bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and evaluation of potential tumor localizing radiopharmaceuticals: Technetium‐99m iminodiacetic acid derivatives of sulfanilamides
Authors: Hunt F. C. , Maddalena D. J. , McLaren A. B. , Wilson J. G. 
Published: October 2006

AbstractTo exploit the tissue affinity of compounds for radiopharmaceutical purposes, attachment of chelating groups is usually necessary to facilitate technetium‐99m binding and transport.The chelating group, iminodiacetic acid, previously used to modify lidocaine for hepatobiliary radiopharmaceuticals, was attached to several antibiotic sulfanilamides known to concentrate in certain transplanted animal tumors.These iminodiacetic acid derivatives were labelled with technetium‐99m by the stannous chloride reduction method.Biodistribution of the 99mTc labelled compounds in tumor bearing rats revealed no specific concentration in the tumors and localization mainly in the excretory organs.The results indicate that, as in the case of lidocaine, conversion of the sulfanilamides into iminodiacetic acid derivatives and chelation with technetium leads to an altered biodistribution and loss of biological specificity.
Preparation of methadone and some congeners labeled with tritium in the aromatic rings
Authors: Kepler J. A. , Sparacino C. M. , Howe C. R. , Austin R. D. 
Published: October 2006

Abstract[diphenyl‐2,2′‐3H2]Methadone with specific activity of 8‐30 Ci/mmol was prepared by reductive dehalogenation of 6‐dimethylamino‐4, 4‐bis(2‐chlorophenyl)‐3‐heptanone with carrier‐free tritium gas. The labeled congeners (−)‐α‐acetylmethadol, (−)‐α‐acetyl‐N‐normethadol, and (−)‐α‐acetyl‐N,N‐dinormethadol were prepared from (+)‐[diphenyl‐2,2′‐3H2]methadone.
Synthesis of n‐heptyltrichlorosilane 7‐13C for preparation of labeled chromatographic surfaces
Authors: Gangoda M. E. , Gilpin R. K. 
Published: October 2006

AbstractThis report describes the synthesis of carbon‐13 labeled n‐heptyltrichlorosilane from 13C methyl iodide. The product is labeled at the 7‐position of the alkyl chain in a 24% yield.
Tritiation of mianserin
Authors: Favier J. S. , Wallaart J. , Kaspersen F. M. 
Published: October 2006

AbstractLabelling of mianserin in the N‐methyl group or the piperazine ring results in changes in the physical properties of the molecule. Using deuterium it is shown that mianserin can be labelled at metabolically stable positions without introducing isotope effects by exchange under alkaline conditions (at C10) or by reductive dechlorination (at C12 or C13).[13‐3H]‐mianserin with a specific activity of 16 Ci. mmol−1 was synthesized by reductive dehalogenation of 13‐chloromianserin using 3H2. The position of the label was confirmed by 3H‐NMR spectroscopy.
Radiohalogenation of non activated aromatic compounds via aryltrimethylsilyl intermediates
Authors: Wilbur D. S. , Anderson K. W. , Stone W. E. , O'Brien H. A. 
Published: October 2006

AbstractThe utility of aryltrimethylsilyl derivatives to regiospecifically introduce carrier and no‐carrier‐added quantities of radiobromine and radioiodine into certain aromatic rings has been demonstrated. Using trimethylsilyltoluenes as a model system for aromatic rings that are not highly activated, conditions for the rapid and efficient incorporation of radiobromine and radioiodine were found. Reaction conditions necessary for the radiobrominations were very mild; however, the slower radioiodinations required elevated temperatures or highly acidic conditions.
Synthese de [14 C] ‐ sulfometuron methyle et de [14 C] ‐ metsulfuron methyle
Authors: Bastide Jean , Badon Robert 
Published: October 2006

