bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct syntheses of β‐hydroxyvaline and [4,4′‐2H6]‐β‐hydroxyvaline
Authors: Scott A. I. , Wilkinson T. J.
Published: October 2006

The anion of N,N‐dibenzylglycine ethyl ester was condensed with acetone to afford N,N‐dibenzyl‐β‐hydroxyvaline ethyl ester which was debenzylated and hydrolyzed to yield β‐hydroxyvaline in 72% overall yield. A variety of β‐hydroxyvalines labelled on the isopropyl group can be prepared by this procedure as shown by the preparation of [4,4′‐2H6]‐β‐hydroxyvaline from d6‐acetone.
Synthesis Of [11β‐3H]prostacyclin
Authors: Blair Ian A. , Hensby Christopher N. , Macdermot John
Published: October 2006

The synthesis of [11β‐3H]prostacyclin and [11β‐3H]6‐oxo‐prostaglandin F1α has been described. The strategy involved borotritide reduction of prostaglandin D2, followed by cyclic iodoether formation. Adenylate cyclase activation in a neuronal somatic cell hybrid and GC‐MS were used for the analysis of the target compounds. The ready acid catalysed ketal formation of [11β‐3H]6‐oxo‐prostaglandin F1α is noted.
Synthesis of 14C‐labelled isophosphamide
Authors: van Maanen J. M. S. , Griggs L. J. , Jarman M.
Published: October 2006

Isophosphamide labelled with 14C in the chloroethyl group attached to the exocyclic nitrogen has been synthesised by treatment of N‐3‐hydroxypropyl‐aziridine with phosphorus oxychloride and reaction of the resulting 2‐chloro‐3‐(2‐chloroethyl) tetrahydro‐2H‐1,3,2‐oxazaphosphorine‐2‐oxide with [1‐14c]‐2‐chloroethylamine.
Synthesis of 14C‐labelled 5‐hydroxy‐4‐keto‐valeric acid and 4, 5‐dioxo‐valeric acid
Authors: Tschesche Rudolf , Wirth Wolfgang
Published: October 2006

5‐Hydroxy‐4‐keto [4‐14C]valeric acid was prepared from 5‐amino [4‐14C]levulinic acid. The synthesis of 5‐hydroxy‐4‐keto [1‐14C]valeric acid (4) was achieved by Grignard reaction of 1‐benzyloxy‐4‐bromo‐2‐butanone ethylene acetal (1) with 14CO2 and subsequent removal of the protecting groups.

4,5‐Dioxo [1‐ or 4‐14C]valeric acid was made by oxidation of the α‐ketol group with cupric acetate.
Synthesis of 2,3‐dihydroxybenzoic acid ‐ (carboxyl‐14C)
Authors: Sundaram M. G.
Published: October 2006

2,3‐Dihydroxybenzoic acid‐(carboxyl‐14C) can be synthesized in high overall yield from commercially‐available 2,3‐dimethoxybenzoic acid. The synthetic route features the application of a Curtius rearrangement, the thermal decomposition of a carboxylic acid azide to an isocyanate. The method is suitable for the preparation of the title compound on both micro and semimicro scales.
Micro‐synthesis of radioleptophos labelled at five different sites
Authors: Zayed S. M. A. D. , Farghaly M. , Fakhr I. M. I. , Hassan A.
Published: October 2006

The micro‐procedure involved interaction of benzene with phosphorus trichloride followed by addition of sulphur. Phenyl dichlorophosphine sulphide was condensed with methanol to form 0‐methyl phenylthiophosphono‐chloridate which was allowed to react with the sodium salt of 4‐bromo‐2,5‐dichlorophenol to yield leptophos [O‐(4‐bromo‐2,5‐dichlorophenyl) 0‐methyl phenyl phosphonothioate]. Five radioactive leptophos compounds were prepared by substituting the cold chemicals with the appropriate radioactive precursor (32PCl3, 1‐14C‐benzene, 35S, 14C‐methanol or tritiated 4‐bromo‐2,5 dichlorophenol).
Preparation of deuterium‐labeled rutin by hydrogen exchange reaction
Authors: Hiraoka K. , Miyamoto T. , Baba S. , Furuta T.
Published: October 2006

