bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of carbon‐14 labeled 1,4‐benzodiazepines. IV. Carbon‐13 and carbon‐14 labeled 8‐chloro‐1‐(2‐dimethylamino)ethyl‐6‐phenyl‐4H‐s‐triazolo[4,3‐a][1,4]‐benzodiazepine tosylate
Authors: Hsi Richard S. P. , Stolle Wayne T. 
Published: October 2006

AbstractCarbon‐13 and carbon‐14 labeled forms of the title compound have been prepared from the correspondingly labeled forms of 8‐chloro‐1‐methyl‐6‐phenyl‐4H‐s‐triazolo[4,3‐a][1,4]benzodiazepine (3)Alprazolam is the generic USAN name for this compound.
. A modified and more convenient version of the previously reported procedure for preparing 3 is described.
Preparation of biphenyl‐2,2′,3,3′,5,5′,6,6′‐2H8
Authors: Clark Alice M. , Davis Patrick J. , Smith Robert V. 
Published: October 2006

AbstractBiphenyl‐2,2′,3,3′,5,5′,6,6′‐2H8 was prepared from biphenyl‐d10. Initial bromination of biphenyl‐d10 followed by hydrogenolysis of the 4,4′‐dibromobiphenyl‐d8 with lithium aluminum hydride gave the desired product in 40% overall yield.
A novel synthesis of α‐N‐methyl‐14C‐DL‐asparagine by generation of methylamine‐14C insitu
Authors: Tsou Hwei‐Ru 
Published: October 2006

AbstractA method is described by which methylamine‐14C is qenerated from its hydrochloride by N,N‐diisopropylethylamine in the presence of maleamic acid to produce the title compound in high yield.
Synthesis of 4‐amino‐3,2′ ‐dimethylbiphenyl‐3‐methyl‐14C and 4‐amino‐2′‐methylbiphenyl‐2′‐methyl‐14C
Authors: El‐Bayoumy Karam , Hecht Stephen S. 
Published: October 2006

AbstractThe syntheses of 4‐amino‐3,2′‐dimethyl‐biphenyl‐3‐methyl‐14C, a potent carcinogen and mutagen, and 4‐amino‐2′‐methylbiphenyl‐2′‐methyl‐14C, an analogue having weaker activity, are described. In both cases, label was introduced with Cu14 CN.
Application of spin labeling to drug assays. I. Synthesis of 2,2,6,6‐tetramethylpiperidin‐4‐one‐1‐oxyl‐15N‐d16
Authors: Yost Yul , Polnaszek Carl F. , Mason Ronald P. , Holtzman Jordan L. 
Published: October 2006

AbstractSpin labeled drugs can be utilized for immunoassays and determining the fraction of free drug in serum. To improve the sensitivity we have synthesized triacetonamine‐15N‐d17 by cyclization of phorone‐d14 with 15ND3. Phorone‐d14 was obtained by condensation of acetone‐d6. Triacetonamine‐15N‐d17 gave Tempone‐15N‐d16, a nitroxide with just two absorption peaks on the ESR spectrum, whereas Tempone gives 3 peaks. The contribution to line width of methylene and methy1 hydrogens of Tempone is evaluated by appropriate substitution of protium with deuterium.
Synthesis of 14C‐labelled metoprolol
Authors: Chaudhuri Naba K. , Ball Thomas J. 
Published: October 2006

AbstractThe synthesis of 14C‐labelled metoprolol, a new antihypertensive drug is described. Starting from p‐bromoanisole and 14CO2, 14C‐labelled p‐methoxyphenylethyl alcohol was prepared by the following sequence of reactions: MeO‐C6H4‐Br→ MeO‐C6H4‐14COOH→ MeO‐C6H4‐14CH2OH→ MeO‐C6H4‐14CH2Cl→ MeO‐C6H4‐14CH2‐CN→ MeO‐C6H4‐14CH2‐COOH → MeO‐C6H4‐14CH2‐CH2OH. Heating with 47% HBr gave [14C]‐p‐hydroxyphenylethyl bromide which on treatment with methanol under alkaline condition was converted into [14C]‐p‐hydroxyphenylethyl methyl ether. Reaction with epichlorhydrin followed by isopropylamine gave [14C]‐metoprolol.
14C‐labelling of optically active fenvalerate, (S)‐α‐cyano‐3‐phenoxybenzyl (s)‐2‐(4‐chlorophenyl)‐3‐methylbutyrate (II)
Authors: Kanamaru Hiroshi , Kamada Takeshi , Nakatsuka Iwao , Mohri Zen‐Ichi , Okamura Taeko , Yoshitake Akira 
Published: October 2006