Abstract[[2‐14C] pyridimyl] sulfometuron methyl and [2‐14C) ‐ triazinyl] metsulfuron methyl, two sulfonylurea herbicides has been prepared by multistep synthesis. [2‐14C] 2‐amino‐4,6 dimethyl pyrimidine was obtained by two steps from [14C] guanidine and [2‐14C] 2‐amino‐4 methoxy‐4 methyl 1,3,5 triazine was obtained from [14C] cyanamide. The two herbicides were prepared by condensation of heterocycle with methyl‐2 (sulfonylisocyanate) benzoate.
Use of kinetic isotope effects in enzymatic oxidation of D‐[6‐3H]galactose for increasing its molar activity
Authors: Akulov G. P. , Korsakova N. A. , Kudelin B. K. 
Published: October 2006

AbstractLarge kinetic isotope effects have been observed in D‐[6‐3H]galactose enzymatic oxidation reactions catalyzed by the galactoseoxidase. It is possible to use these effects for considerable increase of the molar activity of D‐galactose labelled with tritium in the position 6.
Aryltrimethylammonium trifluoromethanesulfonates as precursors to aryl [18F]fluorides: Improved synthesis of [18F]GBR‐13119
Authors: Haka Michael S. , Kilbourn Michael R. , Leonard Watkins G. , Toorongian Steven A. 
Published: October 2006

AbstractAromatic nucleophilic substitution of various trimethylammonium trifluoromethanesulfonates with [18F]fluoride has been evaluated. Fluorinations were studied over a temperature range of 45–165°C, with decay corrected yields ranging from 20–80%. [18F]GBR 13119, 1‐[2‐{(4‐[18F]fluorophenyl)(phenyl)methoxy}ethyl]‐4‐(3‐phenylpropyl)piperazine, a potential radio‐tracer for the dopamine uptake system, has been prepared in no‐carrier‐added form from 4‐N,N,N,‐trimethylaniliniumphenylmethanone trifluoromethanesulfonate. Purification by solid‐phase techniques yielded the product in 20% decay corrected radiochemical yield and >98% radiochemical and chemical purity without HPLC.
Synthesis of tritium‐labelled enantiomers of myo‐inositol 1,4,5‐trisphosphate
Authors: Marecek James F. , Prestwich Glenn D. 
Published: October 2006

AbstractBoth natural D‐ and L‐enantiomers of myo‐Ins(1,4,5)P3 were synthesized with specific activities 14–16 Ci/mmol. A suitable inositol derivative was resolved as the diastereomeric camphanate esters, and the chiral inositol derivatives were oxidized to the protected inosose. Reduction of each chiral ketone with sodium borotritide and manipulation of protecting groups gave the enantiomeric [1‐3H]‐2,3,6‐tri‐0‐benzyl‐myo‐inositols in 55% radiochemical yield. Phosphorylation with tetrabenzylpyrophosphate and complete hydrogenolytic debenzylation provided the separate D‐myo and L‐myo‐ [1‐3H]‐Ins(1,4,5)P3 enantiomers in 30% radiochemical yield.
A method for the preparation of labelled gossypol by the incorporation of 14C acetate
Authors: Guadalupe Rojas M. , Stipanovic Robert D. , Williams Howard J. , Vinson Bradleigh 
Published: October 2006

AbstractCarbon‐14 14labelled gossypol has been prepared by incorporating 1,2‐14C acetate in the growth medium of cold shocked cotton (Gossypium arboreum) seedling roots. Unlabelled gossypol was added during the purification procedure to aid crystallization; thus, from 350 seedling roots, 25 uCi sodium (1,2‐14C) (45–60 mCi/mmol) acetate and 800 mg of unlabelled gossypol; 350 mg of labelled gossypol (1900 dpm/mg) was isolated.
Determination of isotopic purity and position in deuterated methyl behenate
Authors: Liu R. H. , Bailey A. V. 
Published: October 2006

