bluuebunny/crossref_metadata_2025_split huggingface dataset:
The synthesis of deuterium labelled metabolites of warfarin and phenprocoumon
Authors: Heimark L. D. , Toon S. , Low L. K. , Swinney D. C. , Trager W. F. 
Published: October 2006

AbstractThe synthesis of deuterium labelled 4′‐,6‐,7‐ and 8‐hydroxy metabolites of warfarin and phenprocoumon is described. The pentadeuterio labelled 6‐,7‐ and 8‐hydroxyphenprocoumons were prepared via alkylation of the respective 6‐, 7‐ and 8‐methoxy‐4‐hydroxycoumarins with 1‐(phenyl‐d5)‐1‐bromopropane and subaequent cleavage of the methyl protecting group with boron tribromide. The synthesis of 1‐(pentadeuteriophenyl)‐1‐bromopropane and the 6‐, 7‐ and 8‐methoxy‐4‐hydroxy‐coumarins are also presented. The pentadeuterio labelled 6‐, 7‐ and 8‐hydroxy‐warfarins were obtained by reaction of 4‐(phenyl‐d5)‐3‐buten‐2‐one with the respective 6‐, 7‐ and 8‐hydroxy‐4‐hydroxycoumarins in methanol followed by hydrolysis of the intermediate cyclic methyl ketals in aqueous acid. 4‐Hydroxycoumarin‐5,6,7,8‐d4, prepared from phenyl‐d6 and tetradeuteriomalonic acid, was reacted with 1‐(p‐hydroxyphenyl)‐1‐propanol and 4‐(p‐hydroxyphenyl)‐3‐buten‐2‐one to yield labelled 4′‐hydroxyphenprocoumon and 4′‐hydroxywarfarin respectively.
Synthesis of deuterium labelled ibuprofen
Authors: Capponi Vincent J. , Halstead Gordon W. , Theis Donald L. 
Published: October 2006

AbstractThe preparations of [ar‐2H4]‐ibuprofen and [ar, 3,3,3‐2H7]‐ibuprofen are described. The deuterium was incorporated into the aromatic ring of [ar‐2H4]‐ibuprofen which is a metabolically stable Position. [ar,3,3,3‐2H7]‐ibuprofen was synthesized by the same route using [2H3]‐CH3I instead of CH3I for use as a GC/MS internal standard in stable isotope labelled bioavailability studies.
Synthesis of deuterated eicosanoids
Authors: Meese Claus O. 
Published: October 2006

AbstractDeuterated lipoxygenase and cyclooxygenase derivatives of eicosatetraenoic acid (arachidonic acid) and their metabolites are indispensable tools for organic trace analysis, biomedical studies, and mechanistic investigations on the corresponding endogenous (unlabelled) eicosanoids. Methods for the preparation of deuterated eicosanoids are reviewed.
Synthesis of 2,5‐dihydroxy[carboxy‐14C]benzoic acid for electrochemical protein modification
Authors: John Varghese , Vennerstrom Jonathan L. , Holmes Thomas J. 
Published: October 2006

AbstractThe synthesis of 2,5‐dihydroxy[carboxy‐14C]benzoic acid (gentisic acid) is described. The procedure utilized [carboxy‐14C]salicylic acid as a starting material. Salicylic acid was converted to gentisic acid using potassium persulfate hydroxylation. The mixture of hydroxylation products in this reaction was easily separated by UV‐visualized quartz column chromatography to obtain the desired isomer in high purity (overall yield of 38%). This procedure may be used for micro and semimicro preparation of the title compound.
Synthesis of carbon‐14‐labeled sodium palmoxirate and its coenzyme a ester
Authors: Weaner Larry E. , Hoerr David C. 
Published: October 2006

