bluuebunny/crossref_metadata_2025_split huggingface dataset:
Production and purification of mixed 14C‐labelled peptides derived from plant biomass
Authors: Ling John R. , Bronwen Cooper P. , Parker Stephen J. , Armstead Ian P. 
Published: October 2006

AbstractProcedures are described for the production and purification of 14C‐labelled peptides of mixed composition, derived from phytomass. Barley seeds (Hordeum vulgare) were germinated and grown in the dark for 6 days. On day 7, the seedlings were exposed to light in a 14CO2 atmosphere for 24 h. The plant leaves were harvested and their water‐soluble 14C‐labelled proteins extracted. These 14C‐proteins were partially digested by sequential incubation with pepsin, α‐chymotrypsin and trypsin. The resulting 14C‐labelled peptides were separated from contaminating amino acids by elution from columns of copper‐Chelex resin, and finally fractionated by gel‐filtration chromatography and assigned to groups according to molecular size. The purified 14C‐peptides ranged in relative molecular mass up to approximately 5,000, possessed a purity in excess of 97%, and were radiolabelled in all amino acid residues with an average specific radioactivity of 450 Bq/μmol. The methods described can be readily adapted to produce not only mixed 14C‐labelled peptides of any required attribute, such as molecular size or ionic charge, but also mixed 14C‐proteins of 14C‐amino acids.
14C‐labeling of a novel anxiolytic agent tandospirone
Authors: Nishioka Kazuhiko , Kanamaru Hiroshi 
Published: October 2006

AbstractN‐[4‐[4‐(2‐Pyrimidinyl)‐1‐piperazinyl]butyl]bicyclo‐[2.2.1]heptane‐2,3‐di‐exo‐carboxyimide dihydrogen citrate (tandospirone), a novel anxiolytic agent, was labeled with carbon‐14 individually at the imido carbonyl group and the pyrimidinyl ring. The synthesis of carbonyl‐labeled tandospirone was achieved according to the scheme shown in Fig. 3. Diels‐Alder reaction of maleic anhydride (2) with cyclopentadiene (3) afforded the endo anhydride (4), which was transformed into the imide (5) by treating with ammonia water. Thermal isomerization of the endo imide (5) and subsequent chromatographic separation gave the pure exo compound (6). Catalytic hydrogenation of 6 followed by alkylation with 1,4‐dibromobutane (8) yielded the bromide (9a). Condensation of 9a with N‐(2‐pyrimidinyl)piperazine (10a) followed by treatment of the resulting disubstituted piperazine (11a) with citric acid afforded [carbonyl‐14C]tandospirone (1a). The overall yield of 1a was 22% from 2.The similar method was applied to the synthesis of pyrimidinyl‐labeled tandospirone as shown in Fig. 4. Condensation of 2‐chloro[2‐14C]pyrimidine (12) with anhydrous piperazine gave the pyrimidinylpiperazine (10b). N‐alkylation of 10b followed by treatment with citric acid afforded [pyrimidinyl‐2‐14C]tandospirone (1b). The overall yield of 1b was 68% from 12.
An enantioselective synthesis of S‐γ‐[(4‐trifluoromethyl)phenoxy]benzenepropanamine‐[3‐14C] hydrochloride, an important metabolite of fluoxetine hydrochloride
Authors: Wheeler William J. 
Published: October 2006

AbstractThe S‐enantiomer of γ‐[(4‐trifluoromethyl)phenoxy]benzenepropanamine‐[3‐14C] hydrochloride has been prepared in eight steps from acetophenone‐[carbonyl‐14C]. The key step in the synthesis involved the enantioselective reduction of R‐2‐chloroacetophenone‐[1‐14C] with (‐)‐diisopinocampheylchloroborane in an 86.5% yield. The chlorohydrin was converted to R‐phenyloxirane‐[1‐14C], which was subsequently converted to the corresponding R‐cyanohydrin by reaction with TMS‐CN/CaO. Borane reduction and arylation, followed by salt formation yielded S‐γ‐[(4‐trifluoromethyl)phenoxy]benzenepropanamine‐[3‐14C] hydrochloride.
Enzymatic synthesis of [methyl‐2H3] creatinine
Authors: Arcelloni C. , Paroni R. , Bonini P. A. , Magni F. , Kienle M. Galli 
Published: October 2006

