bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of osseous specific 32P‐labeled disodium ethane‐1‐hydroxy‐1,1‐diphosphonate
Authors: McCreary Lionel D. , Tofe Andrew J. , Francis Marion D. 
Published: October 2006

AbstractHigh specifie activity 32P‐Iabeled disodium ethane‐1‐hydroxy‐1,1‐diphosphonate has been prepared for specific use as a radiotherapeutic ameliorative treatment of osseous tumors by reacting 32P‐labeled phosphorus trichloride, acetic acid and water. This compound has been purified by crystallization of the disodium salt from a water‐ethanol solution. Product identity and purity were established by reverse isotope dilution analysis. Spectrochemical quantitation, thin layer chromatography, radionuclide beta energy and half‐life determinations are presented as essential procedures for establishing chemical and radiochemical purity when human distribution studies are planned.
Tritium and deuterium exchange‐labeling of aromatic and organometallic compounds in heptafluorobutyric acid
Authors: Hanzlik Robert P. , Wiley Robert A. , Gillesse Timothy J. 
Published: October 2006

AbstractThe use of heptafluorobutyric acid (HFBA) as a solvent/reagent for tritiation (or deuteration) or aromatic organic and organometallic compounds is described. Typically the substrate (0.1–1 mmole) and tritium oxide (5–25 μl, 5 Ci/g) are dissolved in 0.3–1 ml HFBA and heated at 130–145° for 4–7 days. Aromatic compounds bearing electron‐donating substituents are tritiated much more readily than those bearing electron withdrawing substituents. Substrate decomposition was minimal, and good to excellent yields of relatively pure tritiated materials are obtained simply by cooling, neutralization, and extraction. Detailed studies of deuterium exchange in HFBA‐d under analogous conditions are also reported.
Synthesis of some unsymmetrically deuterated cyclohexanols
Authors: Stibbe W. , Schrumpf G. 
Published: October 2006

AbstractThe preparations of [1,2,2,3,3,6,6‐D7]Cyclohexanol, and of two isotopameric [1,2,2,3,4,5,5,6,6‐D9]Cyclohexanols are described. The isotopic purity of the deuterium labeled cyclohexanols is better than 90 %.
Determination of tritium or deuterium in the methyl group of labeled organic compounds
Authors: Valentekovic D. , Hirwe N. S. , Nystrom R. F. 
Published: October 2006

AbstractThe determination of the isotopic content of C‐methyl groups in selected tritium and deuterium labeled compounds by modification of the Kuhn‐Roth method is presented. Oxidation of the deuterated or tritiated compound using a solution of sodium dichromate and sulfuric acid at 50–85°C allows isotopic assay of the C‐methyl group as acetic acid.
An efficient and convenient synthesis of 5‐(3,3‐dimethyl‐14C‐1‐triazeno)‐imidazole‐4‐carboxamide
Authors: Farquhar D. , Benvenuto J. A. , Loo Ti Li 
Published: October 2006

AbstractReaction of dimethylamine‐14C with a four‐fold molar excess of 5‐doazoimidazole‐4‐carboxamide in methanol followed by column chromatography of the product on basic alumina afforded 5‐(3,3‐dimethyl‐14C‐1‐triazeno)imidazole‐4‐carboxamide in 70–75% yield and greater than 99.9% radiochemical purity. The preparation is suitable for chemical and biological mechanistic studies.
An improved method of preparation of potassium cyanide‐14C
Authors: Perry Clark W. , Burger Walter , Delaney Charles M. 
Published: October 2006

AbstractA safe procedure for the conversion of barium carbonate‐14C to potassium cyanide‐14C on a 6–7 mmol scale in 90–98% yield was developed. Barium carbonate 14C was heated with excess potassium azide in a matrix of sand without added potassium metal, allowing safe, rapid and convenient recovery of the cyanide.
Syntheses de Phenyl‐2 Oxetannes marques au Deuterium et AU13C
Authors: Schaal C. , Ricard M. 
Published: October 2006