AbstractSynthetic procedures for the preparation of carbon‐14‐labeled sodium palmoxirate (TDGA), labeled either in the carboxyl position or in the tetradecyl hydrocarbon chain, are described. In addition, the synthesis of the coenzyme A ester of TDGA‐14C with a specific activity of 51 mCi/mmol is reported. The coenzyme A ester was prepared by formation of the acyl chloride with oxalyl chloride followed by reaction with coenzyme A (CoA) in a borate‐buffered tetrahydrofuran solution. Purification methods and analytical and stability data are reported for the compounds.
Synthesis of tritium‐labelled cembrene‐A
Authors: Singh Ambarish K. , Prestwich Glenn D. 
Published: October 2006

AbstractThe synthesis of [16‐3H]‐cembrene‐A from unlabelled cembrene‐A is achieved in four steps via selective hydroboration‐oxidation of the isopropenyl double bond, borotritide reduction of the 16‐aldehyde, and o‐nitroselenoxide elimination to regenerate the labelled olefin. This sequence is of general utility in labelling polyisoprenoid hydrocarbons for metabolic studies. Cembrene‐A is a putative intermediate in the conversion of geranylgeranyl pyrophosphate to the polycyclic trinervitane and kempane diterpenes of nasute termite soldiers.
Synthesis of tritium labeled pramiracetam (CI‐879; N‐[2‐[bis(1‐methylethyl)amino]ethyl]‐2‐oxo‐1‐pyrrolidineacetamide)
Authors: Dodd J. H. , Hershenson F. M. , Hicks J. L. , Butler D. E. , Lewis E. P. , Huang C. C. 
Published: October 2006

AbstractPramiracetam (CI‐879; N‐[2[bis(1‐methylethyl)amino]ethyl]‐2‐oxo‐1‐pyrrolidineacetamide) was radiolabeled with tritium. Catalytic reduction of ethyl 2,5‐dihydro‐2‐oxo‐lH‐pyrrole‐1‐acetate in the presence of Pd/C gave ethyl 2‐oxo‐1‐[3,4‐3H]pyrrolidineacetate. Treatment of the tritiated ester with N,N‐bis(1‐methylethyl)‐1,2‐ethanediamine gave pramiracetam, which was subsequently converted to the corresponding sulfate salt.
Synthesis of 1,1,3,3‐(2h4)‐4‐hydroxydebrisoquine sulphate
Authors: Meese Claus O. 
Published: October 2006

AbstractAn efficient synthesis of the analytically useful title compound 2c (1,1,3,3‐(2H4)‐4‐hydroxydebrisoquine sulphate), utilizing a two‐step deuteration(1H/2H exchange of 3‐nitromethylphthalide,4, and LiAl2H4 reduction of 3,3‐(2H2)‐4‐hydroxy‐1,2,3,4‐tetrahydro‐isoquinolin‐1‐one, 6), is described.
Preparation of N.C.A. [17‐18F]‐fluoroheptadecanoic acid in high yields via aminopolyether supported, nucleophilic fluorination
Authors: Coenen Heinrich Hubert , Schüller Manfred , Stöcklin Gerhard , Klatte Bernd , Knöchel Arndt 
Published: October 2006

AbstractA macrocyclic aminopolyether (Kryptofix®2.2.2.) supported labelling method for the preparation of n.c.a. [17‐18F]‐ fluoroheptadecanoic acid is described. The equimolar complex of potassium carbonate and the aminopolyether ([2.2.2./K]+2;CO32‐) is used to provide 18F‐fluoride of high nucleophilicity in a homogeneous solution of acetonitrile. Nucleophilic 18F‐for‐Br substitution in the methylester of 17‐bromoheptadecanoic acid is accomplished with radiochemical yields of 94 + 3%. Subsequent quantitative ester hydrolysis with KOH leads to a simple “one pot” procedure. Minimization of reagent concentrations allows a direct isolation of the product from the reaction mixture by means of reverse phase HPLC. The corrected radiochemical yield of high activity level routine production is 82 + 2% after 90 minutes of synthesis time. The specific activity is > 10,000 Ci/mmol.
Preparation of no‐carrier‐added 4‐[131i]iodoantipyrine using chloramine‐T
Authors: Boothe Thomas E. , Finn Ronald D. , Vora Manhar M. , Kothari J Paresh , Emran Ali M. 
Published: October 2006