Abstract2‐Amino‐1,5‐dihydro‐1‐[methyl‐2H3] 4H‐imidazol‐4‐one ([methyl‐2H3] creatinine) was obtained by acidification and heating (120 °C, 120 min) of the [methyl ‐2H3] N‐amidinosarcosine (creatine) synthesised by methylation of guanidoacetate (GA) with S‐adenosyl‐[methyl‐2H3] L‐methionine ([methyl‐2H3] AdoMet) in the presence of rat liver guanidoacetate methyltransferase (GAA‐MT). Isotopic enrichment was 94.7%.
[3H]imidacloprid: Synthesis of a candidate radioligand for the nicotinic acetylcholine receptor
Authors: Latli Bachir , Casida John E. 
Published: October 2006

AbstractImidacloprid is an exceptionally potent insecticide known from physiological studies to act at the nicotinic acetylcholine receptor. To prepare [3H]imidacloprid as a candidate radioligand, 6‐chloronicotinoyl chloride was reduced with NaB2H4 (in model studies) or NaB3H4 in absolute ethanol to 2‐chloro‐5‐pyridinylmethanol which was transformed to 2‐chloro‐5‐chloromethylpyridine on refluxing with thionyl chloride. Coupling with 4,5‐dihydro‐N‐nitro‐1H‐imidazol‐2‐amine then gave [2H2]imidacloprid incorporating about 95% of the deuterium or [3H2]imidacloprid (25 Ci/mmol) in 80% radiochemical yield. In studies not detailed here [3H]imidacloprid was found to undergo high affinity, specific and saturable binding to a site in insect brain.
Tc‐99m‐markierung von cymantren‐analogen verbindungen mit verschiedenen substituenten ‐ ein neuer zugang zu Tc‐99m radiodiagnostika
Authors: Wenzel M. 
Published: October 2006

AbstractThe Technetium‐analogues of Cymantrene derivatives containing different side chains can be labelled with Tc‐99m in a simple manner starting from labelled pertechnetate.For the synthesis a solution of a ferrocene derivative with the wanted side chain, Tc 99m‐pertechnetate and a carbonyl‐donator like Mn(CO)5Br are heated at 150°C in a small glass vessel. There after the labelled cytectrene derivative is separated from by‐products by chromatographic methods. The radiochemical yields are between 15–95%. ‐ Some of the compounds showed a remarkable brain affinity with a high Tc‐99m‐concentration ratio brain/blood.
The synthesis of [14C]BRL 26830a, a novel β‐adrenoceptor agonist
Authors: Freer R. , Morecombe D. J. 
Published: October 2006

AbstractBRL 26850A has been extensively reported 1 as a novel β‐adrenoceptor agonist. In order to perform metabolism studies, carbon‐14 radiolabelled BRL 26830A was synthesised from potassium [14C]cyanide. As BRL 26830A contains two asymmetric centres, the initial product required resolution of the two enantiomeric pairs. This was achieved by sequential fractional crystallisation of the free base and then the hydrobromide salt to obtain the required (R*, R*)‐(+) enantiomeric pair before final conversion to the hemifumarate salt ([14C]BRL 26830A).
Deuteriation of RS 87476
Authors: Souchet Michel , Pascal Jean Claude 
Published: October 2006

AbstractDeuteriation of toluidine in 2H2O and synthesis of N‐[(d5‐phenyl phenyl)methyl] piperazine are described. These intermediates permit the incorporation of 7 deuterium atoms into RS 87476. This efficient synthesis of polydeuterated RS 87476 facilitated its use in preliminary animal studies and as an internal standard in RS 87476 quantification.
A convenient preparation of 3‐[2H3]methyl‐3‐buten‐1‐ol
Authors: Winter Rudolph Ernst K. , Jian Zhigang 
Published: October 2006