Preparation of deuterium‐labeled rutin by hydrogen exchange reaction under alkaline condition is described. Hydrogens at positions 2′, 5′ and 6′ of rutin were replaced with deuteriums only on heating, while hydrogens at positions 6 and 8 were readily replaced at room temperature. On the basis of these findings rutin‐2′, 5′, 6′, 6, 8‐d5 was first prepared and then treated with alkaline water at room temperature to obtain rutin labeled with deuteriums at positions 2′, 5′ and 6′.
Synthesis of N‐(4‐pyridyl[14C]carbonylamino)‐1,2,[3H]3,6‐tetrahydropyridine and the mono‐labelled [14C]‐ and [3H]‐analogues
Authors: Mercer J. R. , Wiebe L. I. , Knaus E. E.
Published: October 2006

Reaction of isonicotinic [14C] acid hydrazide (1) with the Zinke salt (2) afforded N‐(4‐pyridyl [14C] carbonylimino)pyridinium ylide (3) in 81% chemical yield. Sodium borohydride reduction of 3 gave N‐(4‐pyridyl [14C] carbonylamino) −1,2,3,6‐tetrahydropyridine (4) in 60% chemical yield with a specific activity of 6.17 mCi mM−1. Alternatively reduction of N‐(4‐pyridylcarbonylimino) pyridinium ylide (5) using absolute ethanol and [3H]‐water as solvent yielded N‐ (4‐pyridylcarbonylamino)‐1,2,[3H]3,6‐tetrahydropyridine (9) in 52.6% chemical yield with a specific activity of 1.14 mCi mM−1. N‐4‐Pyridyl[14C]carbonylamino‐1,2,[3H]3,6‐ tetrahydropyridine (10) was similarly prepared by sodium borohydride reduction of 3 using absolute ethanol and [3H]‐water as solvent in 46% chemical yield with specific activities of 1.31 and 5.66 mCi mM−1 respectively for [3H] and [14C].
Preparation of 2,3,5,6‐tetrachloropyridine‐2,6‐14C
Authors: McKendry L. H.
Published: October 2006

An 88.6% yield of 2,3,5,6‐tetrachloropyridine‐2,6‐14C (8.99 mCi, 14.5 mCi/mmole) was obtained via chlorination of 2,6‐dichloropyridine‐2,6‐14C.
Synthesis of deuterated and tritiated derivatives of enflurane
Authors: Burke Terrence R. , Pohl Lance R.
Published: October 2006

Specifically deuterated derivatives of the inhalation anesthetic enflurane [2‐chloro‐1‐(difluoromethoxy)‐1,1,2‐trifluoroethane] have been synthesized by a facile base catalyzed exchange. Tritiated enflurane has also been synthesized by this procedure.
Synthesis of 14C‐labelled 4‐(2‐hydroxy‐3‐isopropylaminopropoxy)‐2‐methyl‐indole (mapindolol)
Authors: Illi V. O. , Heindl J. , Balzer J. , Schwartz W.
Published: October 2006

Mepindolol, a potent ß‐adrenoceptor blocking agent, was labelled with 14C by two different routes yielding the 2‐[14C]methyl and [2‐14C] products. While the first alternative was abandoned because of low overall yield, the latter route provided mepindolol with a specific activity of 2.06 GBq/mmole (55.8 mCi/mmole) and in a radiochemical yield of 40% starting from Ba14CO3.
Synthesis of 123mTe labeled fatty acids
Authors: Mills Stanley L. , Basmadjian Garo P. , Parker George R. , Ice Rodney D.
Published: October 2006

Four 123mTe labeled fatty acid analogues were synthesized: 17‐tellura‐9‐octadecenoic acid, 17‐tellura‐9‐nonadecenoic acid, 18‐methyl‐17‐tellura‐9‐nonadecenoic acid and 3‐tellura‐non‐adecanoic acid.