AbstractFive mono, di, tri and pentadeuterated 2‐ phenyloxetanes were prepared either by tosylation and cyclisation of the corresponding 2‐phenyl propanediol (mono, di, tri, pentadeuterated) or from the benzoyl ethylacetate by exchange under acid conditions. The 2‐phenyloxetane 13C was synthesized from benzaldehyde 13C.
The synthesis of deuterium labelled analogues of a novel antidiarrhoeal agent, 2‐[ 3,3‐diphenyl‐3‐(2‐methyl‐1,3,4‐oxadiazol‐5‐yl) propyl] ‐2‐azabicyclo[2,2,2] octane
Authors: Buckley P. H. , Dickens J. P. , Harrow T. A. , Honeyman R. 
Published: October 2006

AbstractThe synthesis of three deuterated analogues[d4, d6 and d9] of the novel antidiarrhoeal agent 2‐[3,3‐diphenyl‐3‐2‐methyl‐1,3,4‐oxadiazol‐5‐yl) propyl]‐2‐azabicyclo[2,2,2]octane is described. The compounds prepared were of high isotopic purity and were used in metabolism and bioavailability studies.
The preparation of Nτ‐ [3H]methylhistamlne dihydrochloride and Nτ‐methyl[α,β,2,4,5‐14c5]histamlne dihydrochloride
Authors: Knight R. I. , Morecombe D. J. , Saunders D. , Smith I. R. 
Published: October 2006

AbstractIn order to study some aspects of the central metabolism of histamine we have prepared Nτ‐ [3H]methylhistamine dihydrochloride from [3H]methyl iodide by chemical synthesis and Nτ‐methy[α,β,2,4,5‐14C5]histamine dihydrochloride from [α,β,2,4,5‐14C5]histamine dihydrochloride by an enzymatic method.
Syntheses with stable isotopes: DL‐valine‐13C3
Authors: Whaley T. W. , Kerr V. N. , Lyle T. A. , Daub G. H. , Olsont E. S. 
Published: October 2006

AbstractThe synthesis of DL‐2‐amino‐3‐methyl‐13C‐butanoic‐3,4‐13C3 acid (DL‐valine‐13C3) is described. Acetonitrile‐2‐13C was converted to 2‐methyl‐13C‐2‐thiazoline, which was dialkylated with methyl‐13C iodide to give 2‐(isopropyl‐13C3)‐2‐thiazoline. Subsequent reduction and hydrolysis of the isopropylthiazoline afforded 2‐methyl‐13C‐propanal‐2,3‐13C2, which was isolated as the bisulfite addition product. A modified Strecker synthesis with the bisulfite compound gave DL‐valine‐13C3 in good overall yield.
Marquage par le 14C du Chlorhydrate de Diphenyl Acetate de NN Diethyl Amino‐2 Ethyle ou Adiphenine
Authors: Madelmont Jean‐Claude , Michelot Josette 
Published: October 2006

AbstractL 'adiphénine a été marquéé en deux positions par 14C ‐ sur la partie éthanol amine par l'intermédiaire d'éthanolamine 14C ‐ sur le groupe carboxyle à l'aide de dioxyde de carbone 14C.
Tritium labelling of morpholine on gamma‐irradiated silica gel
Authors: Crossley P. C. , Hannan S. F. , Odell A. L. 
Published: October 2006

AbstractThe use of gamma‐irradiated silica gel to promote exchange between tritium gas and carbon‐bound hydrogen has been previously described.(1,2,3) The suitability of this method for labelling molecules containing labile as well as carbon‐bound hydrogen has not hitherto been reported.The labelling of morpholine to facilitate its use as a weak base indicator as part of a study of intracellular pH(4) afforded an opportunity to test the suitability of gamma‐irradiated silica gel as a labelling reagent.
Synthesis of (1‐14C)valine
Authors: Meesschaert B. , Adriaens P. , Eyssen H. 
Published: October 2006