AbstractA procedure for the conversion of 3‐hydroxy‐3‐methylglutaric anhydride to methyl 3‐methyl‐3‐butenoate forms the basis for a convenient synthesis of 3‐[2H3]methyl‐3‐buten‐1‐ol.
Synthesis of 2,3‐disubstituted [3‐13C]naphthalenes and [9a‐13C]naphtho[2,3‐d]‐1,2,3‐oxadiazole
Authors: Blocher Achim , Zeller Klaus‐Peter 
Published: October 2006

AbstractThe synthesis of 2‐amino‐2‐hydroxy[3‐13C]naphthalene starting from 2‐(1,3‐dioxolan‐2‐yl)‐benzyl chloride and sodium [13C]cyanide in seven preparative steps is reported. Diazotation of the labelled amino compound followed by deprotonation yields [9a‐13C]naphtho[2,3‐d]‐1,2,3‐oxadiazole. The β‐13C‐labelled naphthalenes prepared are characterized by their 13C‐chemical shifts and 13C13C spin spin coupling constants.
Synthesis of 9‐(2‐phosphonylmethoxy)ethyl‐8‐[14C]adenine [14C]PMEA
Authors: Haynes U. J. , Swigor J. E. , Bronson J. J. 
Published: October 2006

AbstractThe synthesis of [14C] PMEA (3) was achieved by coupling the sodium salt of 8‐[14C]adenine (1) with 2‐(diisopropyl‐phosphonymethoxy) ethanol methanesulfonate in N,N‐dimethylformamide at 100°C to provide the diisopropyl ester (2). Deesterification with bromotrimethylsilane in acetonitrile, followed by concentration and then aqueous hydrolysis of the resulting silylated intermediate produced [14C] PMEA (3) as a crystalline solid having a radiochemical purity of 99.1% and a specific activity of 88.7 μCi/mg in an overall yield of 30%.
Synthesis of [11C]‐ohmefentanyl, a novel, highly potent and selective agonist for opiate μ‐receptors
Authors: Zhu Y. C. , Prenant C. , Crouzel C. , Comar D. , Chi Z. Q. 
Published: October 2006

AbstractThe authors of the present paper reported the synthesis of [11C]‐ohmefentanyl in a symposium abstract in 1991(1). We here describe the results of synthesis and analysis in detail. Ohmefentanyl 1 is a novel, highly potent and selective agonist for opiate μ‐receptors. In order to visualize the μ‐receptor by Positron Emission Tomography (PET), this compound was labelled with carbon‐11. The unlabelled cis‐A‐ohmefentanyl was prepared in a nine‐step synthesis and two‐step fractional crystallization, and the OH‐precursor 11 for [11C]‐ohmefentanyl labelling was obtained by hydrolysis of the 4‐N‐propionyl group of cis‐A‐ohmefentanyl in 6 N hydrochloric acid. The [11C]‐propionyl chloride was prepared by carbonation of ethylmagnesium bromide with cyclotron‐produced [11C]‐carbon dioxide followed by direct treatment of the intermediate complex with phthaloyl dichloride and 2,6‐di‐t‐butylpyridine. Reaction of the OH‐precursor 11 with [11C]‐propionyl chloride yields [11C]‐ohmefentanyl separated by HPLC, with a high specific activity of 11.1 – 14.8 GBq μmol−1 (300−400 mCi μmol−1), 49 minutes after the end of bombardment.The keto‐precursor 12, prepared by hydrolysis of the 4‐N‐propionyl group of cis‐10 in 8 N hydrochloric acid, was also used for [11C]‐ohmefentanyl labelling. Reaction of the [11C]‐propionyl chloride with keto‐precursor 12, followed by addition of sodium borohydride, yields [11C]‐ohmefentanyl.The [11C]‐labelled ohmefentanyl obtained using the OH‐precursor 11 is a cis‐A form, while that obtained using the keto‐precursor is a mixture of cis‐A and cis‐B forms.
The preparation of a 11C‐labelled 5‐lipoxygenase product. 5(S)‐hydroxy‐6(R)‐(N‐[1‐11C]acetyl)cysteinyl‐7,9‐trans‐11,14‐ciseicosatetraenoic acid
Authors: Oberdorfer Franz , Siegel Thilo , Guhlmann Albrecht , Keppler Dietrich , Maier‐Borst Wolfgang 
Published: October 2006