AbstractIn the course of preparing peanut oil type triglycerides for metabolism studies, methyl esters of deuterated behenic acid, a saturated 22‐carbon fatty acid, with zero, two, and six deuterium atoms were synthesized. The specific positions of deuterium atoms and the completion of deuteration in the products were characterized by gas chromatography/mass spectrometry methods.
A convenient synthesis of deuterated leukotriene A4 methyl ester
Authors: Bestmann Hans Jürgen , Meese Claus O. , Röder Thomas 
Published: October 2006

Abstract2,2,3,3‐[2H4]‐1‐Iodopentane (8b) was prepared in four steps from propargyl alcohol and used in the C‐alkylation of the THP‐protected 3‐butyne‐1‐ol (10). Subsequent protective group removal of 11b, semi‐deuteration of the acetylenic alcohol 12b, and further transformation by known methods afforded the labelled key reagent 3,4,6,6,7,7‐[2H6]‐(Z)‐(3‐nonen‐1‐yl)triphenylphosphonium iodide (3b). Wittig olefination of epoxy dienal 2 with the ylide generated from 3b completed the convenient synthesis of hexadeuterated leukotriene A4 methyl ester (1b).
Synthesis of carbon‐14 labeled PD 117,302 and PD 126,212, potential new analgesic agents
Authors: Hays Sheryl J. , Hicks James L. , Butler Donald E. , Huang C. C. 
Published: October 2006

AbstractTwo kappa opiate agonists 1 and 2 have been labeled from bromo‐[1‐14C]‐acetic acid and sodium [1‐14C]acetate respectively.
Labelled compounds of interest as antitumour agents. Part II (1). Synthesis of 2H and 3H isotopomers of RSU 1069 and Ro 03‐8799 (pimonidazole)
Authors: Webb Paul , Threadgill Michael D. 
Published: October 2006

Abstract2H‐ and 3H‐Labelled RSU 1069 and Ro 03‐8799 (pimonidazole) have been synthesised by reduction of 1‐(3‐chloro‐2‐oxopropyl)‐2‐nitroimidazole with the appropriately labelled sodium borohydride, followed by ring‐closure of the chlorohydrins and treatment of the resulting epoxides with aziridine or piperidine. In both cases, the specific activities were 200 mCi mmol−1 and the radiochemical yields were 86%. The parent compounds are radiosensitisers of hypoxic tumour cells.
Synthesis of [5‐14C]pentostatin, an antileukemic agent and potent adenosine deaminase inhibitor
Authors: Woo Peter W. K. , Lee Helen T. 
Published: October 2006

AbstractReaction of triethyl ortho[14C]formate (2) with 2‐amino‐1‐(5‐amino‐1H‐imidazol‐4‐yl)ethanone dihydrochloride (1) in the presence of molecular sieves 4A gave 6,7‐dihydro[5‐14C]imidazo[4,5‐d][1,3]diazepin‐8(3H)‐one hydrochloride monodimethyl sulfoxide (3) (radiochemical yield, 60%). The latter was persilylated with bis(trimethylsilyl)trifluroacetamide (4) and glycosylated with 2‐deoxy‐3,5‐di‐O‐p‐toluoyl‐α‐D‐erythro‐pentofuranosyl chloride (6) to give a mixture from which the 3‐N‐β‐glycosylated product 8 was isolated by chromatography and crystallization (13%). Deprotective saponification with methanolic sodium methoxide and subsequent sodium borohydride reduction of the 8‐keto function gave a (R,S)‐mixture from which the desired (R)‐isomer, [5‐14C]pentostatin (11), was isolated by preparative HPLC over a C18 column, desalting with Diaion‐HP20, and subsequent crystallization (39%).
Tritium labeling of simple 7‐membered ring compounds
Authors: Hiltunen J.  , Peng C. T.  , Yang Z. C.  
Published: October 2006