AbstractThe method for the synthesis of DL‐(1‐14C)valine (reaction of ethyl N‐(1‐phthalimido)‐isobutyl‐1‐carbamate with K14CN in ethyl alcohol, followed by acidic hydrolysis of the labelled nitrile) reported by Egyed et al. (Acta Chim. Hung. 38: 123, 1963) was studied. The yield of valine could be increased to 75‐80 % by using dry isopropyl alcohol and extending the hydrolysis with hydrochloric acid‐acetic acid to 36 hours. This is better than or comparable to the yields obtained with the Strecker or Bucherer methods. Since the replacement of the phthalimido ring with cyanide proved to be of the SN1 type, a stereospecific synthesis of L‐ or D‐(1‐14C)valine was not possible.
Synthesis of 21‐[82Br]‐21‐deoxyuridine
Authors: Lee Y. W. , Knaus E. E. , Wiebe L. I. 
Published: October 2006

AbstractReaction of 2,21‐anhydrouridine (2) with [82Br]‐ammonium bromide in the presence of one equivalent p‐toluenesulfonic acid afforded 21‐[82Br]‐21‐deoxyuridine (3) in 73.4% chemical yield with a specific activity of 0.58 mCi mM−1. Alternatively, direct activation of 21‐bromo‐21‐deoxyuridine at a thermal neutron flux of 1 × 1012n cm−2s−1 gave 21‐[82Br]‐21‐deoxyuridine, with a specific activity of 0.6‐0.7 mCi mM−1 for a 3 hr irradiation. 21‐[82Br]‐21‐deoxyuridine was rapidly purified by high pressure liquid chromatography with an elution time of 18 minutes, or by preparative thin layer chromatography.
Preparation of carbon‐14 labelled mecarbam (O,O‐DI‐[1‐14c]‐ethyl s‐[N‐ethoxycarbonyl‐N‐methylcarbamoylmethyl] phosphorothiolothionate)
Authors: Hudson H. R. , Pianka M. , Powroznik L. , Lynch V. P. 
Published: October 2006

AbstractO,O‐Vi‐ [1‐14C]‐ethyl S‐ [N‐ethoxycarbonyl‐N‐methylcarbamoylmethyl] phosphorothiolothionate has been prepared with a specific activity of 1.97 mCi mmol−1. The procedure involved the interaction of [1‐14C]‐ethanol with phosphorus pentasulphide in benzene, followed by conversion of the so‐formed diethyl dithiophosphoric acid to its potassium salt and reaction of this with ethyl N‐chloroacetyl‐N‐methylcarbamate in acetone. G.l.c. analysis of the final product in benzene solution showed the purity to be not less than 97 %.
A convenient method for the specific tritium labelling of beta‐adrenoceptor antagonists
Authors: Arfwidsson Anders , Hallhagen Göran , Hoffmann Kurt‐Jürgen 
Published: October 2006

AbstractThe specific tritium labelling of beta‐adrenoceptor antagonists of the general structure ArOCH2CH(OH)CH2NHR is described. The tritium label is introduced in the 2‐position in the aminohydroxypropoxy side‐chain starting from ArOCH, an intermediate in the synthesis of the unlabelled compound. The key step is a reduction of the corresponding bromoketone ArOCH2COCH2Br using readily available sodium borohydride‐3H as the labelling reagent. The 2‐position has proven stable enough to be suitable for most biochemical applications, e.g. metabolic studies. Five examples are given, including alprenolol‐3H and metoprolol‐3H.
Synthesis of 5′, 5′‐Dideuterated nucleoside and nucleotide anabolites of 6‐Mercaptopurine
Authors: Jardine Ian , Weidner Mark M. 
Published: October 2006

Abstract6‐Mercaptopurine riboside, 6‐methylmercaptopurine riboside, 6‐mercaptopurine riboside‐5′‐phosphate and 6‐methylmercaptopurine riboside‐5′‐phosphate were synthesized with 2 deuteriums in the ribose moiety at the 5′‐position so as to act as internal standards for the quantitation of these anabolites of 6‐mercaptopurine from biological media by gas chromatography‐selected ion monitoring mass spectrometry with chemical ionization.
Resolution of tritium‐labelled amino acid racemates by ligand‐exchange chromatography. Part 1. Method for obtaining L‐ and D‐[3H]valine using a polystyrene resin with L‐hydroxyproline groupings
Authors: N. F. Myasoedov , O. B. Kuznetsova , O. V. Petrenik , V. A. Davankov , Yu. A. Zolotarev 
Published: October 2006