Abstract5(S)‐Hydroxy‐6(R)‐(N‐[1‐11C]acetyl)cysteinyl‐7,9‐trans‐11,14‐cis‐eicosatetraenoic acid (N‐[1‐11C]acetyl leukotriene E4) was prepared by the reaction of leukotriene E4 and [1‐11C]acetyl chloride. The product was obtained with 1.3% yield, based on [1‐11C]acetyl chloride. The preparation required 50 min from the end of radioisotope production. The chemical and radiochemical purity of an injectable dose of N‐[1‐11C]acetyl leukotriene E4 was 95%. The remaining impurities were the 11‐trans isomer primarily and the sulfoxides of 5(S)‐hydroxy‐6(R,S)‐(N‐[1‐11C]acetyl)cysteinyl‐7,9‐trans‐11‐(cis,trans)‐14‐cis‐eicosatetraenoic acid. The stereochemistry of the sulfoxides at C‐6 and at the C‐11 double bond respectively was not identified. The average specific activity of the carrier added preparation was 2 GBq/μmol at the time of application.
Synthesis of [16‐14C]trichodiene the precursor to trichothecenes
Authors: Zamir Lolita O. , Huang Liren 
Published: October 2006

AbstractThe synthesis of radiolabelled trichodiene with 14C at the olefinic methyl (C‐16) is described. The isotope was introduced using a 14C‐Wittig reagent prepared in situ from triphenyl phosphine and 14C‐methyliodide.
A convenient preparation of glycolic‐1‐14C acid
Authors: Clizbe Lane A. , Reist Elmer J. 
Published: October 2006

AbstractAn operationally simple preparation of glycolic‐1‐14C acid from 14CO2 has been developed using a tin‐lithium exchange reaction to generate the required hydroxymethyl anion equivalent. Glycolic‐1‐14C acid was then produced in high yield and good radiochemical purity upon hydrogenolytic removal of the benzyl group.
An improved synthesis of α‐13C glycine and heteronuclear NMR studies of its incorporation into thioredoxin
Authors: Wishart David S. , Sykes Brian D. , Richards Frederic M. 
Published: October 2006

AbstractWe present an improved method to easily prepare gram quantities of α‐13C glycine beginning from K13CN. The four step synthesis involves the production of an N, N‐diphenyl‐cyanoformamidine intermediate through the coupling of cyanide to N, N‐diphenylcarbodiimide. Subsequent reduction by LiAlH4 and hydrolysis of the resulting amidine produces fully enriched α‐13C labelled glycine with a 45‐50% yield. This relatively fast and simple synthesis uses only commonly available compounds and requires no special equipment, making the process easy to perform in any well equipped biochemistry laboratory. We further demonstrate that the product may be used, without extensive purification, to specifically label bacterially expressed proteins (E. coli thioredoxin) through standard biosynthetic procedures. We also show that the 13C glycine‐labelled protein may be readily analyzed using commonly available heteronuclear NMR techniques. Complete assignments for all 9 glycines of native E. coli thioredoxin are presented.
Synthesis of carbon‐14 and tritium labelled analogs of the noval antischizophrenic agent clozapine
Authors: Sunay Ustun B. , Talbot Kenrick C. , Galullo Vincent 
Published: October 2006