AbstractSeven‐membered ring compounds, from cylcoheptane to complex ring structures containing heteroatoms, substituents and fused phenyl rings, were labeled with tritium, using activated and adsorbed tritium. The 7‐membered ring structures are generally stable towards reactions with tritium, which allows compounds like 1‐benzosuberone, 1‐aza‐2‐methoxy‐1‐cycloheptene, iminostilbene and clozapine to be labeled to reasonably high specific activities. The best method varies greatly from compound to compound. By optimizing the labeling conditions and use of efficient support exceptionally good results can be obtained. The Pd‐on‐alumina support gives consistently higher specific activity and less radioimpurity than other supports. Even molecules containing carbon‐halogen bond and hydrogen bound to nitrogen can usually be labeled with tritium at stable positions and without dehalogenation.
Synthesis of carbon‐14 and tritium labeled methylprednisolone suleptanate
Authors: Stolle Wayne T , Runge Thomas A. , Hsi Richard S. P. 
Published: October 2006

AbstractMethylprednisolone suleptanate was initially labeled with tritium in the A‐ring of the steroid portion of the molecule, and with carbon‐14 at both carboxylic carbons of the suberic acid portion of the side chain. However these labels proved to lack total metabolic stability after administration to rats. Subsequently a second pair of labeled methylprednisolone suleptanates was synthesized, with tritium at C‐7 in the B‐ring of the steroid and carbon‐14 exclusively at the carboxamide carbon in the side chain. These labeled compounds showed excellent metabolic stability of both the tritium and carbon‐14 labels, and should be well suited for conducting drug disposition studies.
Preparation of deuterated naphthalenes, anilines, m‐toluidines, and anisoles by reductive dehalogenation of the corresponding halogenated derivatives with raney Cu‐Al alloy in an alkaline deuterium oxide solution
Authors: Tashiro Masashi , Tsuzuki Hirohisa , Tsukinoki Takehito , Mataka Shuntaro , Nakayama Kouji , Yonemitsu Tadashi 
Published: October 2006

AbstractFour deuterated naphthalenes, ten deuterated anilines, three deuterated m‐toluidines, and five deuterated anisoles were prepared in high isotopic purities from the corresponding halo‐substituted derivatives by the reductive dehalogenation with Raney Cu‐Al alloy in an alkaline deuterium oxide solution.
Synthesis of 3H‐labeled sympathomimetic amines for neuronal mapping
Authors: Van Dort Marcian E. , Gildersleeve David L. , Wieland Donald M. 
Published: October 2006

AbstractThe synthesis of two tritium labeled sympathomimetic amines, (R)‐(‐)‐phenylephrine and (1R,2S)‐(‐)‐meta‐hydroxyephedrine, is described. The tritium label was introduced into the aromatic ring in the final step by catalytic reductive dehalogenation of the corresponding iodinated precursor. (1R,2S)‐(‐)‐meta‐hydroxyephedrine was synthesized in four steps from commercially available metaraminol. A novel HPLC purification method provided the labeled compounds in a medium ready for direct animal evaluation. Chemical and radiochemical purity was ≥98%; specific activity was ≥ 22 Ci/mmol.
A rapid and efficient synthesis of 2‐deoxy‐2‐[18F]fluoroacetamido‐D‐mannopyranose and ‐D‐galactopyranose
Authors: Tada Masao , Oikawa Atsushi , Iwata Ren , Sato Kazunori , Kubota Kazuo , Fujiwara Takehiko , Sugiyama Hiroshi , Abe Yoshinao , Sato Tachio , Matsuzawa Taiju , Takahashi Hiromu , Wakui Akira , Ido Tatsuo 
Published: October 2006

AbstractRapid and efficient syntheses of 2‐deoxy‐2‐[18F]fluoroacetamido‐D‐mannopyranose (1) and ‐D‐galactopyranose (2), respectively, starting from [18F]fluoride and ethyl bromoacetate are described. [18F]Fluoride was produced by the 18O (p, n) 18F nuclear reaction using the cyclotron. The total times required for synthesis of (1) and (2) are ca. 80 min. The radiochemical yield and purity of (1) are an 18% and ≥98%, respectively. Compound (2) is also synthesized with the same radiochemical yield and purity.
Radiolabeling of proteins with radioisotopes of copper using p‐carboxyalkylphenylglyoxal bis‐(4N‐methylthiosemicarbazone) (TSC) bifunctional chelates
Authors: McPherson D. W. , Umbricht G. , Knapp F. F. 
Published: October 2006