AbstractThe blood flow reagent 4‐iodoantipyrine, labelled with 131I or 125I, was prepared by allowing aqueous antipyrine to react with either no‐carrier‐added 131I−I or 125I−I in the presence of chloramine‐T. Purification of 4‐[131I]iodoantipyrine was performed by reversed‐phase liquid chromatography and resulted in a 99 ± 1% radiochemically pure product in an overall 90% yield. The use of iodogen for oxidation of the radioiodine was also investigated.
Preparation of 18O‐bilabelled carboxylic acids: Cinnahic and phenylpropiolic acids via styrylisoxazoles
Authors: Baracchi A , Chimichi S , De Sio F. , Donati D , Nesi R , Sartifantoni P. , Torroba T 
Published: October 2006

Abstract3‐Phenyl‐2‐propenoic (cinnamic) and 3‐ [2H5] ‐phenyl‐2‐ propenoic 80O‐bilabelled acids (2c,d) are prepared via alkaline hydrolysis of styrylisoxazoles (1a,b). The same reaction carried out on the vic‐dibromocompounds (3a,b) gave the 3‐phenyl‐2‐propynoic (phenylpropiolic) and 3‐[2H5]‐Phenyl‐2‐propynoic 18O‐bilabelled acids (4c,d), respectively.
Synthesis of tritiated functionalized congeners of 1.3‐dipropylxanthine having high affinity at adenosine receptors
Authors: Jacobson Kenneth A. , Ukena Dieter , Daly John W. , Kirk Kenneth L. 
Published: October 2006

AbstractTwo potent ligands for adenosine receptors have been synthesized with non‐exchangeable 3H labeling to high specific activity. Both are adenosine antagonists. one a carboxylic acid congener, 1, and the other an amino congener. 2. and are structurally related to 1,3‐dipropyl‐8‐phenylxanthine. The label was introduced at four positions in the n‐propyl groups through catalytic reduction of 1,3‐diallyl precursors. Due to favorable aqueous solubility. high potency and selectivity. these ligands are expected to be suitable for competitive binding assays and autoradiography.
Preparation of (10R,s‐[10‐3H]juvenile hormone III and (10R,S,11S,R)‐[10‐3H]juvenile hormone 0; conversion of [10‐3H] juvenile hormone III to methyl (2E,6E)[10‐3H]Farnesoate and (2E 6E)‐ [10‐3H] farnesol
Authors: Baker Fred. C. , Schooley David A. 
Published: October 2006

AbstractSamples of racemic [10‐3H]juvenile hormone III (methyl (2E,6E)‐10,11‐epoxy‐ 3,7,11‐trimethyl‐2,6‐dodecadienoate) and [10‐3H]juvenile hormone 0 (methyl (2E,6E,10cis)‐3,7‐diethyl‐10,11‐epoxy‐11‐methyl‐2,6‐tridecadienoate) were prepared by NaB3H4 reduction of the corresponding 11‐chloro‐10‐oxo ( “chloroketone” ) precursors to their respective [10‐3H]chlorohydrins, followed by treatment of the latter with potassium carbonate in methanol. [10‐3H]Juvenile hormone III was converted to methyl [10‐3H]farnesoate (methyl (2E,6E)‐3,7,11‐trimethyl‐ 2,6,10‐dodecatrienoate) by reduction with sodium iodide and zinc in acetic acid‐sodium acetate. Further reduction of methyl [10‐3H]farnesoate with diisobutyl aluminum hydride afforded a sample of [10‐3H]farnesol ((2E,6E)‐3,7,11‐trimethyl‐2,6,10‐dodecatrien‐1‐ol).
Preparation of N.C.A. [18F]‐CH2BrF via aminopolyether supported nucleophilic substitution
Authors: Coenen Heinrich Hubert , Colosimo Marcello , Schüller Manfred , Stöcklin Gerhard 
Published: October 2006