AbstractLigand‐exchange chromatography is shown to be applicable for obtaining the optical isomers of [3H]valine. Data are presented showing the effect of the asymmetric sorbent's structure on its kinetic properties and the optimum conditions selected for the chromatographic resolution of D, L‐[3H] valine. The method makes it possible to obtain both isomers of [3H]valine with an optical purity close to 100% in about 2 hours with a simultaneous radiochemical purification. The method does not require any preliminary chemical modification of the amino acid and does not impose any limitations to specific activity values.
Tritium labelling and tritium N.M.R. ‐ part I alpha‐labelled stearic, palmitic, myristic and lauric acids
Authors: Crossley P. C. , Martin R. W. , Mawson J. B. , Odell A. L. 
Published: October 2006

AbstractStearic, palmitic, myristic and lauric acids have been labelled with tritium in the alpha carbon position, and the position of the label confirmed using tritium N.M.R. spectrometry. The α‐3H acids were prepared using tritiated water with sulphuric acid or sodium hydroxide as catalysts. Specifically labelled compounds of high specific activity and radiochemical purity were obtained.
Synthesis of deuterium‐labelled N,N‐dimethyl‐morpholinium‐ and N‐methyl‐N‐ethyl‐morpholinium‐ 7,7,8,8‐tetracyanoquinodimethane complexes
Authors: Kwant B. H. 
Published: October 2006

AbstractAttempted exchange experiments of morpholine, N‐methylmorpholine and N‐ethylmorpholine with a deuterium donor led to no deuterium incorporation in the morpholine rings. Morpholine‐d8 is not found in the reaction of bromoethanol‐d5 and ammonia, but it can be prepared from ethyleneoxide‐d4 and ammonia. These reaction conditions are given for the H‐analog. N‐methylmorpholine‐d11 is prepared from ethyleneoxide‐d4 and methylamine‐d5 N‐ethylmorpho‐Line‐d13 is prepared in an analogous manner. N‐methyl‐d3‐morpholine is prepared from morpholine and diazomethane‐d2 or from morpholine and methyliodide‐d3 or from 2,2′‐bis‐(iodoethyr)ether and methyllamine‐d5 N‐methyl‐N‐ethyl‐d5‐morpholinium(M.E.M.‐d5)‐iodide is preparea from N‐methylmorpholine and ethyliodide‐d5 M.E.M.‐d16‐iodide and M.E.M.‐iodide are obtained by a similar route. N,N‐di‐(methyl‐d3)‐morpholiniumiodide is prepared from N‐methyl‐d3Morholine and methyliodide‐d3 and also from morpholine and methyliodide‐d3 M.E.M.‐(T.C.N.Q.‐d4)2; M.E.M.‐d5‐(T.C.N.Q.‐d4)2; M.E.M. d16‐(T.C.N.Q.‐d3)2; M.E.M.‐d16‐(T.C.N.Q.)2; and N,N‐di‐(methyl‐d3)‐ morpholinium‐(T.C.N.Q.)2 are prepared from the deuterated or undeuterated morpholiniumiodides and T.C.N.Q. All synthetic methods are described in detail.
Synthese De L'Acide Dimercapto‐2,3 Succinique‐14C‐2,3
Authors: Compagnon P.‐L. , Kimny Tan , Rapin J. R. 
Published: October 2006

AbstractThe synthesis of 14C‐2,3 dimercapto sucinic acid (DMSA) is described. The starting material 14C‐2,3 succinic acid was brominated and then deshydrohalogenated to give acetylenedicarboxylic acid. This 14C‐acetylenic compound was transformed into 14C‐dithioacetylsuccinic acid. This latter compound was hydrolysed with sodium hydroxyde to give 14C‐DMSA. The overall yield was 57% at a specific activity of 1.6 mCi/mM.
A simple and efficient synthesis of [3H]cholesteryl 14‐methylhexadecanoate
Authors: Helmich O. , Hradec J. 
Published: October 2006