Abstract(S)‐α‐Cyano‐3‐phenoxybenzyl (S)‐2‐(4‐chlorophenyl)‐3‐methylbutyrate (fenvalerate Aα), an optically active insecticide, was labelled with carbon‐14 individually at the benzyl ring (1a) and the chlorophenyl ring (1b) for use in metabolic studies. Ullmann reaction of 3‐methylphenol‐14C6 (2) with bromobenzene followed by oxygen oxidation gave 3‐phenoxybenzoic‐14C6 acid (4). Reduction of 4 followed by potassium dichromate oxidation of the alcohol (5) gave 3‐phenoxybenzaldehyde‐14C6 (6). Condensation of 6 with (S)‐2‐(4‐chlorophenyl)‐3‐methylbutanoyl chloride and sodium cyanide afforded fenvalerate A‐(benzyl‐14C6), which on optical resolution gave 1a in 29% yield from 2. Isopropylation of 4‐chlorophenyl‐14C6‐acetonitrile (9) followed by hydrolysis gave 2‐(4‐chlorophenyl‐14C6)‐3‐methylbutyric acid which on optical resolution gave the (S)‐acid (12). Esterification of the acid with α‐cyano‐3‐phenoxybenzyl bromide yielded fenvalerate A‐(phenyl‐14C6), which was resolved to give 1b in 9% yield from 9.
High specific activity [phenyl‐3h]benzylpenicillin N‐ethylpiperidine salt
Authors: Rosegay Avery 
Published: October 2006

AbstractThe N‐ethylpiperidine salt of [3H]penicillin G (31 Ci/mmole) was prepared and stored in acetone solution at −15°. The radiochemical purity, as determined by reverse isotope dilution assay, decreased about 12% over a period of one month, less than that expected for an aqueous solution.
Deuteration of the racemate and the (2S)‐(+)‐enantiomer of the antiarrhythmic agent disopyramide, 4‐diisopropylamino‐2‐(2‐pyridyl)‐2‐phenylbutyramide
Authors: Nelson Wendel L. , Rees Janine A. , Hulinek Sandra J. 
Published: October 2006

AbstractDeuteration of disopyramide, 4‐diisopropylamino‐2‐(2‐pyridyl)‐2‐phenylbutyramide, was accomplished in an excess of 2H2SO4 at 125–135°C. Incorporation of 2‐4 atoms of deuterium occurs with 65% recovery of disopyramide. At higher temperatures (150°C) greater incorporation of deuterium occurs, but substantial decomposition reduces the recovery of disopyramide to 25%.
Synthesis of 1‐pyrenyloxirane‐3,6,8‐3H1
Authors: McCaustland Daniel J. , Susàn Alexander B. , Wiley James C. 
Published: October 2006

AbstractThe syntheses of 1‐pyrenyloxirane‐3,6,8‐3H1, 7, and its precursor, pyrene‐1,3,6,8‐3H1, 4, are described. The synthesis pathway includes a novel preparation of 4 from 1‐pyrenyllithium and tritiated water in theoretical yield.
Preparation of 2‐iodomorphine for use in radioimmunoassay
Authors: Mason P A , Law B , Ardrey R E 
Published: October 2006

AbstractA method is described for the preparation of 125iodomorphine. The structure of this compound was confirmed by synthesis of 127iodomorphine and subsequent mass spectral studies. 125Iodomorphine has proved to be chemically very stable and has been shown to be bound avidly by a morphine antiserum. It should, therefore, prove to be very useful for the development of a morphine radioimmunoassay.
The synthesis of four specifically deuterated trans‐4‐octenes
Authors: Shaw G. John 
Published: October 2006