AbstractA complex of the macrocyclic aminopolyether Kryptofix® 2.2.2. and potassium carbonate was used to synthesize [18F]‐CH2BrF from dibromomethane. At the no‐carrier‐added level the nucleophilic 18F‐for‐Br exchange gives rise to a corrected radiochemical yield up to 62%.
Synthesis of 14C‐labelled leukotriene receptor antagonists: 5‐Substituted‐4,6‐dithianonanedioic acid derivatives
Authors: Kuot George Y. , Dewey Richard H. , Newton John F. , Perchonock Carl D. , McCarthy Mary E. 
Published: October 2006

AbstractTwo 14C‐labelled leukotriene receptor antagonists were prepared from two aryl bromides and potassium [14C]cyanide. Potassium cyanide was converted to copper(I) [14C]cyanide and was subsequently used to displace the bromine atom from two aryl bromides, 2‐dodecylbromobenzene and 2‐(8‐phenyloctyl)bromobenzene. The resulting nitriles were reduced to aldehydes with diisobutylaluminum hydride and the aldehydes were reacted with 3‐mercaptopropionic acid to give 5‐(2‐dodecylphenyl)‐4,6‐dithianonanedioic acid (14C‐SK&F 102081) and 5‐[2‐(8‐phenyloctyl)phenyl]‐4,6‐dithianonanedioic acid (14C‐SK&F 102922), respectively. These products were snythesized in about 30% overall yield with radiochemical purity of greater than 95%. Their structures were assigned based on the analytical data of the corresponding nonradiolabelled compounds obtained from the nonradioactive preparations.
Synthesis and biodistribution of radioiodinated nicotine analogs
Authors: Chan S. M. , Basmadjian G. P. , Sadek S. A. , Magarian R. A. , Grunder J. R. , Marten D. F. 
Published: October 2006

AbstractFour 125I‐labelled nicotine analogs were synthesized: 3‐(methylpropylaminomethyl)‐, 3‐(diethylaminomethyl)‐, 3‐(isopropylaminomethyl)‐, and 3‐(diisopropylaminomethyl)‐5‐[125I]‐iodopyridines. 5‐Bromonicotinic acid was acylated with thionyl chloride and then reacted with the appropriate primary and secondary amines to give the corresponding amides which were reduced with diborane to the desirable amines. Radioiodination was done by halogen exchange. Biodistribution studies in rats, showed that all four labelled compounds were rapidly taken up by the brain and the adrenal gland. This was followed by rapid washout of the compounds from these orrans. The most promising of these compounds, 3‐(diisopropylaminomethyl)‐5‐[125I]‐iodopyridine, showed a brain‐to‐blood ratio of 6.0:1 and an adrenal‐to‐blood ratio of 35.9:1 at 2 minutes post administration. In vitro correlation studies showed that brain uptake of these compounds depends on both protein binding and lipophilicity, whereas adrenal uptake depends only on lipophilicity.
Synthesis of 2,6‐dimethyl‐l,2,3,4‐tetrahydronaphthalene‐4‐13C and 2,6‐dimethylnaphthalene‐413C
Authors: Bymaster D. L. , Pickering R. E. , Dobbs T. K. , Eisenbraun E. J. 
Published: October 2006

AbstractThe synthesis of specifically labeled β,4‐dimethyl‐benz‐enebutanoic acid‐1‐13C, 3,4‐dimethyl‐ 1,2,3,4‐tetrahydronaphthalene‐4‐13C and 2,6‐dimethylnaphthalene‐4‐13C from Diethyl 2‐(4‐methylphenyl)‐2‐methylpropanediate is described.
Synthesis of deuterium labelled thioridazine
Authors: Mohammad T. , Midha K. K. , Hawes E. M. 
Published: October 2006

AbstractA seven step synthetic route to (±)‐10‐[2‐(1‐methyl‐2‐piperidinyl)ethyl]‐2‐methylthio‐10H‐phenothiazine (thioridazine) was developed starting from racemic ethyl 1‐methyl‐2‐piperidinecarboxylate. The lithium aluminum deuteride reduction of the starting and homologous esters allowed the incorporation of deuterium in the 1‐and/or 2‐position(s) of the ethyl side chain of thioridazine. The isotopic purity of the tetradeuterated and two dideuterated products was greater than 99%.
Syntheses of |6‐2h|‐indole, |6‐2h|‐gramine and |6‐3h|‐gramine
Authors: Ghini A. A. , Burton G. , Gros E. G. 
Published: October 2006