Tellurium‐123m metal was solubilized in water with NaBH4. The inorganic nucleophiles produced, NaHTe or Na2Te2 were reacted with 16‐bromo‐9‐hexadecenoic acid in a one or two step procedure to produce the sodium alkyl telluride. To this was added either methyl iodide, ethyl bromide or isopropyl bromide and the resulting 17‐tellura‐fatty acids isolated and formulated. Tellurium‐123m labeled 3‐tellura‐nonadecanoic acid was synthesized via the dihexadecanyl ditelluride or the sodium hexadecanyl telluride route.
Synthese De Phenyl‐1 Propenols Specifiquement Deuteries
Authors: Denhez Jean‐Pierre , Girault Gisèle , Dizabo Pierre
Published: October 2006

The synthesis of deuterated 1‐phenylpropénols is reported. The methods involve either Grignard reactions or selective reduction of α, β insaturated ketones. These ketones are obtained by degradation of ammonium salts of the Mannich bases.
The synthesis of [2‐3H2] taurine and [2‐3H2] hypotarine
Authors: Fellman J. H.
Published: October 2006

The synthesis of [2‐3H2]‐2‐aminoethanesulfonate [2‐3H]‐taurine by the reduction of cyanomethanesulfonic acid with tritium gas is described. The conversion of [2‐3H]‐taurine and its 14C and 35S isotopic forms to 2‐aminoethanesulfinate (hypotaurine) was accomplished by converting taurine to its corresponding sulfonyl chloride and reducing the latter with metallic zinc.
A convenient synthesis of NG‐mono[14C‐methyl]‐L‐arginine
Authors: Abou‐Gharbia M. , Paik W. K. , Swern D.
Published: October 2006

NG‐Mono[14C‐methyl]‐L‐arginine was prepared in a two‐step synthesis. N,S‐dimethylthiopseudouronium iodide [methyl‐14C] was prepared in excellent yield and afforded the labelled amino acid on coupling with L‐ornithine.
Synthesis of [8‐3H]Pentostatin
Authors: Putt Sterling R. , Hartman Jon D. , Showalter H. D. Hollis , Kepler John A. , Taylor George
Published: October 2006

Starting from 3‐(2‐deoxy‐β‐D‐erythro‐pentofuranosyl)‐6,7‐dihydroimidazo[4,5‐d][1,3]diazepin‐8(3H)‐one (4), the synthesis of both the R‐and S‐isomers of [8‐3H]pentostatin has been achieved. The separation of the desired R‐isomer in Ca. 24% overall chemical yield from the R, S‐mixture was effected by preparative reverse‐phase chromatography utilizing a C18 stationary support. Crystalline product of high specific activity (227 mCi/mmole) was obtained.
Synthese de l'acide nervonique 14C‐24 (acide cis‐tétracosène‐15 oïque 14C‐24)
Authors: Moriya T. , Pabiot M. , Pichat L.
Published: October 2006

Methyl iodide‐14C was condensed with 2‐(1‐lithio‐hept‐1‐yn‐6‐yl) 1,3‐dioxolanne 4 in presence of HMPT and benzene to give 2‐(oct‐2‐yn‐8‐yl‐1‐14C) 1,3‐dioxolanne 5.

Catalytic reduction of 5, followed by acid hydrolysis led to pelargonic aldehyde 9‐14C 7. Condensation of this aldehyde 7 with an excess of w‐carbomethoxy‐tetradecylidene), triphenyl phosphorane 11 produced methyl nervonate 24‐ 14C 12. The latter was isolated from its trans isomer by chromatography on a silver nitrate impregnated silicagel column. Finally, nervonic acid 24‐14C 13 was obtained by alkaline hydrolysis (specific activity : 52 mCi/mMole) with an overall yield of 7% based on methyl iodide‐14C.
Syntheses of astato compounds by melt method
Authors: Shiue C.‐Y. , Meyer G.‐J. , Ruth T. J. , Wolf A. P.
Published: October 2006

m‐Astatobenzoic acid (2) methyl m‐astatobenzoate (3), and m‐astatohippuric acid (4) were synthesized by the melt method. Reaction of methyl m‐bromobenzoate with astatide at 200°C gave methyl m‐astatobenzoate. Compounds 2 and 4 were synthesized by similar method. Compounds 2 and 3 were purified and identified by radio‐gaschromatography.
The synthesis of 13C labelled N, N′‐dimethyl 2‐naphthaleneethanimidamide monohydrochloride, a potential psychotherapeutic agent
Authors: Goralski Christian T. , McCarthy James R. , Linowski J. W. , Nyquist R. A. , Putzig C. L.
Published: October 2006

