonicotinamide (NAM) was prepared by halogen exchange iodination from 5‐bromonicotinamide. In order to study biodistribution and brain accumulation 123I‐NAM was injected into rats. Dynamic gamma camera images were collected. The rats were sacrificed and tissue specific activities were measured. From dynamic images the maximum brain (head) activity after 30 minutes was 8.3% of the injected dose and after 110 minutes, 4.5%. 123I‐NAM was cleared by the kidneys. Radioactivity in the tissue samples of brain, kidney, blood, liver, spleen, lung, muscle, heart, bone and thyroid decreased over the course of 110‐160 minutes, indicating rapid washout of the tracer. In conclusion the uptake in the brain and washout of 123I‐NAM was rapid. 123I‐NAM may be useful as a brain imaging agent.
Synthesis of [3H]‐labelled glucobrassicin, a potential radiotracer for metabolic studies of indole glucosinolates
Authors: Chevolleau S. , Joseph B. , Rollin P. , Tulliez J. 
Published: October 2006

AbstractGlucobrassicin, an indole glucosinolate widespread in cruciferous plants, appears to be involved in anticarcinogenic activity via its breakdown products. In order to study the “in vivo” metabolism of glucobrassicin, we have synthesized the 5‐[3H]‐indol‐3‐ylmethyl glucosinolate (3H‐labelled glucobrassicin) starting from artificial peracetylated 5‐bromoindol‐3‐ylmethyl glucosinolate. The labelled compounds were characterized by radio‐HPLC and FAB mass spectrometry.
Synthesis of (+)‐N‐(6‐Ethoxy[2,4‐3H]phenyl)‐N‐(1,2,2‐trimethylpropyl)‐2‐nitroethene‐1,1‐diamine ([3H]BAY x 9228)
Authors: Pleiß U. , Lenfers J.‐B. , Schmitt P. 
Published: October 2006

AbstractThe synthesis of tritium‐labelled (+)‐N‐(6‐Ethoxy[2,4‐3H]phenyl)‐N‐(1,2,2‐trimethylpropyl)‐2‐nitroethene‐1, 1‐diamine ([3H]BAY x 9228) a pottassium channel opener, was achieved by dehalogenation of a dibrominated racemic precursor using palladium hydroxide on charcoal as catalyst. The separation into the enantiomers was achieved by an chiral HPLC‐column. The specific activity was 47.9 Ci/mmol (1.8 TBq/mmol).
Stereoselective synthesis of [11 β‐3H]prostaglandin E1
Authors: Bundy G. L. , Easter J. A. , Banitt L. S. , Philopoulos Y. , Sinha A. J. Wickrema , Hsi R. S. P. 
Published: October 2006

AbstractThis report describes an efficient stereoselective synthesis of [11β‐3H]prostaglandin E1 ([11β‐3H]PGE1). The key multiply protected 11‐keto intermediate was prepared in only three steps from PGE1. Reduction of the ketone function at C‐11 with sodium borodeuteride and sodium borotritide, followed by sequential removal of protecting groups, afforded PGE1 labeled with deuterium and tritium, respectively, at the 11‐beta position. The reduction and deprotection were accomplished in one reaction flask without requiring purification of intermediates. Trace amounts of C11‐epimer formed in the reduction were readily separated by means of preparative reversed‐phase HPLC. Using sodium borotritide of nominally 67 Ci/mmol, we obtained [11β‐3H]PGE1 with specific activity of 15 Ci/mmol. A disposition study in the monkey with intravenous administration of this material indicated excellent in vivo metabolic stability of the 11β‐tritium label.
Synthesis of 14C‐labelled sodium pariprazole (E3810)
Authors: Tagami Katsuya , Chiku Shigeru , Sohda Shigeru 
Published: October 2006

AbstractSodium pariprazole (E3810), an inhibitory of H+,K+‐ATPase, was synthesized labelled with carbon‐14, starting from 2‐mercapto[2‐14C]‐benzimidazole 1 with a specific activity of 888 MBq/mmol. It was obtained in 49.3% radiochemical yield with a radiochemical purity of more than 98%.
Radiolabelling of pharmaceutical dosage forms by neutron activation of samarium‐152
Authors: Awang M B , Hardy J G , Davis S S , Wilding I R , Parry S J 
Published: October 2006