AbstractThe title compounds were obtained from the corresponding 6‐bromo derivatives by conversion to the 1,6‐dilithio‐compounds followed by treatment with deuteriated or tritiated water and exchange of the 1‐deuterium or tritium with water.
Synthesis of 7‐[α‐(2‐aminothiazol‐4‐yl)‐α‐(z)‐methoximinoacetamido]‐3‐(1‐[14C]methylpyrrolidinio)‐methyl‐3‐cephem‐4‐carboxylate sulfate
Authors: Swigor J. E. , Pittman K. K. 
Published: October 2006

AbstractThe synthesis of the title compound (6) is described. The reaction of sodium [14C] formate with acetyl chloride produced the mixed anhydride. Treatment with pyrrolidine gave the N‐formyl compound in a 4 to 1 ratio with the N‐acetyl compound.1 Separation and reduction with lithium aluminum hydride gave N‐[14C]methylpyrrolidine2. Reaction with 7‐[α‐(2‐triphenylmethylaminothiazol‐4‐yl)‐α‐(z)‐methoximinoacetamido]‐1‐oxo‐3‐iodomethyl‐3‐cephem‐4‐carboxylate diphenylmethyl ester introduced the label into the cephalosporin. Treatment with acetyl chloride converted the sulfoxide to the sulfide. Formic acid at 39°C removed the protecting groups and treatment with 4N sulfuric acid produced the title compound as a sulfate salt.
Synthesis of 1‐[14C]methyl‐1H‐tetrazole‐5‐thiol([14C]NMTT) and [NMTT‐[14C]]latamoxef
Authors: Nagasaki T. , Katsuyama Y. , Yoshioka M. 
Published: October 2006

AbstractThe title compounds were prepared for metabolic studies, with the 14C labelling being made at methyl of the 1‐methyl‐1H‐tetrazol‐5‐ylthio (NMTT) group in overall radiochemical yields of 26% and 22% based on barium [14C]carbonate, respectively.
Preparation of 2H‐ and 13C‐labelled precursors of 2‐hydroxy‐1,3‐butadiene
Authors: Tureček František 
Published: October 2006

Abstract2‐exo‐Vinylbicyclo[2.2.1]hept‐5‐en‐2‐ols, specifically labeled with 2H at C‐3 and in the vinyl group were prepared from bicyclo [2.2.1]hept‐5‐en‐2‐one in several steps. [4‐13C]Oct‐1‐en‐3‐one was prepared in five steps from 13CO2. These compounds serve as precursors for the preparation of specifically labeled neutral and ionized 2‐hydroxy‐1,3‐butadienes.
Synthesis of carbon‐14 labeled 4‐bromo‐2,7‐dimethoxy‐3H‐phenothiazin‐3‐one
Authors: Prakash S. R. , Ellsworth R. L. , Mertel H. E. 
Published: October 2006

AbstractTwo different syntheses of (5), one labeled with carbon‐14 in the quinonoid ring and the other in the phenyl ring are described. Treatment of p‐[U‐14C]benzoquinone with 2‐amino‐5‐methoxy benzenethiol yielded (7), which was methoxylated to provide a mixture of isomers (4a) and (8). Separation of isomers followed by bromination of (4a) gave (5a). Thiocyanation of p‐[U‐14C]anisidine provided (10), which was hydrolysed to give labeled aminothiol (3b); the latter was condensed with 2‐bromo‐6‐methoxy‐p‐benzoquinone to afford (5b).
Synthesis of 14C‐labelled 2‐aminopyridine
Authors: Lenoir H. H. C. , Janssen C. C. M. 
Published: October 2006