N, N′ ‐Dimethyl 2‐naphthaleneethanimidamide monohydrochloride (DL‐588) is a potential psychotherapeutic agent for which a sample of carbon‐13 labelled material was required for metabolism studies. The sample of 90% 13C enriched DL‐588 was prepared starting with 90% 13C enriched potassium cyanide in three steps. 2‐(Bromomethyl)naphthalene was treated with the 13C potassium cyanide under phase transfer catalysis. The resulting 13C‐2‐napthylacetonitrile was converted to the imidate ester hydrochloride under Pinner reaction conditions (1). This intermediate was treated with excess methylamine in ethanol at 55° to give the title compound in an overall yield of 68%. The effects of 13C labelling on the 1H NMR spectra of the final product and intermediates are discussed.
A convenient synthesis of [carbonyl‐14C]‐4‐hydroxybenzaldehyde
Authors: Holland Herbert L. , Sultana Nighat
Published: October 2006

A two‐step synthesis of the title compound from [cyano‐14C]‐copper(I) cyanide is described. The method is extensible to the preparation of carbonyl‐labelled 3,4‐dihydroxybenzaldehyde.
Preparation of all trans‐retinoic‐11‐3H acid and all trans‐retinyl‐11‐3H acetate
Authors: Kaegi Hans H. , Degraw Joseph I.
Published: October 2006

Trans‐ionylidineacetaldehyde‐1‐3H (3) was obtained by reduction of unlabeled aldehyde (1) with lithium borotritide, followed by reoxidation of the tritio alcohol (2). Condensation of aldehyde (3) with triethyl 3‐methyl‐4‐phosphonocrotonate (7), followed by saponification of the retinoic ethyl ester (8), afforded trans‐retinoic‐11‐3H acid (9). Esterification of the crystalline acid with diazomethane, and subsequent reduction of the methyl trans‐retinoate‐11‐3H with lithium aluminum hydride, yielded trans‐retinol‐11‐3H, which was acetylated in situ to give trans‐retinyl‐11‐3H acetate (10).
Synthesis of 1‐(3‐trideuteromethoxy‐4‐hydroxyphenyl)‐[1,2,2‐2H3]‐ethyleneglycol ([2H6]MHPG)
Authors: Murray S , Baillie T A , Davies D S
Published: October 2006

The four stage synthesis of a hexadeuterated analogue of the noradrenaline metabolite 3‐methoxy‐4‐hydroxyphenylethylene glycol (MHPG) is described. The overall yield from 3‐trideuteromethoxy‐4‐hydroxyacetophenone is 29%.
Thitium nuclear magnetic resonance spectroscopy. Part 13 [ref. (1)]. Tritium labelled neurochemicals
Authors: Bloxsidge James P. , Elvidge John A. , Gower Marion , Jones John R. , Evans E. Anthony , Kitcher J. Philip , Warrell David C.
Published: October 2006

A series of 50 neurochemicals, important for the investigation of neurotransmission processes, has been labelled with tritium, using in all 8 methods. Tritium nuclear magnetic resonance spectroscopy has been employed to determine the positions and extent of labelling in these neurochemicals which can be important for their use in tracer studies. The specificity of the labelling processes is discussed.
Synthesis, analysis, and stability studies of 14C‐methyl(acetoxymethyl)nitrosamine
Authors: Roller Peter P. , Keefer Larry K. , Iii Wallace W. Bradford , Reist Elmer J.
Published: October 2006

The one‐step synthesis of 14C‐methyl(acetoxymethyl)nitrosamine (14C‐DMN‐OAc) of high specific activity is described. The product was shown to decompose by hydrolysis, as reported previously for the unlabelled material, and by self‐radiolysis, a process which occurred even in methylene chloride solution at high specific activities. Both modes of decomposition led to disappearance of label from the solution, at least partly by sorption to the glass storage vessel. Thin‐layer chromatography proved less suitable for resolving the decomposition products than radio‐gas chromatography. Labelled carbon atoms were found to the extent of only 1% in the formaldehyde produced on esterase hydrolysis of 14C‐DMN‐OAc, showing that scrambling during the synthesis was not extensive. Storage of aqueous solutions for biological work was best accomplished in frozen aqueous solutions of pH 5.5.
Chloramine‐t for “no‐carrier‐added” labelling of aromatic biomolecules with bromine‐75,77
Authors: Petzold G. , Coenen H. H.
Published: October 2006