AbstractSamarium‐152 can be activated in a neutron flux for the labelling of pharmaceutical dosage forms for evaluation by gamma scintigraphy. The samarium is incorporated as samarium oxide powder which is available with 152Sm in its natural isotopic abundance or isotopically enriched. The yield of 153Sm was reduced considerably following the neutron activation of the non‐isotopically enriched oxide. This can be attributed to the high neutron capture by 149Sm present in the non‐isotopically enriched oxide. In order to keep the mass of the added oxide powder to the minimum and also to reduce the neutron irradiation time, it is recommended that samarium oxide enriched with 152Sm should be used routinely when radiolabelling pharmaceutical dosage forms.
Low cost production of perdeuterated biomass using methylotrophic yeasts
Authors: Haon Stéphane , Augé Sophie , Tropis Marielle , Milon Alain , Lindley Nic D. 
Published: October 2006

AbstractThree strains of methylotrophic yeasts, Candida boidinii, Pichia angusta (previously Hansenula polymorpha) and Pichia Pastoris, were studied for their capacity to grow on methanol in deuterated media. Growth rates, determined relative to the extent of deuteration of water and/or methanol, showed that water deuteration was the major limiting factor. After adaptation to deuterium by progressive transfer through media of increasing deuteration, growth rates were diminished relative to those obtained on hydrogenated media of identical salts composition: the two Pichia species retained the highest growth rates (μ=0.02 h−1) in the fully deuterated medium. Perdeuterated biomass (16 g) was obtained in a 1 liter fed‐batch fermentation and the extent of deuteraton of isolated ergosterol has been shown to be 97.5% by mass spectrometric analysis.
C10‐Oe‐N‐(4‐azido‐5‐125iodo salicyloyl)‐β‐alanyl‐β alanyl ryanodine (Az‐βAR), a novel photo‐affinity ligand for the ryanodine binding site
Authors: Bidasee Keshore R. , Besch Henry R. , Kwon Sangyeol , Emmick Jeffrey T. , Besch Kurt T. , Gerzon Koert , Humerickhouse Rod A. 
Published: October 2006

AbstractA high affinity, photoactivatable, radio‐iodinated ligand for the ryanodine binding site(s) of the sarcoplasmic reticulum calcium‐release‐channel, C10‐Oeq‐N‐(4‐azido‐5‐125iodo salicyloyl)‐β‐alanyl‐β‐alanyl ryanodine (Az‐βAR), was synthesized at a specific activity of 1400mCi/mmol. Prepared by condensing the versatile synthon, N‐(4‐azido‐5125iodo salicyloyl)‐β‐alanine with C10‐Oeq‐β‐alanyl ryanodine, Az‐βAR, like [3H] ryanodine, does not demonstrate saturation binding kinetics. 127Az‐βAR exhibits an IC50 of 27.2 ± 2 × 10−9 M (mean ± SD) compared to ryanodine's 6.2 ± 0.4 × 10−9 M for the ryanodine receptor/calcium release channel of sarcoplasmic reticulum vesicles isolated from rabbit skeletal muscle.
Synthesis of a radiotracer for studying σ receptors in vivo using PET: (+)‐N‐[11C]‐benzyl‐N‐normetazocine (1S, 5S,9S‐(+)‐cis‐2‐[11C]‐2′‐hydroxy‐5,9‐dimethyl‐6,7‐benzomorphan)
Authors: Musachio John L. , Mathews William B. , Ravert Hayden T. , Carroll F. Ivy , Dannals Robert F. 
Published: October 2006

Abstract(+)‐N‐[11C]‐Benzyl‐N‐normetazocine (1S,5S,9S‐(+)‐cis‐2‐[11C]‐benzyl‐2′‐hydroxy‐5,9‐dimethyl‐6,7‐benzomorphan), a potent and selective ligand for the σ receptor, was prepared by N‐benzylation of (+)‐cis‐N‐normetazocine with [α‐11C]‐benzyl iodide in ethanol using sodium hydrogen carbonate as the proton acceptor. The radiotracer was purified by semi‐preparative reverse‐phase HPLC. The average specific activity was 746 mCi/μmol calculated at end‐of‐synthesis (EOS). The average time of synthesis including formulation was 35 minutes.
2‐Amino‐2′‐[18F]fluorobenzhydrols, intermediates for the synthesis of [2′‐18F]‐1,4‐benzodiazepine‐2‐ones
Authors: Johnström Peter , Stone‐Elander Sharon 
Published: October 2006