Abstract2‐Aminopyridine is a versatile building block in the preparation of certain heterocycles such as imidazo[1,2‐a]‐pyridines, pyrido[1,2‐a]‐pyrimidin‐ones and substituted derivatives there‐of. 14C‐labelled 2‐aminopyridine was synthesized as follows: potassium‐[14C]cyanide (I) was reacted with epichlorohydrin (II) to give 3‐hydroxy‐[1,5‐14C2]pyridine (IV) which was then reductively dehalogenated to the 2,6‐14C2‐labelled title compound (V) in 36 % overall chemical and radio‐chemical yield, based upon I. The product was radiochemically pure (99.1 %) according to high‐performance liquid chromatography and thin‐layer chromatography, and had a specific activity of 9.06 mCi/mmol.
Synthesis of 4‐[2‐(DI‐n‐propylamino)ethyl]‐[2‐14C]‐2(3H)‐indolone
Authors: Heys J. Richard 
Published: October 2006

Abstract4‐[2‐(Di‐n‐propylamino)ethyl]‐2(3H)‐indolone (1) labeled with 14C at C2 was prepared by a simple and efficient procedure involving carbonation of a stabilized benzyllithium species, followed by ring closure under hydrolytic conditions.
Microscale synthesis of high specific activity 3H‐nitroglycerin
Authors: Kawamoto J. J. , Brien J. J. , Marks G. G. , Nakatsu K. 
Published: October 2006

AbstractThe synthesis and purification of 3H‐nitroglycerin (glyceryl trinitrate, GTN) from commercially available 3H‐glycerol of high specific activity are described. The optimum microscale reaction conditions were defined. Purification of the product by thin‐layer chromatography produced 3H‐GTN with an overall molar yield of 65% and a radiochemical purity of 99.0%.
Crown ether catalyzed deuterium exchange in the synthesis of benzyl cyanides
Authors: Davis Bruce 
Published: October 2006

AbstractNucleophilic substitution of benzyl‐type chlorides with cyanide ion in deuterochloroform, deuteroacetonitrile or deuterobenzene catalyzed by 18‐crown‐6 results in the introduction of deuterium onto the benzyl carbon. Benzyl cyanides are labelled by refluxing with cyanide ion and crown ether in deutero solvent. Two such exchanges in deuterochloroform produced greater than 90% incorporation. Side‐chain labelled phenyl‐ethylamine, tryptamine and m‐ and p‐tyramine were synthesized in this way.
Synthesis of 11C‐pindolol
Authors: Prenant C. , Sastre J. , Crouzel C. , Syrota A. 
Published: October 2006

AbstractA method is described by which 100 mCi of pindolol may be obtained from about 1.5 Ci 11CO2 in 30 minutes. The product is chromatographically pure, sterile and apyrogenic with a specific activity between 600 and 1000 mCi/μmole at the time of use.The synthesis involves the preparation of 11C‐acetone followed by fixation of the isopropyl group on the precursor : 2 hydroxy‐3 (4‐indolyoxy) propylamine by formation of an imine, the reduction of the latter by sodium cyanoborohydride.
Synthesis of S‐benzyl‐[18O3]phosphorothioate and adenosine 5prime;‐[18O3]phosphate
Authors: Bethell Richard C. , Lowe Gordon 
Published: October 2006

AbstractSeveral synthetic routes to the two title compounds are presented. S‐Benzyl‐[18O3]phosphorothioate was synthesised in 68% yield from phosphorus trichloride. Adenosine 5′‐[18O3]phosphate was synthesised in two steps from adenosine in 44% yield.
Synthese des Isomeres (E) et (Z) de la Phenylhydrazone De L'hexanal (noyau 14C ‐ U)
Authors: Do‐Cao‐Thang  , Nguyen‐Hoang‐Nam  , Chopard C. , Galey J. B. , Chottard J. C. 
Published: October 2006