The applicability of chloramine‐T (CAT) was examined for “no‐carrier‐added” labelling of aromatic compounds with the short‐lived isotopes bromine‐77 (T1/2 = 56 h) and bromine‐75 (T1/2 = 98 min). In aqueous solution the optimum reaction conditions with respect to pH, concentration of CAT, reaction time and added brominecarrier were determined using tyrosine as a model substrate. Highest radiochemical yields (>85%) were obtained at pH 1 within a few seconds at a CAT concentration of 10−3 M. At pH 7 a maximum radiochemical yield of 65% was achieved with 10−2 M after 2.5 minutes. Studies with some model peptides showed that only the tyrosyl residues were brominated and similar yields were obtained as in free tyrosine. Some aromatic molecules such as α‐methyl‐tyrosine, phenylalanine, uracil, cytosine, and phenol were radiobrominated by the CAT method with yields up to 90%. Separation and identification of the labelled products were achieved by means of radio high performance liquid chromatography.
Synthesis of 3H‐lorcainide monohydrochloride (R 15 889)
Authors: Thijssen J. B. A. , Knaeps A. G. , Heykants J. J. P.
Published: October 2006

Lorcainide monohydrochloride, N‐(4‐chlorophenyl)‐N‐/1‐(2‐methylethyl)‐4‐piperidinyl/benzeneacetamide monohydrochioride, is a new orally active antiarrhythmic drug.

Incorporation of tritium was achieved by reduction of 4‐chloro‐N‐/1‐(1‐methylethyl)‐4‐piperidinylidene/benzenamine with tritiated sodium borohydride to N‐(4‐chlorophenyl‐1‐1‐methylethyl)‐4‐piperidinamine. This compound was converted in situ into the amide derivative.

The radioactive yield of the last two synthesis steps was 82.7 % spread over two fractions with specific activities of 1.1 Ci/mmol and 0.046 Ci/mmol. The labelled compounds were radiochemically pure according to thin‐layer chromatography in three solvent systems, and high‐performance liquid chromatography. The radiochemical stability of lorcainide monohydrochloride investigated in both acidic and alkaline media for 1 hour at 60°C was found to be excellent.
14C‐markierte kohlenwasserstoffe durch katalytische isomerisierung
Authors: Dermietzel Jürgen , Jockisch Wolfgang , Räuber Günther
Published: October 2006

A general procedure for the synthesis of labelled hydrocarbons by catalytic isomerization in a microreactor is described.

At four studied reactions (synthesis of isohexanes, methylcyclopentane, methylcyclopentenes and xylenes) the thermodynamically expected equilibrium concentrations could be approached. For product separation a direct coupling of the microreactor with a prep‐scale gaschromatographic unit is favorable.
Bledta II: Synthesis of a new tumor‐visualizing derivative of CO(III)‐bleomycin
Authors: Deriemer Leslie H. , Meares Claude F. , Goodwin David A. , Diamanti Carol I.
Published: October 2006

A new bifunctional chelating agent, (S)‐l‐(p‐bromoacetamidobenzyl) ethylenedinitrilotetraacetic acid, has been prepared from L‐phenylalanine. Reaction of the chelating agent with the Co(III) complex of the antitumor antibiotic bleomycin‐A2DM was used to generate a new derivative of Co(III)‐bleomycin, BLEDTA II. The product can be radiolabeled quickly by binding a radioactive metal ion to the EDTA group. The in vivo distribution of 111 In‐BLEDTA II in tumor‐bearing mice was determined and found to be indistinguishable from that of the clinically useful 111 In(III)‐BLEDTA I complex (J. Med. Chem. 22: 1019 (1979)).
Synthesis of 3H‐labelled indicine N‐oxide
Authors: Piper James R. , Kari Prasad , Shealy Y. Fulmer
Published: October 2006