AbstractA method for synthesizing 18F‐labelled 2‐amino‐2′‐fluorobenzhydrols under nocarrier‐added conditions for use as radiolabelled intermediates in the synthesis of[2′‐18F]‐1,4‐benzodiazepine‐2‐ones is presented. Anilinodichloroborane reagents were formed by the reaction of boron trichloride with 4‐chloro‐N‐methylaniline, 6a, 4‐nitro‐N‐methylaniline, 6b, 4‐nitro‐N‐ethylaniline, 6c, and 4‐chloro‐N‐(2,2,2‐trifluoroethyl)aniline, 6d. 2‐[18F]Fluorobenzaldehyde, 5, synthesized in 55–70% yields by the nucleophilic aromatic substitution of 2‐nitrobenzaldehyde with the Kryptofix/K+ complex of [18F]F−, was subsequently reacted with the anilinodichloroborane coupling reagents with aromatic substitution occurring ortho to the amino group. The resulting 2‐amino‐2′‐[18F]fluorobenzhydrols, 7a ‐ 7d, were produced in conversions of 60–95% with reaction time ⩽ 10 min at room temperature or 60°C, depending on the aniline used. The total synthesis time, including evaporation of the target water, was 60–65 min. The total radiochemical conversions were of the order of 50–65% for 7a ‐ 7c and 35–45% for 7d, decay‐corrected and based on [18F]F−.
The synthesis of [10‐13C]bilirubin IXα
Authors: Sturrock E. D. , Bull J. R. , Kirsch R. E. 
Published: October 2006

AbstractThe total synthesis of [10‐13C]bilirubin IXα, the principal waste product of haem degradation, is described. Site specific labelling was accomplished by the Vilsmeier formylation of one of the dipyrrolic fragments using [1‐13C]dimethylformamide. The penultimate dehydrohalogenation reaction was complicated by a competing elimination reaction which yielded a bridged biliverdin derivative. [10‐13C]bilirubin IXα was prepared in an overall yield of 6% (from the step where 13C was introduced) with quantitative isotopic incorporation.
Synthesis of N‐(3‐azido‐4‐chlorophenyl)‐N′‐[3H‐methyl] thiourea, an efficient photoaffinity probe for the urea carrier
Authors: Lamotte Herve , Degeilh Francoise , Neau Philippe , Ripochet Pierre , Rousseau Bernard 
Published: October 2006

AbstractStarting from commercial 4‐chloro‐3‐nitroaniline, through a 5 step synthesis, was prepared 3‐azido‐4‐chlorophenylisothiocyanate 5 which was reacted with [3H]‐methylamine. The latter was obtained by three methods:

[3H]‐LiAlT4 reduction of benzylcarbamate gave rise to [3H]‐methylamine (S.A.: >70 Ci/mmol).
Catalytic reduction of HCN with 3H2 lead to [3H]‐CH3NH2 (S.A.: 0.7 Ci/mmol).
Schmidt rearrangement of [3H]‐sodium acetate gave [3H]‐CH3NH2 (S.A.: 29 Ci/mmol).
Compound 7 at the highest specific activity had a self radiolysis rate precluding its practical use in biological studies whilst 29 Ci/mmol [3H]‐7 was satisfactory.
Tritiation of organic compounds by polymer‐supported acid catalysts
Authors: Brewer J. R. , Jones J. R. , Lawrie K. W. M. , Saunders D. , Simmonds A. 
Published: October 2006

AbstractA range of organic compounds have been tritiated (and in some cases deuteriated) via hydrogen isotope exchange reactions using polymer supported acid catalysts. The extent and regiospecificity of labeling were investigated as a function of substrate and catalyst type. Although all the catalysts were found to be active in the tritiation of both aromatic and heterocyclic compounds, there was clear evidence that the extent of hydrogen isotope exchange was influenced by the nature of the polymer support matrix.
Synthesis of (N‐[11C]methyl)Y‐29794, a competitive inhibitor of prolyl endopeptidase
Authors: Charalambous A. , Mangner T. J. , Kilbourn M. R. 
Published: October 2006