AbstractA series of p‐carboxyalkylphenylglyoxal and p‐carboxyalkyl‐1,2‐diketo‐bis‐(N4‐methylthiosemicarbazone) bifunctional ligands (TSC) have been prepared and evaluated for use in binding radioisotopes of copper to antibodies. We have developed an improved synthesis of the requisite α‐ketoaldehyde and 1,2‐diketone substrates used for derivatization to the bis‐TSC bifunctional chelates. This approach utilizes a modified Kornblum method and provides a simple alternative to the usual method for fabrication of the 1,2‐bis‐TSC ligands, which avoids the use of highly toxic selenium dioxide for oxidation of substituted acetophenones to 1,2 dicarbonyl compounds. The overall yields of the bis‐TSC chelates using this procedure were 8‐60%. The effects of the alkyl chain length and substitution on the C‐2 position on p‐carboxyalkylphenyl‐1,2‐diketo bis‐TSC bifunctional chelate for attaching radioisotopes of copper to proteins were studied. Following complexing copper‐64 or copper‐67 to the bis‐TSC chelate, the acid moiety of the TSC chelate was activated as the tetrafluorophenyl ester. The copper‐labeled activated TSC chelate was attached to bovine serum albumin under mild conditions in 3% to 40% yield. These studies have demonstrated that the shorter chain analogues of the TSC chelates from the 1,2‐diketones give the highest radiolabeling yields.
Preparation of enantiomerically‐active deuterium‐labelled ibuprofen
Authors: Chen Ching‐Shih , Copeland Debra , Harriman Shawn , Liu Yeuk‐Cheun 
Published: October 2006

AbstractThe chemoenzymatic preparation of optically‐active [3,3,3‐2H3]‐ibuprofen and [2‐2H]‐ibuprofen are described.
Synthesis of 2,2‐dimethyl‐13C2‐propionitrile‐1‐13C and its conversion to triply carbon‐132labeled dowco 429 insecticide
Authors: Roth G. A. , McClymont E. L. 
Published: October 2006

AbstractA convenient synthesis of triply carbon‐13 labeled 2,2‐dimethyl‐13C2‐propionitrile‐1‐13C is described. The synthetic sequence begins with commercially available propionic acid‐1‐13C and methyl iodide‐13C with the application of a sequential dianion alkylation. The 2,2‐dimethyl‐13C2‐propionitrile‐1‐13C was carried on to triply labeled DOWCO 429 insecticide for use in residue and metabolism studies.
Synthesis of (3R)‐3‐(4‐fluorophenylsulfonamido)‐1, 2, 3, 4‐tetrahydro‐9‐[4‐3H]carbazolepropanoic acid
Authors: Pleiß Ulrich , Radtke Martin , Schmitt Peter 
Published: October 2006

Abstract(3R)‐3‐(4‐Fluorophenylsulfonamido)‐1, 2, 3, 4‐tetrahydro‐9‐[4‐3H]carbazolepropanoic acid ([3H]BAY u 3405) (5) was synthesized by catalytic reduction of (3R)‐3‐(4‐fluorophenylsulfon‐amido)‐4‐oxo‐1, 2, 3, 4‐tetrahydro‐9‐carbazolepropanoic acid (4) with tritium. The precursor (4) was prepared by esterification and following oxidation of BAY u 3405 with 2, 3‐dichloro‐5, 6‐dicyano‐p‐benzoquinone. 3H NMR analysis of the final product showed the formation of [4α‐3H]BAY u 3405 and [4ß‐3H]BAY u 3405 in a ratio of 1: 1.
An improved synthesis of dideuterated thioridazine with the label in the piperidine ring
Authors: Mohammad T. , Hawes E. M. , McKay G. , Midha K. K. 
Published: October 2006