Indicine N‐oxide, an antitumor agent possessing an unusual type of potential alkylating capacity, was recently selected for clinical trial. Radioactive‐labelled indicine N‐oxide was sought for studies of its biological properties relating to antitumor activity and toxicity. Available indicine N‐oxide was reduced to indicine, and the alkaloid ester was hydrolyzed to its component compounds, retronecine and (−)‐trachelanthic acid. The radioactive label was then introduced into the hydroxymethyl grouping of retronecine by a previously reported procedure involving oxidation of retronecine to methyl 1,2‐dehydro‐7β‐hydroxy‐8α‐pyrrolizidine‐1‐carboxylate followed by reduction of the methoxycarbonyl grouping with LiAl3H4. Recombination of the alcohol and the carboxylic acid, a heretofore challenging problem in syntheses of pyrrolizidine alkaloid esters, was achieved using an adaptation of the mild esterification procedure recently reported by Hassner and Alexanian. By this method, indicine was obtained following reaction of retronecine, the isopropylidene derivative of (−)‐trachelanthic acid, and N,N′‐dicyclohexylcarbodiimide in the presence of 4‐(dimethylamino)pyridine in toluene. Tritium‐labelled indicine thus formed was then treated with m‐chloroperoxybenzoic acid to give labelled indicine N‐oxide.
Deuterium exchange labelling of biologically important phenols, indoles and steroids
Authors: Vining R. F. , Smythe G. A. , Long M. A.
Published: October 2006

Deuterated analogues of various phenolic steroids, catechols and indole derivatives were prepared in high chemical yield by heating the relevant compound in D2O at 190°C for 24 hours.
Synthesis of 14C‐labelled 1‐(4‐chlorobenzyl)‐3‐methyl‐3‐(2‐hydroxyethyl)‐thiourea
Authors: Esses‐Reiter K. , Reiter J.
Published: October 2006

1‐(4‐Chlorobenzyl)‐3‐methyl‐3‐(2‐hydroxyethyl)‐thiourea labelled with 14C at its urea group was synthesised starting from potassium cyanide‐14C, via potassium thiocyanate‐14C, 4‐chlorobenzyl‐thiocyanate‐14C and 4‐chlorobenzyl‐isothiocyanate‐14C. The conditions of the isomerisation of 4‐chlorobenzyl‐thiocyanate‐14C to 4‐chlorobenzyl‐isothiocyanate‐14C were studied in detail.
Enzymatic labelling of carcinoembryonic antigen with iodine‐125
Authors: Siuda Andrzej , Lucka Barbara , Russin Krystyna
Published: October 2006

Carcinoembryonic antigen /CEA/ was labelled with iodine‐125 using lactoperoxidase. The radiochemical yield of /125I/CEA was about 25% at the specific activity of about 30μCi/μg /1.1MBq/μg/. The percentage binding of /125I/CEA with specific anti‐CEA serum was determined in lyophilized samples during storage. The obtained /125I/CEA preparations can be utilized in radioimmunoassay kits for at least two months.
Synthesis of clomipramine‐d8
Authors: Chaudhuri Naba K. , Sung Ming‐Sang , Markus Bohdan
Published: October 2006

The synthesis of deuterium labelled clomipramine which is an antidepressant drug is described. Eight deuterium atoms have been incorporated specifically into the nonaromatic part of the molecule — six atoms at 1, 2, and 3 positions of the dimethyl‐ aminopropyl side chain and two atoms at the 10 and 11 positions of the molecule. 1,1,2,2,3,3‐Hexadeutero‐3‐dimethylaminopropyl chloride has been synthesized for this purpose and used for the construction of the labelled side chain.
Synthesis of 1‐[2‐hydroxy‐4‐(3‐sulfo‐1‐propyloxy)‐phenyl]‐ ‐3‐(3‐hydroxy‐4‐methoxyphenyl)‐propan‐1‐one‐1‐14C sodium salt
Authors: Koltai E. , Esses‐Reiter K. , Bánfi D.
Published: October 2006