Abstracttrans‐4‐Octene‐1,1,1‐2H3; −2,2‐2H2; −3,3‐2H2 and −4‐2H1 have been synthesized. The electron impact mass spectra and isotopic enrichment of these compounds have been measured and are reported.
Tritium isotope effect in birch keductions
Authors: Egli Peter 
Published: October 2006

AbstractD‐2‐Aminophenylacetic acid (1) (phenylglycine, PG) was subjected to a Birch reduction in the presence of tritiumion. A substantial, but relatively low isotope effect, kH/kT = 3.51, was found for the reduction reaction. The resulting D‐2‐amino‐[3,6‐3H](1,4‐cyclohexadien‐1‐yl)acetic acid (2) (dihydrophenylglycine, DHPG) aromatized rapidly by a secondary radio‐decomposition to afford mainly P[3H]G, resulting in the predicted loss of half the tritium. When a carbon‐14 label was used, the DHP[14C]G aromatized about seven times faster than DH[3H]PG normalized to the same specific activity, when stored as a solid. This difference is in good agreement with the ratio predicted based on the difference in decay energies for the two isotopes.
Synthesis of deuterium labeled C19‐Δ16 steroids
Authors: Thompson R. H. , Pearson A. M. 
Published: October 2006

AbstractDeuterium labeled forms of 5α‐androst‐16‐en‐3‐one, 3α‐hydroxy‐5α‐androst‐16‐ene, 3β‐hydroxy‐5α‐androst‐16‐ene, 3β‐hydroxy‐5, 16‐androstadiene and 4, 16‐androstadien‐3‐one were prepared to serve as internal standards in quantitative analysis of C19‐Δ16 steroids by mass spectrometric reverse isotope dilution. In general, the methods used employed deuterium exchange of activated hydrogens adjacent to carbonyl carbons followed by reaction steps which isolated the newly incorporated deuterium. Removal of any remaining exchangeable deuteriums was the final step in each reaction sequence.
Synthesis of optically active deuterium labelled serine and glycylserine derivatives
Authors: Kovacs J. , Jham G. , Hui K. Y. 
Published: October 2006

AbstractOptically active α‐deuterated serine dipeptide active ester derivatives were prepared to study the racemization mechanism. N‐Acetyl‐O‐benzyl‐DL‐serine, 1, was converted to 5(4H)‐oxazolone 2 and deuterated with CH3‐COOD in α‐position. 5(42H)‐Oxazolone 3 was converted to Z‐(α2H)‐L‐Ser(Bzl)‐OHThe following abbreviations are used: benzyloxycarbonyl = Z; tert‐butyloxycarbonyl = Boc; benzyl = Bzl; pentachlorophenyl = Pcp; dicyclohexylcarbodiimide = DCC; dicyclohexylurea = DCU, tetrahydrofuran = PHF; thin layer chromatography = TLC
7, after opening the 5(42H)‐oxazolone ring with D2O, removal of the N‐acetyl group, treatment with carbobenzoxy chloride and resolution with (+)‐α‐phenylethylamine. Pentachlorophenyl ester 8 of 7 was converted to Z‐Gly‐(α2H)‐L‐Ser(Bzl)‐OPcp, 10, after removal of carbobenzoxy group by catalytic hydrogenation. The deuterium content of the intermediates was determined by mass spectrometry.
Isolation of (−)‐menthol‐14C and (+)‐neomenthol‐14C
Authors: Haut Stephen A , Core Margaret T. 
Published: October 2006

AbstractUniformly labelled (−)‐menthol‐14C and (+)‐neomenthol‐14C were isolated and purified from the oil of peppermint plants grown in a 14CO2 chamber by preparative high performance liquid chromatography. This procedure is much simplier than previous methods and allows for large amounts of labelled oil to be processed.
The synthesis of 7‐chloro‐1‐methyl‐5‐phenyl‐1, 3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one‐5‐14C and 7‐nitro‐1‐methyl‐5‐(2′‐fluorophenyl)‐1, 3‐dihydro‐2H‐1,4‐benzodiazepin‐2‐one‐5‐14C
Authors: Kaegi H. H. , Burger W. , Bader C. J. 
Published: October 2006