Abstract2‐(2‐Hydroxyethyl)‐1‐methyl [6,6‐2H2]piperidine was obtained by a new route from 2‐(2‐hydroxyethyl)‐piperidine. This enabled dideuterated (±)‐thioridazine to be obtained by an improved approach. The key steps involved ruthenium tetroxide oxidation of the N, O‐diacetylated starting material and subsequent lithium aluminum deuteride reduction of O‐acetylated 2‐(2‐hydroxyethyl)‐6‐pieridinone.
Isolation and characterisation of high molecular weight [3H]hyaluronic acid
Authors: Chabreček P. , Šoltés L. , Kállay Z. , Fügedi A. 
Published: October 2006

AbstractA high‐performance gel permeation chromatographic separation method was developed for the isolation and characterisation of high molecular weight [3H]hyaluronic acid. The molecular characteristics of the labelled sample were MW=3.92x105 Da, MW/Mn=1.55.
Myocardial imaging agents: Synthesis, characterization and evaluation of [(Z) and (Z,E)‐(1‐[82br]bromo‐1‐penten‐5‐yl)]triphenylphosphonium cations
Authors: Srivastava P. C. , Knapp F. F. , Callahan A. P. , Goldstein B. M. 
Published: October 2006

AbstractThe phosphonium compounds, [(Z) and (Z/E)‐(1‐bromo‐1‐penten‐5‐yl)]triphenylphosphonium iodides (yield, 65–70%) and the corresponding bromine‐82‐labeled analogues have been prepared as potential myocardial imaging agents. The 2/1 isomer composition of the Z/E mixture has been confirmed by single crystal X‐ray analysis. The radiobrominated (Z)‐isomer and (Z/E)‐mixture both show high heart uptake and high heart/blood ratios in rats. These data suggest that the bromine‐75 and bromine‐76‐labeled agents could be good candidates for myocardial imaging using positron emission computed tomography.
High‐yield nitration of benzene in the synthesis of 15N‐labelled nitrobenzene, acetanilide, and diphenylamine
Authors: Konior Raymond J. , Yang Ling , Walter Robert I. 
Published: October 2006

AbstractLabelled H15NO3 was used as the least‐cost source of nitrogen label to prepare nitrobenzene by reaction of acetyl nitrate with excess benzene. This labelled product was subsequently converted to acetanilide‐15N and diphenylamine‐15N.
A simple and high‐yield synthesis of (S)‐BZM, (R)‐BZM AND (S)‐IBZM for the preparation of (S)‐123I‐IBZM
Authors: Bobeldijk M. , Verhoeff N. P. L. G. , Vekemans J. A. J. M. , Buck H. M. , Van Doremalen P. A. P. M. , Van Hoof J. J. , Janssen A. G. M. 
Published: October 2006

Abstract(S)‐2‐Hydroxy‐6‐methoxy‐N‐[(1‐ethyl‐2‐pyrrolidinyl)methyl]benzamide ((S)‐BZM; (S)‐5a), the precursor of (S)‐2‐hydroxy‐3‐123I‐iodo‐6‐methoxy‐N‐[(1‐ethyl‐2‐pyrrolidinyl)methyl]benzamide ((S)‐123I‐IBZM) was synthesized via a simple method and in high yield starting from 2,6‐dimethoxybenzoic acid (1a). N‐Hydroxysuccinimide/dicyclohexyl‐carbodiimide (DCC) was used as activating system in the reaction of 1a with (S)‐2‐aminomethyl‐1‐ethylpyrrolidine (3a).
Synthesis of N‐(α,α,α‐tri[18F]fluoro‐m‐tolyl)piperazine. A potent serotonin agonist
Authors: Angelini G. , Speranza M. , Wolf A. P. , Shiue C.‐Y. 
Published: October 2006