1‐[2‐hydroxy‐4‐(3‐sulfo‐1‐propyloxy)‐phenyl]‐3‐ ‐(3‐hydroxy‐4‐methoxyphenyl)‐propan‐1‐one sodium salt labelled with 14C at its carbonyl group (1) was synthetized starting from sodium acetate‐1‐14C through acetyl chloride‐1‐14C, resacetophenone‐carbonyl‐14C (2), 2‐hydroxy‐4‐(3‐sulfo‐1‐propyloxy)‐acetophenone‐carbonyl‐14C sodium salt (3) and 1‐[2‐hydroxy‐4‐(3‐sulfo‐1‐propyloxy)‐phenyl]‐3(3‐hydroxy‐4‐methoxyphenyl)‐2‐ propen‐1‐one‐1‐14C (4).
Synthesis of 14C‐labelled crotamiton
Authors: Chaudhuri Naba K. , Potdar Sudhakar V. , Ball Thomas J.
Published: October 2006

The synthesis of 14C‐labelled crotamiton, which is a fungicide, an insecticide as well as a scabicide is described. Starting from 2‐bromonitrobenzene and Cu14CN, o‐toluidine, labelled with 14C at the methyl group was prepared by the following sequence of reactions: NO2‐C6H4‐Br → NO2‐C6H4‐14CN → NO2‐C6H4‐14COOH → NO2‐C6H4‐14CH2OH → NO2‐C6H4‐14CH2Br → NH2‐C6H4‐14CH3. Labelled o‐toluidine was then heated with crotonic anhydride to give crotonic acid o‐toluidide which was then ethylated by treatment with sodium hydride and ethyl iodide to obtain labelled crotamiton.
Tritium‐labelling of lipids
Authors: Shevchenko V. P. , Myasoedov N. F.
Published: October 2006

Tritium‐labelled lipid preparations are obtained by heterogeneous isotopic exchange with gaseous tritium in solution. After appropriate purification, the localization of the label was determined in the main fragments of [3H]‐compounds. The obtained data on specific radioactivity and the pattern of label localization allow an insight into processes taking place on labelling under particular experimental conditions.
Synthesis of O,S‐diethyl 2‐(bromomethyl‐13C)‐2‐methylthiomalonate, a model substrate for methylmalonyl‐co a mutase reactions
Authors: Chung S. K. , Hansen J. B.
Published: October 2006

O,S‐Diethyl methylthiomalonate was efficiently condensed with paraformaldehyde‐13C in the presence of sodium methoxide to give 2‐[13C]‐hydroxymethylated product, which was converted to 2‐[13C]‐bromomethyl product by treatment with triphenylphosphine and carbon tetrabromide.
Synthese du phosphate d'isopropylamino‐2 pyrimidine (14C2‐4,6) a tres forte activite specifique
Authors: Pabiot J. M. , Pichat L. , Cen‐Saclay  , Esanu A. , Pommier J. , Laurent J. P.
Published: October 2006

Syntnesis of very high specific activity (4,6‐14C2) 2‐isopropylaminopyrimidine phosphate (I.A.P.P.)

(1‐14C) Sodium acetate (specific activity : 57 mCi/mMole)‐ was transformed into ethyl (1‐ C) acetate with a 76 % yield. The latter was lithiated with lithiodiisopropylamide. The intermediate ethyl (1‐14C) lithioacetate was carbonated with 14CO2 (specific activity : 57 mCi/mMole) to give monoethyl (1,3‐14C2) malonate which was esterified into diethyl (1,3‐14C2) malonate. The latter was condensed with N‐isopropylguanidne to give 4,6‐dihydroxy 2‐iso‐propylamino (4,6‐14C2) pyrimidine. Treatment with POBr3 gave 4,6‐dibromo 2‐isopropylamino (4,6‐14C2) pyrimidine the hydrogenation of which under controlled conditions gave 2‐isopropylamino (4,6‐14C2) pyrimidine isolated as the phosphate. Specific activity was 114 mCi/mMole, radiochemical purity (TLC and HPLC) was 99 % ‐ overall yield was 7 % based on (14 C) carbon dioxide.
Tritium labelled compounds of high specific activity II. amitriptyline
Authors: Zólyomi G. , Sirokmán F. , Tóth G. , Elekes I.
Published: October 2006

Tritium labelled amitriptyline (1) of high specific activity was prepared. The tritium was incorporated by catalysed isotope exchange into the precursor dibenzosuberone, which had been previously converted into a cyclic ketal, in order to protect the oxo‐group against reduction. It was demonstrated by degradation that isotope exchange occurred exclusively in specified position.
The synthesis of tritiated methoxamine with high specific activity
Authors: Demarinis R. M. , Villani A. J. , Brungard D. , Meier J.
Published: October 2006