Abstract8‐Chlor‐11‐(4‐methyl‐1‐piperazinyl)‐5H‐dibenzo[b,e][1,4]diazepine (SDZ 100‐129, Clozapine) labeled with carbon‐14 in the 11‐position was prepared from 2‐aminobenzonitrile‐[cyano‐14C]. In addition, SDZ 100‐129 was also labeled with C3H3 in the methyl group of the 4‐methyl‐piperazine ring.
Synthesis of 14C‐(carbonyl)‐N‐(4‐iodo‐2,6‐diethylphenylcarbamoylmethyl)‐iminodiacetic acid
Authors: Pozzi Oscar R. , Arciprete Carlos P. , Gros Eduardo G. , Mitta Aldo E. A. 
Published: October 2006

AbstractThe synthesis of the N‐(4‐iodo‐2,6‐diethylphenylcarbamoylmethyl) iminodiacetic acid labelled with 14C at the carbonyl carbon atom which was required for metabolism studies is described. The complex formation between the title product and Tc‐99m is also presented.
Preparation of 13C8 derivatives of naphthalene, octachloronaphthalene and two hexachloronaphthalenes
Authors: Auger P. , Malaiyandi M. , Wightman R. H. , Williams D. T. 
Published: October 2006

AbstractA mild high yield sequence is reported for the synthesis of (13C8) naphthalene from (13C6) benzene and (13C2) succinic acid involving Friedel‐Crafts condensation, Wolff‐Kishner reduction, polyphosphoric acid cycliacylation, sodium borohydride reduction and palladium dehydrogenation. Perchlorination of (13C8) naphthalene gave a good yield of (13C8) octachloronaphthalene from which the (13C8) hexachloronaphthalenes were obtained by zinc/acetic acid reduction.
Synthesis of [3,3‐D2]4‐hydroxy‐1‐(3‐pyridyl)‐1‐butanone, an internal standard for analysis of tobacco‐specific nitrosamine hemoglobin and DNA adducts
Authors: Lin Jyh‐Ming , Amin Shantu , Murphy Sharon E. , Solomon Jerome J. , Hecht Stephen S. 
Published: October 2006

AbstractThe synthesis of [3,3‐D2]4‐hydroxy‐1‐(3‐pyridyl)‐1‐butanone ([3,3‐D2]HPB), an internal standard for the analysis of hemoglobin and DNA adducts of tobacco‐specific nitrosamines, is reported. 3‐Pyridine carboxaldehyde was converted to 2‐(3‐pyridyl)‐1, 3‐dithiane. This was condensed with 2‐(2‐bromoethyl)‐1, 3‐dioxalane to yield 2‐[2‐(3‐pyridyl)‐1, 3‐dithiane]ethyl‐1, 3‐dioxalane. Selective hydroylsis of the aldehyde protecting group produced 4‐(1, 3‐dithian‐2‐yl)‐4‐(3‐pyridyl)‐butanal, which was then labeled with deuterium adjacent to the aldehyde carbonyl group. Reduction with LiAlH4 produced the corresponding alcohol. Removal of the dithianyl protecting group required protection of the alcohol as its t–butyldimethylsilyl ether. Treatment with AgNO3/N‐chlorosuccinimide in aqueous CH3CN produced [3,3‐D2]HPB.
Synthesis and preliminary evaluation of an iodovinyl‐tetrabenazine analog as a marker for the vesicular monoamine transporter
Authors: Canney Daniel J. , Guo Yu‐Zhi , Kung Mei‐Ping , Kung Hank F. 
Published: October 2006

