bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of lipoidal drugs: ‐ Glycerides of radiolabelled aspirin
Authors: Kumar R. , Billimoria J. D. 
Published: October 2006

AbstractTriglycerides containing aspirin in place of one or more fatty acid residues have been synthesised. Glycerol, mono and di palmitic acid glycerides were acylated with the acid chloride of [ 14C‐carboxyl ]‐aspirin to give the corresponding tri‐, di and mono‐aspirin glycerides.
Tritium nuclear magnetic resonance spectroscopy part 12. Patterns of labelling in tritiated folic acid and methotrexate
Authors: Evans E. Anthony , Kiteher J. Philip , Warrell David C. , Elvidge John A. , Jones John R. , Lenk Robert 
Published: October 2006

AbstractLabelling patterns in tritiated folic acid and methotrexate have been examined by tritium nuclear magnetic resonance spectrometry. The results indicate that oxidative degradation with permanganate can give a false tritium distribution.
The synthesis of estragole labelled with deuterium ln single positions of the allylic side chain. In single positions of the allylic side chain
Authors: Monti D. , Gramatica P. , Manitto P. 
Published: October 2006

Abstract[γ‐2H2]Estragole was synthesized via vinylation of 4‐ methoxy‐ [methylene‐2H2]‐benzyl chloride; [β‐2H]estragole via reduction of 3‐(p‐anisyl)‐propyne with bis‐3‐methyl‐2‐butylborane (obtained from LiAl2H4, BF3 etherate and 2‐methyl‐2‐butene) [α‐2H]estragole via reduction of the tosylhydrazone of 4‐methoxy‐[formyl‐2H]‐cinnamaldehyde with NaBH3CN.
A method for the preparation of 14C‐labeled carboxylic acids. Synthesis of 6,11‐dihydro[b,e]thiepin‐11‐one‐3‐yl acetic 14C‐acid
Authors: Parnes Howard 
Published: October 2006

AbstractAn example of a potentially general method for the preparation of 14C‐carboxylic acids based on the carbonation of an α‐lithiated carboxylate is described. This procedure requires only the unlabeled analog of the desired 14C‐acid as the precursor. The possibility of carrying out the selective decarboxylation of a malonic acid derivative with loss of only the unlabeled carboxyl group is described.
Photosynthetic preparation of galactose‐13C6 and glycerol‐13C3 using a marine red alga
Authors: Kollman V. H. , Gregg C. T. , Whaley T. W. , London R. E. , Hanners J. L. 
Published: October 2006

AbstractThe photosynthetic preparation of D‐galactose‐13C6 and glycerol‐13C3 from Gigartina corymbifera is described. The red marine algae biosynthesize the galactoside 2‐hydroxy‐1‐(hydroxymethyl)ethyl α‐D‐galactopyranoside (galactosylglycerol) during photosynthesis. The galactoside was isolated from an alcohol extract by an acetylation procedure and hydrolyzed to D‐galactose and glycerol. The average enrichment of the isolated products was 55 mol % 13C while the actual enrichment of newly synthesized material, determined by 13C nmr, was 80 mol % 13C after a photosynthetic period of 48 hr during which 90 mol % 13CO2 was administered. Thirty percent of the administered carbon was recovered in the products. The distribution of 13C in the galactose and glycerol was shown to be uniform by 13C nmr.
Syntheses du Diiodo 125I Practolol : Un Nouveau β‐Bloquant Potentiel
Authors: Pilichowski Jean‐François , Godeneche Denise 
Published: October 2006

AbstractLa synthèse d'un dérivé du Practolol marqué par 125I est décrite. En vue d'études métaboliques et pharcocinétiques, nous avons préparé le di 125I practolol avec un rendement de 11 % et une activité spécifique de 5 mCi/mmole.
The synthesis of some tritiated 5‐substituted uracil derivatives
Authors: Barr P. J. , Jones A. S. , Walker R. T. , Bohá L. 
Published: October 2006

AbstractThe synthesis of 5‐[3H‐ethynyl]uracil and 5‐acetyl[6‐3H]uracil in good yield and of a medium specific activity ( > 40 mCi/mmol) is described. The compounds are necessary for following the incorporation of these and other derived 5‐substituted uracils into DNA and also for studying the metabolism and mode of action of their deoxynucleosides, some of which possess antiviral properties.
Synthesis of carbon‐14 labeled 3‐phenylpropoxyguanidine cyclohexylsulfamate
Authors: Hsi Richard S. P. 
Published: October 2006