AbstractThe reaction of labelled cholesterol with a large excess of freshly prepared 14‐methylhexadecanoyl chloride in a simple glass apparatus was used for the synthesis of [3H]cholesteryl 14‐methylhexadecanoate in microgram amounts. After purification of the crude product by thin‐layer chromatography, the purity of the final preparation was better than 98% as checked by gas‐liquid and high‐pressure liquid chromatography. On average 90% of the input radioactivity was present in the ester. The same technique was also used for the preparation of [14C]cholesteryl 14‐methylhexadecanoate and [3H] or [14C]cholesteryl laurate, myristate, palmitate, margarate and stearate with similar yields. All these preparations were found suitable for biochemical studies.
Convenient methods for the preparation of [5‐14C]‐4‐ipomeanol and [3H(G)]‐4‐ipomeanol of high specific radioactivity
Authors: Boyd Michael R. , Dutcher John S. 
Published: October 2006

AbstractProcedures are described for the preparation of radiolabeled 4‐ipomeanol [1‐(3‐furyl)‐4‐hydroxypentanone], a highly selective pulmonary alkylating agent, of sufficiently high specific radioactivity for biochemical and autoradiographic studies. The 14C‐labeled material is prepared from the reaction of ethyl 3‐fur‐oylacetate with [3‐14C]‐propylene oxide; the tritiated product is obtained by catalytic tritiation using T2O or tritium gas as the source of the radiolabel.
Synthesis of microamounts of ketones from carboxylic acids: 1‐phenoxy‐2‐butanones‐2‐14‐14C
Authors: Look Melvin 
Published: October 2006

AbstractA technique using acetic acid as a co‐reactant for synthesizing microamounts of radiolabelled ketones from carboxylic acids with ethyl lithium is described. The acetic acid forms methyl ethyl ketone, a compound easily separated from the radiolabelled products.
Synthesis of tritium labelled 4‐fluoro‐1‐[1–(2‐thienyl)]cyclohexylpiperidine ([3H]‐FTCP); a tool for autoradiographic study of the phencyclidine binding site
Authors: Thurkauf Andrew , De Costa Brian R. , Kiesewetter Dale O. , Jacobson Arthur E. , Rice Kenner C. 
Published: October 2006

Abstract4‐Fluoro‐1–[1–(2‐thienyl)‐3‐cyclohexenyl)] piperidine was efficiently synthesized in four steps starting from cyclohexane‐1, 4‐dione monoethylene ketal. Catalytic tritiation of this key intermediate in the final step afforded the title compound.
Optimized synthesis of radioiodinated rhodamine‐123
Authors: Vora Manhar M. , Lambrecht Richard M. 
Published: October 2006

AbstractRhodamine‐123 (Rh123) was iodinated with 123I in presence of Iodogen. Yield of the labelled Rh123 varied greatly depending upon various reaction parameters. Optimum reaction conditions with respect to molarity and pH of the buffer, reaction time, amounts of iodogen, carrier iodide and Rh123, were determined through carefully controlled reactions. Radiochemical yields of 50–60% were obtained within less than 2 hrs. using 0.05M NH4H2PO4 buffer at pH5, 200 μg iodogen, 250 μg Rh123 and no‐carrier‐added iodide. Separation of the labelled Rh123 in greater than 98% radiochemical purity was achieved by flash chromatography on silica gel. The overall isolated yield of radioiodinated Rh123 ranged from 25–35% with respect to the added radioiodide. TLC and HPLC methods were developed for analysis of the labelled products.
Synthesis of a cleavable heterobifunctional photolabelling reagent: Ring‐labelled 3‐[(4‐azidophenyl)dithio]propionic acid‐14C
Authors: Ramaswami Varadarajan , Tirrell David A. 
Published: October 2006