AbstractA derivative of tetrabenazine (TBZ, 1) containing an iodovinyl group (I‐TBZ, 3b) was prepared as a potential radiotracer for the vesicular monoamine transporter. The synthesis of 3a was achieved by ethynylation of TBZ. The ethynyl derivative 4, was converted to the corresponding vinylstannane 5. The vinylstannane intermediate was then treated with I2 in chloroform at room temperature, to afford the iodovinyl compound (3a, I‐TBZ). The no‐carrier‐added [125I]I‐TBZ (3b) was prepared by treating an ethanolic solution of 5 with sodium[125I]iodide in the presence of H2O2. Following i.v. injection, [125I]I‐TBZ (3b) can readily cross the blood brain barrier and localize in the brain (0.92 and 0.36% dose/organ, at 2 min and 30 min, respectively). However, no specific regional uptake of the ligand was observed. Subsequent biodistribution studies performed using two well resolved peaks obtained from chiral HPLC separation of 3b, demonstrated that Fraction I displayed higher brain uptake (0.6% dose/organ, 20 min) than the latter peak (Fraction II, 0.3% dose/organ, 20 min). Fraction I also exhibited a modest degree of specificity for the striatum which could be blocked by pretreatment with tetrabenazine. The high lipophilicity of 3a (Po/b for Fraction 1 and II=1723 and 1395, respectively) may contribute to high nonspecific binding in vivo, and result in the low target/nontarget ratio observed for this compound. Iodovinyl‐TBZ analog 3b is a poor candidate as a SPECT imaging agent for the vesicular monoamine transporter.
True tracer radiolabeling of gadolinium complex of 10‐(2‐hydroxypropyl)‐1,4,7,10‐tetraazacyclododecane‐1,4,7 triacetic acid (HP‐DO3A)
Authors: Kumar Krishan , Sukumaran K. , Chang C. Allen , Tweedle M. F. , Eckelman W. C. 
Published: October 2006

AbstractTrue tracer radiolabeling, purification, and analysis of a gadolinium complex of HP‐DO3A (10‐(2‐hydroxy‐propyl)‐1,4,7,10‐tetraazacyclo dodecane‐1,4,7‐triacetic acid) was achieved by the reaction of carrier‐added 153GdCl3 and excess free ligand. Two analytical methods (ITLC and HPLC) were developed to determine the purity of radiolabeled samples.
The preparation of tritiated E‐ and Z‐4‐aminobut‐2‐enoic acids, conformationally restricted analogues of the inhibitory neurotransmitter 4‐aminobutanoic acid (GABA)
Authors: Duke Rujee K. , Allan Robin D. , Drew Colleen A. , Johnston Graham A. R. , Mewett Kenneth N. , Long Mervyn A. , Than Chit 
Published: October 2006

AbstractA synthesis of [3H]E‐ and [3H]Z‐4‐aminobut‐2‐enoic acids from methyl 4‐N‐phthalimidobut‐2‐ynoate by catalytic hydrogenation using tritium gas in the presence of a homogeneous catalyst, tris(triphenylphosphine)rhodium(I) chloride, is reported. HPLC separation of the E‐ and Z‐isomers, and the saturated analogue, 4‐aminobutanoic acid (GABA), is also described.
Synthesis of novel [14C]‐labelled phenylureas bearing photoactive azido and diazirine groups as photoaffinity labels for the herbicide binding site of photosystem two
Authors: Jewess Philip , Whitelegge Julian P. , Camilleri Patrick , Bowyer John R. 
Published: October 2006

AbstractWe have synthesised two photoaffinity‐labelling hydrophobic stilbene urea inhibitors of Photosystem 2 (PS2) bearing either an azido group (3‐(3‐((E)2‐(4‐azidophenyl)ethenyl)‐phenyl)‐1,1‐dimethylurea, azido‐PDU) or a diazirine group (3‐(3‐((E)2‐(4‐(3‐(trifluoromethyl)‐diazirin‐3‐yl)phenyl)ethenyl)phenyl)‐1,1‐dimethylurea, diazirinyl‐PDU) as well as [14C]‐labelled forms of these compounds. The key step in both syntheses was the formation of the stilbene entity by a Waddsworth‐Emmons reaction of either a trifluoroacetyl‐protected aminobenzaldehyde or a 3‐(trifluoromethyl)‐diazirin‐3‐yl‐substituted benzaldehyde with dimethyl(4‐nitrophenylmethyl)‐phosphonate which gave largely E stereochemistry. The latter compound was made from 4‐bromobenzaldehyde protected as the 1,3 dioxolane. The substituted diazirine was then constructed via Grignard chemistry and an adaptation of a published procedure for the synthesis of diazirines. Reduction of the nitrostilbenes to the respective anilines and conversion to the isocyanates followed by reaction with di[14C]methylamine then gave the required [14C]‐labelled phenylurea photoaffinity reagents. In studies not detailed here both reagents were found to be highly active inhibitors of photosynthetic electron transport before UV irradiation and to covalently label the herbicidebinding protein (D1) of Photosystem 2 after UV treatment. Diazirinyl‐PDU was found to be considerably more sensitive to UV irradiation than azido‐PDU.
Synthesis and spectroscopic characterisation of 3‐chloroperbenzoic acid‐17O,18O, nitrosobenzene‐17O,18O and nitrosobenzene‐15N
Authors: Bleasdale Christine , Ellis Martin K. , Farmer Peter B. , Golding Bernard T. , Handley Kevin F. , Jones Peter , McFarlane William 
Published: October 2006