AbstractTwo benzodiazepines, Diazepam and Flunitrazepam, labeled with carbon‐14 in position 5 of the diazepine ring have been synthesized. Use of a condensation between iminochlorides and 14C‐benzonitriles, followed by exhaustive methylation of the resulting quinazolines and hydrolyses is described. This sequence of reactions allows the preparation of the intermediate o‐methylamino‐benzophenones in good yields.
An investigation of the kinetics of formamidine sulfinic acid (FSA) degradation in the preparation of technetium‐99m radiopharmaceuticals
Authors: Jette D. C. , Scott J. R. , Sitarz W. 
Published: October 2006

AbstractTechnetium‐99m glucoheptonate complex was prepared using formamidine sulfinic acid (FSA) as a reducing agent. The fraction of technetium which was complexed to glucoheptonate remained at less than 20 percent for the first 10 minutes. After 20 minutes, the complexed fraction was greater than 95 percent and remained at this level after 24 hours. The lag phase was attributed to the kinetics of the base catalyzed degradation of FSA to urea and bisulfite. The overall rate of FSA degradation was determined and found to be dependent on the concentration of base and the initial concentration of FSA. The rate of production of one of the degradation products, urea, was also measured and found to be dependent on the concentration of base, but independent of the initial FSA concentration. A reaction scheme for the degradation of FSA was proposed and the reaction rate constants for the products of this reaction were determined.
Preparation of [15‐3h] gibberellin‐A3
Authors: Lischewski Manfred , Adam G. 
Published: October 2006

AbstractThe cyclobutane compounds 2, 3, 4 or 5, which represent in position‐15 functionalized gibberellin derivatives, reacted with 3H2O under mild alkaline conditions in a retroaldol‐like cleavage to give diacetyl[15‐3H]gibberllin‐A3‐7‐aldehyde (6) and the isomeric compound 7.In respect of a second possibility of 15‐tritiation, diacetyl‐GA3‐7‐aldehyde (1) was irradiated with UV‐light in benzene/3H2O to form diacetyl [15 α‐3H] GA3‐7‐aldehyde (6a).Oxidation and deacetylation of 6 afforded [15‐3H]gibberellin‐A3(8).
Synthesis and purification of carbon‐14 labelled 1, 1‐hexamethylene‐bis [5‐(4‐chlorophenyl)biguanide] (chlorhexidine), ‘Hibitane’
Authors: Burns J. 
Published: October 2006

AbstractTwo syntheses of [14C] chlorhexidine (‘Hibitane’) with the label specifically incorporated in two separate molecular positions are described. Ring labelled chlorhexidine prepared from p‐chloro[U‐14C]aniline was obtained with a molar specific activity of 27.9 mCi/mmol. Chain labelled material, where the 14C label was incorporated in the 1 and 6 positions of the hexamethylene bridge, was prepared from [1, 6 14C]‐adiponitrile, with a molar specific activity of 11.5 mCi/mmol. Several methods of purification are described.
Synthetic heparinoids labelled with 125I and 35S
Authors: Sederel L. C. , Kolar Z. , Van Der Does L. , Bantjes A. 
Published: October 2006

AbstractThe labelling of a water‐soluble synthetic polyelectrolyte, having anticoagulant activity, has been studied. The polyelectrolyte is derived from cis‐1,4‐polyisoprene and contains N‐sulfate and carboxylate groups. [125I]‐Iodination of the polyelectrolyte, using the Chloramine‐T method and an electrolytic method, resulted in a [125I]‐labelled polyelectrolyte from which release of the label occurred. Resulfation of a partially desulfated polyelectrolyte with a [35S]‐sulfur trioxide trimethylamine complex resulted in a [35S]‐labelled polyelectrolyte which showed no release of the label.
Deuterium exchange in sesamol
Authors: Hill Richard K. , Vaidya Niteen A. , Morton Gerald H. 
Published: October 2006