AbstractThis report describes the synthesis of carbon‐14 labeled 3‐phenylpropoxyguanidine cyclohexylsulfamate from barium [14C]‐carbonate. The product is labeled at the 3‐position of the propyl chain, adjacent to the phenyl ring.
Preparations of deuterium labelled guvacine and isoguvacine
Authors: Christensen Søren Brøgger , Krogsgaard‐Larsen Povl 
Published: October 2006

AbstractThe preparations of guvacine hydrochloride, in which a proton in position 2 (11) and protons in positions 2 and 5 (10) are selectively exchanged by deuterium, and of [2,6‐2H]isoguvacine hydrobromide (14a) are described. The deuterium labelled guvacine salts 10 and 11 were synthesized by triethylamine catalyzed exchange of hydrogen for deuterium in methyl N‐nitroso‐1,2,5,6‐tetrahydropyridine‐3‐carboxylate (3) followed by denitrosation and hydrolysis. Treatment of N‐nitroso‐1,4,5,6‐tetrahydropyridine‐3‐carboxylic acid with methanolic thionyl chloride gave 3,4,5,6‐tetrahydropyridin‐3‐on ketoxime. Compound 14a was prepared by sodium borodeuteride reduction of 4‐ethoxycarbonyl‐1‐methylpyridinium iodide (12) followed by N‐demethylation and hydrolysis of the intermediate.
Synthese Du Tertiobutyl‐2 dinitro‐4,6 Phenol Noyau‐14C (U) (“Dinoterbe” Noyau‐14C)
Authors: Noel Jean‐Pierre , Pichat Louis , Benakis Achille 
Published: October 2006

Abstract(U‐14C) Phenol and isobutene under pressure in presence of aluminium phenoxide gave in 60 % yield a mixture of (ring U‐14C) 2‐t‐butylphenol (50 %) and (ring U‐14C)‐2,6‐di‐t‐butylphenol (10 %) which were separated by column chromatography on silicagel. Each t‐butylphenol was nitrated under appropriate conditions to give an 35 % overall yield of (ring‐U‐14C)‐4,6‐dinitro‐2‐t‐butylphenol : specific activity : 27.4 mCi/mMol which was proved by TLC and HPLC to be 99 % radiochemically pure.
Specific tritiation onto C‐2 and C‐5 positions of histidine ‐ containing peptide. Application to thyroliberin
Authors: Levine‐Pinto H. , Pradelles P. , Morgat J. L. , Fromageot P. 
Published: October 2006

AbstractSpecific methods of tritium labelling onto C‐2 and (or) C‐5 positions of the imidazole ring were successfully applied to thyroliberin (TRF, L‐Glu‐L‐His‐L‐Pro‐NH2).Diazocoupling by diazotized sulphanilic acid and iodination by iodine monochloride of the histidyl residue were chosen to prepare precursors and to quantify the distribution of tritium atoms which were introduced.Catalytic hydrogenolysis in the presence of tritium gas of 5‐iodohistidine2 ‐ and 2(4‐sulfophenylazo)histidine2 ‐ derivatives allowed to label these positions with specific radioactivities of 30 Ci and 25 Ci/mmole respectively. For comparison thyroliberin tritiated by direct catalytic exchange is labelled essentially onto C‐2 with a specific radioactivity of 30 Ci/mmole.
Synthesis of (4‐hydroxy‐3‐methoxyphenyl)‐α, α, β, β‐tetradeutero ethylamine
Authors: Ehrhardt J. D. 
Published: October 2006

AbstractA five step synthesis of α, α, β, β‐d4‐3 methoxytyramine is described with an overall yield of 45% starting from methyl 4‐benzyloxy‐3‐methoxy benzoate.
Synthesis of deuterated and tritiated apogossypol
Authors: Powers Larry J. , Dorsett Preston H. 
Published: October 2006

AbstractApogossypol with deuterium or tritium in the 8 and 8′ positions can be synthesized by the base catalyzed deformylation of gossypol. The position of the labeling is established by the pmr spectrum of the material derived from the reaction of deuterium oxide and sodium deuteroxide. The specific activity of the tritiated material prepared from tritium oxide and sodium hydroxide is 110m Ci/m Mole. The methods described are also useful for the synthesis and storage of small quantities of unlabeled apogossypol.
Synthesis and quality control of long‐chain 18F‐fatty acids
Authors: Knust Ernst Joachim , Schüller Manfred , Stöcklin Gerhard 
Published: October 2006