AbstractProlyl endopeptidase (PEP: [E.C.3.4.21.26]) is a widely distributed serine peptidase that cleaves a variety of oligopeptides in the brain and peripheral tissues. Y‐29794 ((2‐(8‐dimethylaminooctylthio)‐6‐isopropyl‐3‐pyridyl‐2‐thienyl ketone) is a potent competitive reversible inhibitor of this enzyme. In order to study the biodistribution of PEP in vivo we have synthesized (N‐[11C]methyl)Y‐29794, by [11C]alkylation of the N‐desmethyl precursor. The radiotracer was purified by silica gel Sep‐Pak and was obtained in 10‐17% yields (EOB: synthesis times shorter than 45 min) with >98% radiochemical purities and specific activities >550 Ci/mmol (EOS).
Preparation of 17‐amino‐22‐(4′‐azido‐3′‐125iodophenacyl)‐17‐demethoxygeldanamycin (1): An ansamycin for photoaffinity labeling
Authors: Schnur Rodney C. , Corman Michael L. 
Published: October 2006

AbstractAn azido‐125iodo‐ansamycin (1) in the geldanamycin family was prepared in two steps in one reacton vessel from 17‐amino‐22‐(4′‐aminophenacyl)‐17‐demethoxygeldanamycin (3). The title compound was suitable for photoaffinity labeling proteins that interacted with ansamycins. A alternative synthesis is reported for preparation of unlabeled title compound in order to afford practical amounts of (1) for conventional biochemical studies.
Synthesis of an [125I]‐labelled derivative of MK‐571, a tool for LTD4 receptor studies
Authors: Li Chun‐Sing , Leblanc Yves , Zamboni Robert , Young Robert N. 
Published: October 2006

AbstractAn [125I]‐labelled derivative of MK‐571 2 was synthesized from the arylstanne derivative 11 in 50% radiochemical yield. Compound 2 is a useful tool for LTD4 receptor studies. The arylstanne intermediate 11 was obtained from the coupling reaction of (±)‐3‐[[[3‐[2‐(7‐chloro‐2‐quinolinyl)‐(E)‐ethenyl]phenyl][[3‐[(3‐aminopropyl)amino]‐3‐oxopropyl]thio]methyl]thio]propionic acid 10 with N‐hydroxysuccinimidyl 4‐trimethylstannylphenylacetate 3. The synthesis of 3 could be easily achieved from 4‐bromophenethyl alcohol.
Synthesis of sodium [11C]thiocyanate using [11C]cyanogen bromide
Authors: Westerberg Göran , Långström Bengt 
Published: October 2006

AbstractA method for the preparation of sodium (11C]thiocyanate from [11C]cyanogen bromide and sodium sulfide is described. Sodium [11C]thiocyanate was obtained in 94% decay‐corrected radiochemical yield with a specific radioactivity of 122 GBq μmol−1 (3.3 Ci μmol−1) in a synthesis time of 21 minutes. The sodium [11C]thiocyanate was used in the synthesis of ethyl‐, isopropyl‐, and benzyl [11C]thiocyanate in 78, 71 and 84% radiochemical yields, respectively.
A new simple synthesis of 1,3‐dideuterated malondialdehyde (3‐hydroxy[1,3‐2H2]‐2‐propenal)
Authors: Allevi Pietro , Anastasia Mario , Ciuffreda Pierangela 
Published: October 2006

AbstractA synthetic route for obtaining 1‐butoxy‐1,3,3‐triethoxy[1,3‐2H2]propane a stable diacetal of the malondialdehyde, is described. The synthesis involves the condensation of deuterated butylvinyl ether with deuterated triethyl orthoformate in the presence of montmorillonite clay K‐10. The deuteration of butyl vinyl ether was accomplished via the intermediary formation of a stannane derivative which was quantitatively metallated by n‐butyllithium and then treated with 2H2O. From the diacetal the 1,3‐dideuterated malondialdehyde was obtained by a short treatment with acid ion exchange resin.
Synthesis of carbon‐14 and tritiated steroidal 5α‐reductase inhibitors
Authors: Shu Arthur Y. L. , Heys J. Richard 
Published: October 2006