AbstractTrifluoroacetic acid‐catalyzed exchange of sesamol in 2H2O results in rapid exchange of H‐6 and slower exchange of H‐2. The deuterium atoms introduced are retained during conversion to the methyl and allyl ethers.
75Se‐labelled bile acid analogues
Authors: Monks R. , Thomas I. L. 
Published: October 2006

AbstractThe synthesis of several 75Se‐labelled bile acid analogues* is described in which selenium‐75 replaces a carbon methylene group at different positions in the C‐17 side‐chain. Procedures for the synthesis of necessary nonradioactive intermediates are included. Some results for the organ distribution of the compounds in rats are given. 23‐[75Se] selena‐25‐homocholic acid and its glycine and taurine conjugates show particularly good properties for the study of the enterohepatic circulation of bile acids.
Direct incorporation of [11C]carbon dioxide for labeling bioactive molecules. An application to [11C] labeled tamoxifen
Authors: Ram Siya , Spicer Leonard D. 
Published: October 2006

AbstractA one‐pot synthesis of [11C] labeled tamoxifen has been developed via reductive carboxylation. In this approach, [11C]CO2 is reacted with the N‐trimethylsilyl derivative of desmethyltamoxifen, followed by in situ sodium bis (2‐methoxyethoxy)aluminum hydride reduction, to afford impure [11C] labeled tamoxifen, which, on purification over a basic alumina‐silica gel column, provided pure [11C] tamoxifen in excellent radiochemical yield (65% to 84%) and radiochemical purity (>99%). The specific activity of [11C]tamoxifen was 250–400 Ci/mmol at the end of bombardment.
Synthesis and labelling with 18F of an MK 801 analogue: [18F]5‐(β‐fluoruethyl)‐10,11‐dihydro‐5H‐dibenzocycloheptene‐5,10‐imine
Authors: Denis A. , Crouzel C. 
Published: October 2006

AbstractThe 5‐(β‐fluoro)ethyl analogue 1 of MK 801 2 was synthesized and labelled with 18F in order to visualize the NMDA receptors by positron emission tomography. A tosyloxy precursor 3 was synthesized in 8 steps from dibromodibenzosuberone; the nucleophilic substitution of the tosyl group of 3 by the K18F/Krytofix 2,2,2 complex in CH3CN gave [18F] 1 in 25% radiochemical yield with a specific activity of 40 GBq/μmol (1 Ci/μmol).The major excitatory amino acids in mammalian brain CNS, L.glutamate and L. aspartate, have a neurotoxic activity mediated through excitatory synaptic receptors such as N‐Methyl‐D‐Aspartate (NMDA) receptor subtype. These excitotoxic amino acids have been implicated in several brain damages associated with epilepsy, anoxia‐ischemia and hypoglycemia (1). MK 801 [(+)5‐methyl‐10,11‐dihydro‐5H‐dibenzo‐cycloheptene‐5,10‐imine] 2 is a potent and non‐competitive antagonist of NMDA (2). MK 801 was shown, in animal models, to protect against hypoxic‐ischemic damage and NMDA neurotoxicity (3, 4). These results may have important implications for the treatment in man of stroke and neurodegenerative disorders. In order to visualize the NMDA receptors by positron emission tomography, the synthesis and the labelling with fluorine 18 (β+, t½ = 110 min) of the 5‐(β fluoro(ethyl 1 analogue of MK 801 2 was undertaken (Scheme I).
The synthesis of isotopically labeled retinoids
Authors: Liebman Arnold A. , Burger Walter , Malarek David H. , Serico Lucia , Muccino Richard R. , Perry Clark W. , Choudhry Satish C. 
Published: October 2006