AbstractAn efficient synthesis of ring‐labelled 3‐[(4‐azidophenyl)dithio]propionic acid‐14C is described. Chlorosulfonation of uniformly ring‐labelled acetanilide‐14C followed by reductive dimerization of the sulfonyl chloride with HI afforded 4‐acetamidophenyl disulfide. Hydrolysis and diazotization then gave 4‐azidophenyl disulfide, which was converted to the title compound via the sulfur transfer reagent N‐(4‐azidophenylthio)phthalimide. The overall yield of 3‐[(4‐azidophenyl)dithio]propionic acid‐14C was 22%. 3‐[(4‐Azidophenyl)dithio]propionic acid‐14C is a cleavable heterobifunctional photolabelling reagent of potential utility in studies of biomembrane structure and intermacromolecular interaction.
Synthesis of 14C labelled acrylic derivatives: Diethyl [3‐14C] methylidenemalonate and isobutyl [3‐14C] cyanoacrylate
Authors: De Keyser Jean‐Luc , De Cock Christian J. C. , Poupaert Jacques H. , Dumont Pierre 
Published: October 2006

AbstractIsobutyl [3‐14C] cyanoacrylate and diethyl [3‐14C] methylidenemalonate were synthesized by the intermediate of their protective Diels‐Alder adduct with anthracene. These adducts (2a‐b) were obtained in a one‐pot procedure by Knoevenagel condensation of [14C] paraformaldehyde with isobutyl cyanoacetate and diethyl malonate respectively in the presence of a basic catalyst and anthracene. The adducts are stable crystalline compounds easily purified by recrystallization. The olefinic target coumpounds (1a‐b) were obtained in high chemical and radiochemical purity (>99%) by thermolysis at 220 °C in mineral oil in the presence of maleic anhydride.
Synthesis of [17O]‐ and [18O]‐labelled hypophosphate
Authors: Potter Barry V. L. 
Published: October 2006

AbstractThe preparation of 17O‐ and 18O‐labelled hypophosphate by oxidation of diphosphite (P2‐P4 acid) with iodine‐water is described. The 162 MHz NMR 31p(18O) isotope shift of 18O‐labelled hypophosphate is 2.42 Hz (0.0149 ppm), the relatively large value compared to 18O‐pyrophosphate, 1.73 Hz (0.0107 ppm), being suggestive of an as yet unobserved 31P(18O) β‐isotope shift of 1.38 Hz (0.009 ppm)
Use of solvent vapour pressure to evacuate the installation in carbonations of grignard reagents
Authors: Schiketanz Ana , Pogany Iuliu , Gheorghiu Mircea D. , Necula Atena , Balaban Alexandru T. 
Published: October 2006

AbstractAn installation is described for the carbonation of organomagnesium reagents with 13CO2 or 14CO2. The obtained vacuum results by sweeping all permanent gases with solvent vapour (ethyl ether or tetrahydrofuran) at room temperature under moderate vacuum. Specific steps in the carbonation procedure are indicated, leading to good yields of carboxyl‐labelled acids.
Synthesis of 3‐quinuclidinol‐18O, benzilic‐d5 acid, and 3‐quinuclidinyl‐18O benzilate‐d5
Authors: Sniegoski Lorna T. , Byrd Gary D. , White V Edward 
Published: October 2006

AbstractIsotopically labeled analogs of 3‐quinuclidinol (Q), benzilic acid (BA), and 3‐quinuclidinyl benzilate (BZ), for use as internal standards for isotope dilution measurements and the labeled intermediates 3‐quinuclidinone and methyl benzilate used in their production, were synthesized. The isotopic purities of the 1‐azabicyclo[2.2.2]octan‐3‐18O‐ol, α‐hydroxy‐a‐phenyl‐d5‐benzeneacetic acid, and 3‐quinuclidinyl‐18O benzilate‐d5 were determined and the electron impact ionization mass spectrum was obtained for each.
Syntheses of [2‐13C] and [1,2‐13C] labelled α‐ketoglutaric acid
Authors: Baldwin Jack E. , Adlington Robert M. , Russell Mark A. , Schofield Christopher J. , Wood Mark E. 
Published: October 2006