Abstract17β‐[N‐(1,1‐Dimethylethyl)carbamoyl]androsta‐3,5‐diene‐4‐14C‐3‐carboxylic acid ([14C]SK&F 105657) was prepared via a three‐step sequence (t‐butyl amidation, triflation and carbomethoxylation) starting from androst‐4‐en‐3‐one‐4‐14C‐17β‐carboxylic acid. Its A‐ring aromatic analog 17β‐[N‐(1,1‐dimethylethyl)carbamoyl]estra‐1,3,5‐(10)‐triene‐3‐carboxylic acid (SK&F 105656) was labeled with tritium by means of iridium‐mediated exchange methodology.
A simple synthesis of 13C6‐labelled flavone and 5‐methoxyflavone
Authors: Ares Jeffrey J. , Wehmeyer Kenneth R. 
Published: October 2006

AbstractThe 13C6‐labelled molecules, flavone and 5‐methoxyflavone, with the carbon‐13 label at all six carbons of the aromatic B ring, have been prepared for use as internal standards in isotope dilution‐mass spectrometry. The key step involves addition of a labelled benzoyl group to the methyl group of a hydroxyacetophenone, forming a 1,3‐diketone. Overall yields from 13C6‐benzoic acid were 38% for the labelled flavone and 45% for the labelled 5‐methoxyflavone.
Synthesis of ethyl ω‐2H5‐docosa‐4, 7, 10, 13, 16, 19‐hexaenoate
Authors: Taber Douglass F. , You Kamfia 
Published: October 2006

AbstractThe preparation and subsequent Wittig reaction of phosphonium salt 4, a useful synthon for the preparation of polyunsaturated fatty acids, are reported. Salt 4 is a key intermediate for the synthesis of ethyl ω‐2H5‐docosa‐4,7,10,13,16,19‐hexaenoate (3).
Radiosynthesis of a new radioiodinated ligand for serotonin‐5HT2‐receptors, a promising tracer for γ‐emission tomography
Authors: Mertens J. , Terriere D. , Sipido V. , Gommeren W. , Janssen P. M. F. , Leysen J. E. 
Published: October 2006

Abstract4‐Amino‐N‐[1‐[3‐(4‐fluorophenoxy)propyl]‐4‐methyl‐4‐piperidinyl]‐2‐methoxy‐benzamide, a compound with high affinity for 5HT2‐receptors, was radioiodinated on the 2‐position of the phenoxygroup or the 5‐position of the methoxybenzamide group. The former (obtained by Cu1+‐assisted radioiodo for bromo exchange) showed high lipophilicity and high non‐specific binding to rat brain tissue both in vitro and in vivo. The second labelled compound, 125I‐4‐amino‐N‐[1‐[3‐(4‐fluorophenoxy)propyl]‐4‐methyl‐4‐piperidinyl]‐5‐iodo‐2‐methoxybenza‐mide, obtained by direct electrophilic substitution, showed high affinity (Kd of 0.11 ± 0.01 nM) and marked selectivity for 5HT2‐receptors in vitro. Moreover in vivo studies in rats over the course of 1‐3 hrs post i.v. injection of the radioactive ligand, showed steady preferential retention of radioactivity in the frontal cortex, which is enriched in 5HT2 receptors. (Frontal cortex (FC) / Cerebellum ratio of 10 and FC / Blood ratio of 6, amount compound / mg tissue).
Synthesis of phenylalanines regiospecifically labelled with deuterium in the aromatic ring
Authors: Nishiyama Kozaburo , Oba Makoto , Ueno Ryuichi , Morita Ayako , Nakamura Yoshikuni , Kainosho Masatsune 
Published: October 2006

AbstractPhenylalanines regiospecifically labelled with deuterium in the aromatic ring can be prepared through the hydrogenolysis of tyrosine tetrazolyl ethers using D2 gas and a medium pressure catalytic hydrogenator.
2‐Octyl‐4H‐1,3,2‐benzodioxaphosphorin 2‐oxide labelled with tritium in the octyl and aryl moieties
Authors: Wu Shao‐Yong , Yoshida Minoru , Casida John E. 
Published: October 2006