AbstractRetinyl acetate (4a) has been prepared with a tritium label at the C‐11 and C‐12 positions by partial reduction of oxenin (1) with tritium gas followed by acetylation and rearrangement. Specific activities of up to 40 curies/mmole have been attained. By alkaline hydrolysis, retinol (5) has been obtained and derivatized as one of several retinyl esters or has been oxidized to all‐trans retinoic acid (6) having equally high specific tritium activities. From beta ionone (12), 13‐cis retinoic acid (10) has been elaborated in a variety of isotopically labeled forms. A key reaction in the sequence, the Wittig coupling of the triphenylphosphonium derivative of vinyl beta ionol (15a‐c) and the butenolide, 5‐hydroxy‐4‐methyl‐2(5H)‐furanone (8), provides access to 13‐cis retinoic acid and its 4‐oxo metabolite labeled with either isotopic hydrogen or carbon.
Studies on hindered phenols. III. Synthesis of (±)‐5‐[4‐(6‐hydroxy‐2, 5, 7, 8‐tetramethylchroman‐2‐yl‐methoxy) benzyl]‐5‐14C‐thiazolidine‐2, 4‐dione (14C‐labelled CS‐045)
Authors: Yoshioka T. , Aizawa Y. , Kanai T. , Fujita T. , Kawai K. 
Published: October 2006

AbstractA synthetic procedure for producing (±)‐5‐[4‐(6‐hydroxy‐2, 5, 7, 8‐tetramethylchroman‐2‐ylmethoxy) benzyl]‐5‐14C‐thiazolidine‐2, 4‐dione (14C‐labelled CS‐045) is described. The radiolabel is introduced using [5‐14C] thiazolidine‐2, 4‐dione, as shown in the scheme.
Synthesis of α‐ and γ‐tocopherols selectively labelled with deuterium
Authors: Hughes L. , Slaby M. , Burton G. W. , Ingold K. U. 
Published: October 2006

AbstractFour deuterium‐substituted α‐tocopherols (dideutero‐RRR, nonadeutero‐ambo, nonadeutero‐all‐rac and undecadeutero‐all‐rac) and a dideutero‐RRR‐γ‐tocopherol have been synthesized for use in studies of the biokinetics, bioavailability and metabolism of vitamin E.
Synthesis of L‐6‐[123I]iodo‐m‐tyrosine a potential spect brain imaging agent
Authors: Adam Michael J. , Ponce Yolanda Zea , Berry Joffre M. 
Published: October 2006

AbstractL‐6‐[123I]Iodo‐m‐tyrosine was synthesized by the direct iodination of L‐m‐tyrosine with [123I]‐NaI and Chloramine‐T. The product was purified by reverse phase HPLC to give the final product in 57% radiochemical yield with a radiochemical purity of greater than 97%.
The radiosynthesis of nca [O‐methyl‐11C]viqualine, through an N‐trityl‐protected intermediate, as a potential pet radioligand for 5HT re‐uptake sites
Authors: Pascali Claudio , Pike Victor W. , Turton David R. 
Published: October 2006

AbstractViqualine, {4‐[3‐[3(R)‐ethenyl‐4(R)‐piperidinyl]propyl]‐6‐methoxyquinoline}, has been labelled in the O‐methyl position with no‐carrier‐added (nca) carbon‐11 (t1/2 = 20.4 min; β+ = 99.8%) to provide a potential radioligand for PET studies of 5HT re‐uptake sites. Direct treatment of desmethyl‐viqualine with nca [11C]iodomethane gave [O‐methyl‐11C]viqualine as only a minor product. NMR data suggested that the dominant product is that from the [11C]alkylation of the competing piperidino‐nitrogen. Protection of this nitrogen with the trityl group, followed by treatment with nca [11C]iodomethane in dimethyl sulphoxide with sodium hydroxide as base, and then rapid deprotection by mild acid hydrolysis gave nca [O‐methyl‐11C]viqualine as the main crude product (27% radiochemical yield, decay‐corrected from [11C]iodomethane). Radiochemically and chemically pure nca [O‐methyl‐11C]viqualine was obtained by work up on C18 Sep‐pak followed by reverse phase HPLC. The radiosynthesis, including final formulation for i.v. administration, takes 56 min after producing the carbon‐11 as [11C]carbon dioxide by the 14N(p,α)11C reaction. This radiosynthesis illustrates the potential utility of the trityl group for the protection of nitrogen in rapid carbon‐11 radiochemistry.
Synthesis of deuterium labelled lorazepam
Authors: Köves G. J. 
Published: October 2006