AbstractIntroduction of fluorine‐18 into various positions of long‐chain fatty acids is described. The potential heart and liver radiopharmaceuticals 16‐18F‐hexadecanoic acid, 17‐18F‐heptadecanoic acid, 2‐18F‐, and (9,10)‐18F‐stearic acid have been prepared by nucleophilic F‐for‐Br exchange in the melt of the corresponding bromofatty acid methylesters in acetamide, followed by alkaline or acid hydrolysis. In the case of 17‐18F‐hepta‐decanoic acid saturation yields of about 30% have been obtained at an optimum reaction temperature of 150 °C and about 1 mg of KF‐carrier.
Preparation of carbon‐14 labelled guazatine (1,17‐BIS‐ [14C]‐guanidino‐9‐azaheptadecane triacetate)
Authors: Hudson H. R. , Pianka M. , Powroznik L. , Lynch V. P. 
Published: October 2006

Abstract1,17‐Bisguanidino‐9‐azaheptadecane triacetate(Guazatine)has been prepared with carbon‐14 labelling of the guanidine carbon atoms, by interaction of 1,17‐diamino‐9‐azaheptadecane with S‐methyl‐ 14C ‐isothiouronium sulphate. The initial product was purified by precipitation as the carbonate which was then dissolved in aqueous acetic acid to give a 6 % solution of the triacetate, with specific activity of 20.8 μCi mmol−l.
Radioactively labelled epoxides. Part III. Tritium labelled steroid 16α, 17α‐epoxides
Authors: Sparrow Alan J. , Bindel Ulla , Oesch Franz 
Published: October 2006

AbstractTritium labelled (17‐3H) 16α, 17α‐epoxy‐androst‐4‐en‐3‐one and 16α, 17α‐epoxy‐estra‐1,3,5(10)‐trien‐3‐ol have been prepared on a large scale (200‐300 mg amounts) with efficient (i.e. activity of product exactly predictable) introduction of label. The preparative method is very inexpensive, since the tritium derives from tritiated water, the steroid starting materials are readily available, and high yields are obtained in all steps.
The preparation of 5′‐iodo‐125I‐Δ8‐THC; a radioligand for the radioimmunoassay of cannabinoids
Authors: Pitt Colin G. , Seltzman Herbert H. , Setzer Susan R. , Williams David L. 
Published: October 2006

AbstractNucleophilic exchange of 5′‐iodo‐Δ8‐THC and sodium iodide‐125 afforded 5′‐iodo‐125I‐Δ8THC with a maximum specific activity of 42 Ci/mmole. The specific activity could be increased to at least 100 Ci/mmole by iodide‐125 displacement of the corresponding 5′‐tosylate. A hapten 5′‐carboxy‐14C‐Δ9‐THC, for use in conjunction with this radioligand, was synthesized from 5′‐bromo‐Δ8‐THC.
Preparation of [14C]Acetamidino‐insulin
Authors: Matsuo Mitsuyoshi , Yamauchi Hirose , Ooyama Toshiro , Orimo Hajime 
Published: October 2006

Abstract[14C]Acetamidino‐insulin was synthesized by acetamidination of insulin with methyl [14C]acetimidate hydrochloride. The acetamidino‐insulin contains two main components, which can be separated by DEAE‐cellulose column chromatography. They correspond to glycineA‐1 ‐ PhenylalanineB‐1 ‐ Nε ‐ lysineB‐29 ‐ [14C]acetamidino‐insulin and glycineA‐1 ‐ Nε ‐ lysineB‐29 ‐ [14C]acetamidino‐insulin. These immunological and biological activity was compared with that of native insulin.
Synthesis of double 15N‐labeled nitramines: N‐nitropiperidine and N‐nitrodimethylamine
Authors: Bulusu S. , Autera J. , Axenrod T. 
Published: October 2006

AbstractDouble 15N‐labeled N‐nitropiperidine and N‐nitrodimethylamine have been conveniently prepared by oxidation of the corresponding nitrosamines. Dimethylamine‐15N was commercially available while the required piperidine‐15N was synthesized from cyclopentanone via the Schmidt ring‐expansion procedure using potassium azide‐1‐15N, followed by hydride reduction of the resulting 2‐piperidinone‐15N.
Radiolysis of 131I‐O‐iodohippurate: A kinetic study
Authors: Hotte C. E. , Ice R. D. , Flynn G. L. 
Published: October 2006