AbstractN‐(α,α,α‐tri[18F]fluoro‐m‐tolyl)piperazine (6), a serotonin agonist, was synthesized from 3‐nitro‐α,α,α‐trichlorotoluene (1) and H[18F] + Sb2O3 in four steps in 27% overall radiochemical yield in a synthesis time of ˜ 3 hours.
Synthesis of optically pure 13C‐labelled propionate from alanine by asymmetric hydrolysis using porcine kidney acylase
Authors: Iida Katsumi , Kajiwara Masahiro 
Published: October 2006

AbstractSodium (R)‐[2‐2H,3‐13C]propionate, sodium (S)‐[2‐2H,3‐13C] propionate, sodium (R)‐[3‐13C]‐2‐fluoropropionate, and sodium (S)‐[3‐13C]‐2‐fluoropropionate were synthesized from D[(S)]‐[3‐13C]alanine and L[(R)]‐[3‐13C]alanine, which were obtained by asymmetric hydrolysis using acylase from porcine kidney.
The synthesis of o‐ and p‐[18F]fluorobenzyl bromides and their application to the prepatation of labeled neuroleptics
Authors: Hatano Kentaro , Ido Tatsuo , Iwata Ren 
Published: October 2006

AbstractThe syntheses of o‐ and p‐ [18F]fluorobenzyl bromides as labeled synthons were described. They were obtained from nitrobenzaldehyde via a three step synthesis that exhibited good yield. The preparation of [18F]fluororinated analog of a benzamide neuroleptic, cis‐N‐[(2RS, 3RS)‐1‐[18F]fluorobenzyl‐2‐methylpyrrolidin‐3‐yl] ‐5‐chloro‐2‐methoxy‐4‐methylaminobenzamide, via N‐benzylation with the synthons was also mentioned.
Preparation of deuteriated succinic acids
Authors: Tashiro Masashi , Tsuzuki Hirohisa , Isobe Shin‐Ichiro , Goto Hideyuki , Ogasahara Shoji , Mataka Shuntaro , Yonemitsu Tadashi 
Published: October 2006

AbstractSuccinic [2,3‐2H2]‐ and [2,2,3,3‐2H4]‐acids were prepared from maleic anhydride and dimethyl fumarate, and acetylene dicarboxylic acid and its dimethyl ester by treatment with CuAl and Ni‐Al alloys in 10% NaOD‐D2O in 95% to 100% isotopic purity. The succinic 2H4 acid having high isotopic purity was also obtained on the hydrolysis of 1,2‐ethanedinitrile with alkaline deuterium oxide. Based on the 1H{2H} spectra analysis of N‐(o‐biphenyl)[2,3‐2H2]succinimide, it was elucidated that the Raney alloy reduction with alkaline deuterium oxide proceeds stepwise.
Synthesis of tritium‐labeled (+)loxistatin (E‐64d)
Authors: Huang Zhenya , McGowan Eleanor B. , Detwiler Thomas C. 
Published: October 2006

AbstractThe enantioselective synthesis of tritium‐labeled (+)loxistatin is described. N‐Boc‐[U‐3H]L‐leucine was the starting material for the threestep synthesis. Boc‐leucine was amidated with isoamylamine. The Bocgroup was removed with 4N HCl in dioxane. Transesterification with ethyl p‐nitrophenyl‐L‐trans‐epoxysuccinate led to (+)loxistatin with a specific radioactivity of 4.4 mCi/mmole and a radiochemical purity of > 97%.
A facile and regiospecific tritiation of sphingosine: Synthesis of (2S,3R,4E)‐2‐amino‐4‐octadecene‐1,3‐diol‐1‐3H
Authors: Toyokuni Tatsushi , Nisar Mohammad , Dean Barbara , Hakomori Sen‐Itiroh 
Published: October 2006

AbstractAn easy technique for introduction of tritium into the 1‐position of sphingosine was developed, employing regiospecific oxidation of the primary hydroxy group followed by reduction with NaB3H4. An improved preparation of N,N‐dimethylsphingosine and its quaternization are also described.