AbstractSynthesis of 2H3‐lorazepam was achieved by modification of literature procedures for the unlabelled drug. The key step in the seven step procedure was the initial one where upon selective exchange of 2‐amino‐5,2′‐dichloro‐benzophenone was obtained in deuterated acids. Purifications were carried out by preparative HPLC. The 2H3‐lorazepam is suitable for use as an internal standard in GC‐MS‐NICI‐SIM quantitative analysis in forensic case work.
Preparation of bromine‐77 labelled monoclonal anti‐hPLAP antibody using chloramine‐T
Authors: Lambert Fabienne , Slegers Guido , Goethals Patrick 
Published: October 2006

AbstractA tumor‐associated monoclonal antibody, named 7E8 and raised against human placental alkaline phosphatase (hPLAP), is labelled with bromine‐77 by means of chloramine‐T. The paper describes optimum radiobromination conditions resulting in 34% radiochemical yield of labelled antibody with more than 90% immunoreactivity.
Asymmetric hydroboration‐oxidation of alkenes by means of deuterium or tritium labelled asymmetric monoalkylboranes
Authors: Burgos Alain , Kamenka Jean‐Marc , Moustier Anne‐Marie , Rousseau Bernard 
Published: October 2006

Abstract(2‐(1,3‐Dithianyl))myrtanylborane (MDBH2), a stable asymmetric monoalkylborane, was converted into deuterated or tritiated analogues used to prepare enantiomeric labelled alcohols from 1‐phenylcyclopentene with a high isotopic enrichment (90–95% for deuterium; 86–89% for tritium) and a high asymmetric induction (80% ee for deuterium; 75% ee for tritium).
High specific activity steroids I: 17α‐ethynylestradiol‐[9,11‐3H] and norethindrone‐[9,11‐3H]
Authors: Parnes Howard , Shelton Emma J. 
Published: October 2006

AbstractWe report herein the first high specific activity tritium labelled synthesis of the widely used oral antifertility agents ethynylestradiol (5) and norethindrone (9). These substances were prepared at a specific activity of 54 Ci/mmol, a figure which is 48 and 377 times greater than any previously described preparations of (5) and (9) respectively. Microscale conditions were developed for all the steps in the sequence, including the Birch reduction (1), so that the initially high level of enrichment usually achieved in the reduction of Δ9(11)‐estradiol 3‐methyl ether was retained in the final products.
Synthesis and separation of 3‐O‐Methyl‐2‐ and 6‐[18F]‐fluorodopa
Authors: Adam Michael J. , Jivan Salma 
Published: October 2006

Abstract3‐O‐Methyl‐2‐ and 6‐[18F]‐fluorodopa were synthesized in 8% radiochemical yield by the direct fluorination of a protected L‐dopa derivative with [18F]‐acetyl hypofluorite. The 2‐ and 6‐fluoro isomers were separated and purified by reverse phase HPLC.
Synthesis of [3H]pinoline, an endogenous tetrahydro‐ß‐carboline
Authors: Callaway J. C. , Morimoto H. , Gynther J. , Airaksinen M. M. , Williams P. G. 
Published: October 2006

AbstractPinoline (6‐methoxy‐1,2,3,4‐tetrahyro‐9H‐pyrido[3,4‐b]indole) is an endogenous ß‐carboline thought to be synthesized in the pineal gland from serotonin. It is a strong inhibitor of MAO‐A and can displace [3H]citalopram from the 5‐HT uptake site on human platelets in nM concentrations. The hydrochloride salt of 6‐MeO‐DHßC (6‐methoxy‐1,2‐dihydro‐9H‐pyrido[3,4‐b]indole), also a new compound, was synthesized as the immediate precursor to the title compound.