AbstractAlthough radiolytic decomposition of several radiopharmaceuticals has exhibited apparent first‐order kinetics, the dependence of decomposition on drug concentration precludes a first‐order rate process. A kinetic study of the decomposition of 131I‐o‐iodohippurate in aqueous solution was carried out to accurately assess the dependence of radiopharmaceutical decomposition on absorbed radiation dose, initial radiopharmaceutical concentration and, in addition, on the concentration of added free radical inhibitors. The fraction of 131I‐o‐iodohippurate remaining, (A/Ao), was found to decrease exponentially with increased absorbed radiation dose. The radiolytic decomposition rate, however, exhibited a Langmiurian relationship with respect to the initial concentration of the radiopharmaceutical present (Ao) and the initial concentration of free‐radical inhibitor present (Io).magnified imagewas derived to characterize these dependencies and demonstrated good correlation with experimental results. This equation may be of value in assessing the radiolytic stability of other radiopharmaceuticals.
The synthesis of C‐2 isotopically labeled optically pure warfarin and phenprocoumon
Authors: Porter William R. , Kunze Kent , Valente Edward J. , Trager William F. 
Published: October 2006

AbstractOptically pure isotopically labeled phenprocoumon was prepared from resolved phenprocoumon via ring opening and decarboxylation followed by recarboxylation with suitably labeled (13C, 14C) diethyl carbonate and ring closure. A similar procedure was followed for the preparation of optically pure isotopically labeled warfarin after protection of the side chain carbonyl group by formation of an ethylene dithioketal derivative. The protecting group was quantitatively removed after incorporation of label by treatment with mercuric acetate.
Synthesis of [2‐14C] tetramethyluric acids
Authors: Citroreksoko P. S. , Petermann J. , Wanner H. , Baumann T. W. 
Published: October 2006

Abstract[2‐14C]1,3,7,9‐, 0(2),1,7,9‐ and 0(8),1,3,7‐Tetramethyluric acid were prepared by methylation of [2‐14C]uric acid with dimethyl sulfate at pH 9. The yield after repeated (3x) purification by TLC was 44.9%, 4.4% and 6.3% respectively.
A synthesis of DL‐erythro‐2‐(4‐benzylpiperidino)‐1‐(4‐hydroxyphenyl)‐[1‐14C]propan‐1‐OL L‐(+)‐tartrate
Authors: Allen J. 
Published: October 2006

AbstractThe preparation of DL‐erythro‐2‐(4‐benzylpiperidino)‐1‐(4‐hydroxy‐phenyl)‐[1‐14C]propan‐1‐ol L‐(+)‐tartrate, Ifenprodil tartrate (Vadilex ®) from barium [14C]carbonate is described. The product was obtained in 29.2 % radiochemical yield and at a specifie activity of 47.6 mCi/mmol. This was diluted to 2 and 1 mCi/mmol for metabolism and distribution studies in man. The radiochemical purity of the diluted product exceeded 99 %.
Synthesis of S‐benzyl‐DL‐[1‐13C]cysteine and its incorporation into oxytocin and [8‐arginlne]vasopressin and related compounds by total synthesis. Separation of diastekeoisomers by partition chromatography and HPLC
Authors: Hruby Victor J. , Viswanatha V. , Yang Young C. S. 
Published: October 2006

AbstractS‐Benzyl‐DL‐[1‐13C]cysteine was prepared from Na13CN by a three step synthesis and converted to the t‐butyloxycarbonyl derivative which was suitable for use in peptide synthesis. This compound was incorporated into the 1 and 6 positions of a variety of oxytocin and [8‐arginine]vasopressin derivatives and analogues via total synthesis using the solid phase method. The compounds were separated and purified by partition chromatography on Sephadex and their purity was checked by high pressure liquid chromatography. The compounds synthesized include [1‐hemi‐[1‐13C]cystine]oxytocin, [1‐hemi‐D‐[1‐13C]‐cystine]oxytocin, [1‐hemi‐[1‐13C]cystine, 8‐arginine]vasopressin, [1‐hemi‐D[1‐13C]cystine, 8‐arginine]vasopressin, [6‐hemi‐[1‐13C]cystine]oxytocin, [6‐hemi‐D‐[1‐13C]cystine]oxytocin, [1‐hemi‐D‐[1‐13C]cystine, 3‐D‐leucine]‐oxytocin, and [1‐hemi‐[1‐13C]cystine, 3‐D‐leucine]oxytocin.
A simple, rapid procedure for the preparation of deuterium‐labelled testosterone
Authors: Gaskell Simon J. , Finlay Elizabeth M. H. 
Published: October 2006