Abstract3‐Chloroperbenzoic acid‐17O,18O was prepared from 3‐chlorobenzoyl chloride and hydrogen peroxide‐17O,18O (obtained by subjecting water‐17O,18O. Nitrobenzene‐15N was reduced to aniline‐15N, which was oxidised by 3‐chloroperbenzoic acid to nitrosobenzene‐15N. 15N and 17O NMR data are given for the corresponding labelled nitrosobenzene.
Synthesis of 7‐[α‐(2‐amino‐[2‐14C]thiazol‐4‐yl)‐α‐(Z)‐methoxyiminoacetamido]‐3‐(1‐methylpyrrolidinio)methyl‐3‐cephem‐4‐carboxylate hydrochloride ([14C]cefepime hydrochloride)
Authors: Standridge R. T. , Swigor J. E. 
Published: October 2006

AbstractThe title compound 9 was prepared by the route outlined in Scheme I. [14C]Thiourea (1) was condensed with ethyl 4‐bromo‐3‐oxo‐2‐methoxyiminoacetate (2), providing ethyl 2‐(2‐amino‐4‐[2‐14C]thiazolyl)‐2‐methoxyiminoacetate (3), as the pure Z‐isomer. Saponification gave the amino acid 4; this was reacted with 1‐hydroxybenzotriazole to give the activated ester 5. Condensation in situ with 7‐amino‐3‐(1‐methylpyrrolidinio) methyl‐3‐cephem‐4‐carboxylate (6) yielded the product as the pure sulfate salt (7).Treatment of 7 with base provided the zwitterion 8, isolated as the stable N‐methyl‐2‐pyrrolidinone adduct. An aqueous solution of the adduct was converted to the crystalline title compound, [14C]Cefepime hydrochloride hydrate (9), with hydrochloric acid/acetone. Radiochemical purity was 99.0% and specific activity, 34.2 μCi/mg. Overall yield from [14C]thiourea was 18%.
The synthesis and resolution of tritiated 4‐amino‐3‐phenylbutanoic acid ([3H]R‐ and [3H]S‐β‐phenylgaba)
Authors: Duke Rujee K. , Allan Robin D. , Drew Colleen A. , Johnston Graham A. R. , Mewett Kenneth N. , Long Mervyn A. , Than Chit 
Published: October 2006

AbstractA synthesis of [3H]R‐ and [3H]S‐4‐amino‐3‐phenylbutanoic acid ([3H]R‐ and [3H]S‐β‐phenylGABA) from the unsaturated intermediate by catalytic hydrogenation using tritium gas in the presence of palladium on charcoal is reported. The [3H]R‐ and [3H]S‐diastereoisomers of pantolactone ester of β‐phenylGABA were separated by HPLC.
Synthesis of fluoro‐dideutero‐methyl 1,1,1,3,3,3‐hexafluoro‐2‐propyl ether (deuterated sevoflurane)
Authors: Baker Max T. , Chiang Chao‐Kuo , Tinker John H. 
Published: October 2006

AbstractSevoflurane was synthesized with deuterium substituents on the fluoromethoxy carbon. This was performed by a two‐step reaction process that yielded deuterated sevoflurane of high purity.