AbstractSynthesis and chromatographic separation of (E) and (Z) isomers of (ring‐U‐14C) hexanal phenylhydrazone 2 : (ring‐U‐14C) phenylhydrazine hydrochloride 1 was synthesized from labelled aniline hydrochloride, and purification was accomplished by reverse phase low pressure liquid chromatrography. The crude free base of 1 was condensed with hexanal to give a mixture of (E) and (Z) isomers of 2. The conditions for their separation by reverse phase HPLC were optimized on an analytical column and then used for the preparative work which was the most effective and fastest method.Structure and configuration of (E) and (Z) isomers of (ring‐U‐14C) hexanal phenylhydrazone (SA = 13.3 mCi/mmol) were proven by 1H‐NMR and mass spectroscopy.
A simple procedure for the preparation of tritiated homovanillic acid
Authors: Keenan Roy W. 
Published: October 2006

AbstractHomovanillic acid (4‐hydroxy‐3‐methoxyphenylacetic acid) was labeled with tritium by exchange reaction in tritiated water catalyzed by sulfuric acid. The product was obtained in good yield and specific activities sufficient be utilized in metabolic experiments. Reactions carried out under identical conditions, but in the presence of deuterated water gave a product in which all the aromatic hydrogens and those α ‐ to the carboxyl group were replaced with deuterium indicating that the tritium‐labeled homovanillic acid was labeled in these positions.
Oxidation of cystine to cysteic acid by bromine in 18O‐labelled water, evidence for a cyclic carboxylic‐sulfenic anhydride
Authors: White Robert H. 
Published: October 2006

AbstractOxidation by bromine of L‐cystine dissolved in acidified 18O‐enriched water (95 atom % 18O) led to the production of cysteic acid which contained two 18O atoms in the carboxylic acid protion and two 18O atoms in the sulfonic acid portion of the molecule. It is postulated that the incorporation of a single 16O into the sulfonic acid results from an intramolecular transfer of a carboxyl oxygen via a cyclic carboxylic‐sulfenic anhydride intermediate which is formed during the oxidation. The remaining carboxyl oxygen is postulated to exchange from either the cyclic anhydride or the free carboxylic acid during the reaction.
Synthesis of U‐14C‐labelled 5‐hydroxymethyl‐2‐furaldehyde
Authors: Germond J. J. , Arnaud M. M. 
Published: October 2006

AbstractUniformally 14C‐labelled 5‐hydroxymethyl‐2‐furaldehyde was synthesized by dehydration of D‐[U‐14C]fructose on an H+ ion exchange resin and a water isobutylmethyl ketone biphasic liquid reaction medium. The optimal reaction time was 45min, and after HPLC purification the radiochemical yield was 50%. The whole process took 2 hours.
Synthesis of carbon‐14 labeled CI‐926 and CI‐927, new antihypertensives
Authors: Hays Sheryl J. 
Published: October 2006

Abstract3‐[4‐]4‐(3‐Methylphenyl)‐1‐piperazinyl[butyl]‐2,4‐imidazolinedione, CI‐926 (1), and 3‐[4‐4‐(3‐ethoxyphenyl)‐1‐piperazinyl]butylamino‐5,5‐dimethyl‐2‐cyclohexen‐1‐one, CI‐927 (2) are new antihypertensive agents which have been carbon‐14 labeled in three steps starting from ethylene‐14C2 oxide (5). The overall radiochemical yields for 1 and 2 were 69% and 66% respectively. The specific activity for both compounds was initially 22.6 mCi/mmol before final dilution.
Synthesis of tritium labeled O‐ethyl‐D‐tyrosine and phenylalanine
Authors: Landvatter Scott W. , Heys J. Richard , Senderoff Stephen G. 
Published: October 2006

AbstractTwo amino acids, t‐BOC‐O‐ethyl‐D‐tyrosine and t‐BOC‐phenylalanine, have been synthesized in tritium labeled form via exchange with tritium gas over catalyst on an unlabeled precursor and dehydrohalogenation on an iodinated precursor respectively. The tyrosine derivative has been obtained in specific activities of 4 ‐ 7 Ci/mmol; tritium NMR indicates that at least 80% of the tritium resides in the benzylic position of the molecule. The phenylalanine has been synthesized with a specific activity of greater than 35 Ci/mmol. Tritium NMR confirms specific tritium/iodine replacement in the position.