AbstractA simple and rapid procedure for the preparation of [16,16‐2H2]‐and [16,16,17‐2H3]testosterone of high isotopic purity is described. [16,16‐2H2]DehydrOepiandrosterone is obtained by base‐catalysed exchange; reduction of the 17‐keto group using lithium aluminium hydride or lithium aluminium deuteride is followed by selective enzymic oxidation of the 3β‐hydroxy function with concomitant Δ5 to Δ4 isomerisation. The incorporation of deuterium in intermediates and products is established by gas chromatographic‐mass spectrometrie analyses of parent compounds and alkylsilyl derivatives. Deuterium labels in the 16 and 17 positions of testosterone are shown to be non‐labile under strongly acidic and basic conditions.
Synthesis of clonidine and 1,3‐dimethylclonidine labelled at specific positions with deuterium and carbon‐13
Authors: Hughes Helen , Baillie Thomas A 
Published: October 2006

AbstractThe synthesis is reported of a number of analogues of clonidine and 1,3‐dimethylclonidine labelled specifically and in high isotopic purity with deuterium and carbon‐13. 2,6‐Dichloro[4‐2H1] aniline and 2,6‐dichloro‐[3,4,5‐2H3]Janiline were employed to prepare compounds substituted in the aromatic ring with one and three atoms of deuterium, respectively, while the use of appropriate derivatives of ethylenediamine led to products in which the imidazol idine ring was labelled with carbon‐13 or deuterium.
A new method for labelling 11β‐hydroxy steroids: Synthesis of 18‐2H‐corticosteroids
Authors: Green Michael J. , Shue Ho‐Jane , Bartner Peter , Morton James B. , Youngstrom Richard E. , Meinwald Jerrold 
Published: October 2006

AbstractA new method for labelling 11β‐hydroxy steroids is described. The procedure involves specifically placing the label on the angular C13 methyl group via the photolysis of the 11β‐nitrite ester (Barton reaction) and reaction of the resulting C18 radical with PhS‐2H in situ. Incorporations of 2H were 30‐40% for 9α‐H, 12‐21% for 9α‐F and <5% for 9α‐Cl corticosteroids. The extent of labelling was measured by mass spectrometry and the position of labelling was confirmed as C18 for two compounds by dmr, cmr and pmr spectroscopy.
Synthesis of perdeuterio‐N‐(1‐oxyl‐2,2,6,6‐tetramethyl‐4‐piperidinyl)maleimide, a highly sensitive spin probe
Authors: Venkatarmu Sindhaghatta D. , Pearson Donald E. , Beth Albert H. , Perkins Ray C. , Park Charles R. , Park Jane H. 
Published: October 2006

AbstractPerdeuterio‐N‐(1‐oxyl‐2,2,6,6‐tetramethyl‐4‐piperidinyl)‐maleimide has been prepared to improve sensitivity and resolution in its ESR spectrum. The synthesis involved modifications of procedures known for the corresponding protonated analog. Spectral data are presented for the product to establish isotopic purity. A five‐fold enhancement of the ESR signal for the title compound relative to the proton counterpart has been observed.
An improved synthesis of 5,5‐dideuterocyclophosphamide
Authors: Jarman M. , Taylor G. N. 
Published: October 2006

AbstractA high yielding synthesis of 5,5‐dideuterocyclophosphamide is described which involves the base catalysed deuterium exchange of 3‐hydroxypropionitrile and subsequent medium pressure catalytic hydrogenation to yield 1‐amino‐2,2‐dideuteropropan‐3‐ol. This compound is condensed with N,N‐bis(2‐chloroethyl)‐phosphoramidic dichloride to yield pure 5,5‐dideuterocyclophosphamide which is readily isolated as a crystalline monohydrate.
Labelling of neuroleptic butyrophenones. III. Synthesis of 2′‐amino‐4′‐fluoro‐4‐[4‐hydroxy‐4‐(3‐trifluoromethylphenyl)piperidino‐2‐14C] ‐ butyrophenone
Authors: Nakatsuka Iwao , Kawahara Kazuo , Yoshitake Akira 
Published: October 2006