AbstractThe syntheses of α‐keto[2‐13C]glutaric acid and α‐keto[1,2‐13C]glutaric acid were each achieved from commercial 13CH3I in 5 steps. 13CH3NO2, prepared in situ from 13CH3I and AgNO2, was treated with magnesium methyl carbonate, followed by acidified methanol to give O2N13CH2CO2CH3. Michael addition to methyl acrylate, followed by in situ nitronate formation and ozonolysis gave the dimethyl ester of α‐keto [2‐13C]glutaric acid, which was deprotected with hydrochloric acid. O2N13CH213CO2CH3 was prepared from 13CH3NO2 by reaction with aqueous KOH, followed by treatment with acidified methanol, and was converted to 1,2‐13C‐α‐ketoglutaric acid in a similar fashion to that used for mono‐labelled material.
Synthesis of 9‐[(2‐chloro‐6‐fluorophenyl) [14C]methyl]‐9H‐purine‐6‐amine (arprinocid) and 9‐[(2,6‐dichlorophenyl) [14C]methyl]‐9H‐purine‐6‐amine
Authors: Ellsworth Robert L. , Meriwether Henry T. , Mertel Holly E. 
Published: October 2006

AbstractThe synthesis of 9‐[(2‐chloro‐6‐fluorophenyl)methyl]‐9H‐purin‐6‐amine (arprinocid, a coccidiostat candidate) and 9‐[(2,6‐dichlorophenyl)methyl]‐9H‐purin‐6‐amine labeled with carbon‐14 in the benzylic methylene carbon of each of these is described. Introduction of the carbon‐14 label leading to the formation of the key radioactive intermediates, 2‐chloro‐6‐fluoro[carboxyl‐14C]benzoic acid and 2,6‐dichloro‐[carboxyl‐14C]benzoic acid, was accomplished by utilizing [14C]carbon dioxide for carbonation of a suitable dihalo‐phenyl Grignard or organolithium reagent.
Synthesis of 2‐[4‐(diphenylmethyl)‐1‐piperazinyl]ethyl methyl (±)‐1,4‐dihydro‐2,6‐dimethyl‐4‐(m‐nitrophenyl)‐3,5‐[6‐14C]pyridinedicarboxylate dihydrochloride ([14C]CV‐4093 (2HCl))
Authors: Tada Norio , Kajino Masahiro , Watanabe Masazumi , Hayashi Nobuyoshi 
Published: October 2006

AbstractThe carbon‐14 labelled compound (5) of 2‐[4‐(diphenylmethyl)‐1‐piperazinyl]ethyl methyl (±)‐1,4‐dihydro‐2,6‐dimethyl‐4‐(m‐nitrophenyl)‐3,5‐pyridinedicarboxylate dihydrochloride (CV‐4093 (2HCl)) was synthesized for the study of its metabolism and distribution in test animals. Starting from the commercially available ethyl[3‐14C]acetoacetate (1), 5 was prepared by a modified Hantzsch synthesis, in an overall radiochemical yield of 23.7%.
Synthesis and NMR spectra of 17oxygen enriched phenols
Authors: Bank Shelton , Longley Kathryn L. 
Published: October 2006

AbstractAn efficient and convenient method of preparing 17O enriched phenols is described. Aryl boronic acids are oxidized with 17O enriched potassium hydroperoxide. The 17O labeled potassium hydroperoxide is prepared from the autoxidation reaction of benzhydrol with 17O enriched oxygen gas in the presence of potassium t‐butoxide. [0–17]Phenol, p‐bromo[0–17]phenol and p‐methoxy[0–17]phenol were prepared in good to modest overall chemical yields (40–60%) and high isotopic retention (82–90% from 16.8 atom % 17O2 starting material). 17O NMR spectra of the three enriched phenols demonstrate the benefits of using enriched samples in reducing the total experiment time and greatly improving the signal‐to‐noise ratio compared to unenriched samples.