Abstract2‐Octyl‐4H‐1,3,2‐benzodioxaphosphorin 2‐oxide (octyl‐BDPO) was labelled with tritium in the 7,8‐octyl and 6‐BDPO positions at specific activities of 38 and 16 Ci/mmol, respectively, by catalytic reductions of the corresponding olefin and bromo precursors with tritium gas. This potent mechanism‐based inhibitor for neuropathy target esterase (NTE) (I50 = 0.25 nM) and delayed neurotoxicant (active in hens at 3 mg/kg) was designed to determine phosphorylated NTE which retains the octyl label and differentiate aging with or without intramolecular group transfer (“alkylation”) reactions at the NTE active site from the fate of the aryl label.
Heterogeneous palladium‐catalyzed exchange labelling of representative organic compounds with tritium gas
Authors: Williams Philip G. , Than Chit , Rabbani Sadegh , Long Mervyn A. , Garnett John L. 
Published: October 2006

AbstractA range of organic substrates was successfully exchanged with tritium gas using NaBH4‐reduced palladium oxide or chloride as catalyst. Exchange conditions involved a reaction temperature of 100 °C, a reaction time of 3 days, and products were analyzed by radio‐gas chromatography and 3H NMR spectroscopy. Both aromatic and aliphatic compounds underwent exchange, 18 of the 22 substrates incorporated > 35% of the available tritium, and most products showed high radiochemical purity. 3H NMR analyses showed that both alkanes and the alkyl chains of alkylbenzenes were rapidly and evenly labelled. Some aromatic compounds showed general ring exchange while others showed high specificity. These results for bulk palladium catalyst are strikingly different from those obtained with bulk platinum and supported palladium catalysts. The results are discussed in terms of currently accepted mechanisms of heterogeneous metal catalyzed hydrogen isotope exchange reactions.
Synthesis of the antiinflammatory prodrug RS‐42169‐14C
Authors: Parnes Howard , Huang Glenn T. 
Published: October 2006

AbstractA facile synthesis of the antiinflammatory agent RS‐42169‐14C, based on a carbonation/cycloaddition sequence is described. The product was obtained in 36% yield from Ba14CO3 at a specific activity of 52 mCi/mmole. The design of the six step sequence was such that pure intermediates were isolated by extractive workup, and only a single chromatographic purification was required.
Synthesis of high specific activity [15,16‐3H2]buprenorphine
Authors: Ötvös Ferenc , Hosztafi Sándor , Simon Csaba , Tóth Géza 
Published: October 2006

AbstractTritium labelling of buprenorphine, a mixed agonist‐antagonist opioid ligand, was performed with a specific activity of 2.35 TBq/mmol (63.6 Ci/mmol) starting with 15,16‐didehydrobuprenorphine. Labels at positions 15 and 16 of the morphine skeleton proved to be sufficiently stable under strong acidic or basic conditions.
Synthesis and 15N NMR spectra of 1‐ and 4‐15N‐2,3,5‐trimethylpyrazines and their N‐oxides
Authors: Maeda Mikiko , Sakuma Chiseko , Kawachi Shinji , Tabei Katsumi , Kerim Ablikim , Kurihara Teruo , Ohta Akihiro 
Published: October 2006

Abstract4‐15N‐2,3,5‐Trimethylpyrazine (1) was synthesized by dechlorination of 4‐15N‐6‐chloro‐2, 3, 5‐trimethylpyrazine (5) the key intermediate, derived from 15N‐DL‐alanine (3).1‐15N‐2,3,5‐Trimethylpyrazine (2) was prepared by decarboxylation of 1‐15N‐2, 3, 5‐trimethyl‐pyrazine‐6‐carboxylic acid (10) obtained by the Pummerer type rearrangement of 1‐15N‐tetramethylpyrazine 1‐oxide (1) followed by oxidation.1‐ And 4‐oxides and 1,4‐dioxides of the above 15Ntrimethylpyrazines were also obtained by treatment with sodium perborate in acetic acid.15N NMR spectra of the compounds thus prepared were measured and the assignment of two 15N signals were certified.