Abstract2′‐Amino‐4′ ‐fluoro‐4‐(4‐hydroxy‐4‐) (3‐trifluoromethylphenyl) ‐ piperidino‐2‐14Cbutyrophenone [ID‐4708‐ (piperidine‐14C]), a neuroleptic agent, was synthesized for use in metabolic studies. The synthesis was achieved by the reaction scheme shown in Fig. 1. 1‐Benzyl‐4‐piperidone‐2‐14C was prepared by Mannich reaction of paraformaldehyde‐14C with ethyl acryloylacetate and benzylamine, followed by treatment with hydrochloric acid, in 65% yield. Grignard reaction of the product with 3‐trifluoromethylphenyl‐magnesium bromide followed by hydrogenolysis gave 4‐hydroxy‐4‐(3‐trifluoromethylphenyl)piperidine‐2‐14C (8), which was condensed with 3‐(6‐fluoro‐2‐methyl‐3‐indolyl) propionic acid to give the 3‐indolylpropionylpiperidine‐14C (10). Conversion of 10 by reduction, oxidation and then hydrolysis led to ID‐4708‐(piperidine‐14 C) (1) in the overall yield of 9.6% from paraformaldehyde‐14C.
Carbon‐14‐labeled 2,3,7,8‐ and 1,2,7,8‐tetrachlorodibenzofuran
Authors: Gray Allan P. , McClellan W. J. , Dipinto V. M. 
Published: October 2006

AbstractBoth 2,3,7,8‐ and 1,2,7,8‐ tetrachlorodibenzofuran ‐U14C, specific activity 57 mCi/mmol, have been obtained in low yield but at < 98% purity via Pschorr cyclization of o‐phenoxyaniline ‐U14C, chlorination of the resultant dibenzofuran and separation of the tetrachloro isomers by hplc. The lower yields obtained in the Pschorr cyclization of “hot” o‐phenoxyaniline in comparison with the “cold” material are postulated to result from enhanced homolytic relative to heterolytic cleavage of the “hot” diazonium ion leading to a “hot” free radical which polymerizes. The completely anomalous results observed in the attempted palladium acetate‐mediated cyclization of diphenyl ether‐ U14C are likewise interpreted in terms of the intervention of a “hot” free radical.
Preparation of uniformly 14C‐labeled and 13C‐enriched catechol and hydroquinone via phenol
Authors: Chew Edward H. , Heys J. Richard 
Published: October 2006

AbstractCatechol‐U‐14C and hydroquinone‐U‐14C were prepared from phenol‐U‐14C by mononitration followed by chromatographic separation of o‐ and p‐nitrophenol‐U‐14C. The nitrophenols were separately hydrogenated, and the resulting aminophenols were converted by diazotization followed by hydrolysis to the title diols. Phenol‐U‐14C was synthesized efficiently from benzene by nitration, reduction, diazotization and hydrolysis. A similar series of reactions beginning with benzene‐U‐13C gave phenol, catechol and hydroquinone containing more than 88% total carbon‐13.
Direct isotope determination of drugs labeled with stable isotopes of hydrogen, carbon, and nitrogen by field desorption mass spectrometry
Authors: Bahr U. , Schulten H.‐R. 
Published: October 2006

AbstractBy recording the molecular ion group with repetitive magnetic scanning and accumulation of the mass spectra in a multichannel analyser field desorption mass spectrometry was used to determine the isotopic abundances of three widely used drugs in their unlabeled and stable‐isotope labeled forms. The label content and statistical distribution of 2H, 13C and 15N in analogs of an antitumor agent, cyclophosphamide and one of its metabolites 4‐ketocyclophosphamide and of two analgesics antipyrine and carbamazepine were investigated. Using nanogram amounts of sample the precision and accuracy of the measurements achieved were below ±1% on an absolute basis.
Synthesis of isotopically labelled salicylates
Authors: Hawkins D. R. , Pryor R. W. 
Published: October 2006

Abstract[13C‐carboxyl]Salicylic acid has been prepared by carbonation of 2‐benzyloxybromobenzene followed by reductive debenzylation. Deuterium and tritium labelled salicylic acid and 2H2/13C‐salicylic acid were prepared by reduction of the 3,5‐dibromo derivatives using Raney Ni‐Al. Deuterium labelled salicylic acid containing up to four deuterium atoms was prepared by catalytic exchange with Raney Ni‐Al in 5% NaOD/D2O.