Tritiated methoxamine with a specific activity of 28.5 Ci/mmol was prepared by iodination of methoxamine followed by catalytic tritiation.
Synthesis and quality control of 125I‐and 14C‐labelled 5‐iodo‐2′‐deoxycytidine triphosphate
Authors: Linz Ute
Published: October 2006

A method is described for a no‐carrier‐added synthesis and purification of doubly‐labelled [5‐125I, U‐14C]‐iododeoxycytidine triphosphate. Iodination of 14C‐dCTP was achieved with a radiochemical yield of 80%. Separation and purification of the reaction product were accomplished by reversed‐phase high performance liquid chromatography (RP‐HPLC).
Enzymatic synthesis of radio‐labeled selenocystine from labeled serine and selenide
Authors: Dilworth Gregory L.
Published: October 2006

Selenocysteine can be formed enzymically from O‐acetylserine and sodium selenide by O‐acetylserine sulfhydrylase. The preparation of O‐acetylserine from serine and its conversion to selenocystine are described. These reactions can be used to synthesize [14C], [3H], or [75Se]selenocystine.
Preparation of deuterium and tritium labelled norethynodrel, norethindrone, and 6‐methyleneandrostenedione
Authors: Holland Herbert L. , Brown Frances M. , Tan Liat
Published: October 2006

A convenient, one step method for the preparation of deuterium or tritium labelled norethynodrel, norethindrone, and 6‐methyleneandrostenedione is reported which utilizes water as the source of label. The choice of exchange reagent (lithium or sodium hydroxide) is crucial in controlling rearrangement of the chemically labile β, γ unsaturated carbonyl function of norethynodrel.
124Sn‐labelled tetra‐n‐butyltin and tri‐n‐butyltin bromide
Authors: Testa J. P. , Dooley C. A.
Published: October 2006

Stable isotope‐labelled tetra‐n‐butyl (124) tin was synthesized by the reaction of n‐butylmagnesium bromide with 124SnCl4. Tri‐n‐butyltin bromide was synthesized by bromine cleavage of the tetraalkyltin. The compound can be used to trace chemical, biological and physical processes in environmental and metabolic studies using gas chromatography and electron impact low resolution mass spectrometry. The simplified spectra of the isotopically enriched compounds leads to a twofold increase in detection sensitivity by GC/MS.
Total synthesis of [7‐14C]‐(±)‐colchicine
Authors: Pontikis Renée , Nam Nguyen Hoang , Hoellinger Henri
Published: October 2006

The synthesis of (±)‐colchicine 1 labelled with carbon‐14 at the 7‐position of the B ring was achieved by a sixteen step sequence with an overall radiochemical yield of 2.5% from [Ba14CO3] (Specific activity : 55 mCi‐mmol−1).
Tritium‐labelling of natural and modified prostaglandins
Authors: Shevchenko V. P. , Bezuglov V. V. , Nagayev I. Yu. , Myasoyedov N. F.
Published: October 2006

The paper describes the synthesis of [5,6‐3H2]PGE1, 15‐fluoro‐15‐deoxy‐[5,6‐3H2]PGE1 and 11‐deoxy‐[5,6,10,11‐3H4]PGE1 through selective hydrogenation in the presence of heterogeneous and homogeneous catalysts. With heterogeneous catalysts, the yield of labelled compounds was 35%. If bulk substituents were introduced and (Ph3P)3RhCl was used as the catalyst, the yield of labelled prostaglandins was increased to 70%.
A one‐pot radiosynthesis of [125I]iodoazido photoaffinity labels
Authors: Wilson Alan A. , Grigoriadis Dimitri E. , Dannals Robert F. , Ravert Hayden T. , Wagner Henry N.
Published: October 2006

A useful method for preparing radioiodinated photoaffinity labels from alkyl anilines which offers significant advantages over present methods is described. The one‐pot synthesis gives good radiochemical yields (40–64%) of pure, high specific activity (350–1500 mCi/μmol) 125I labelled iodoaryl azides while minimising manipulation of radioactive materials. Purification of the [125I]iodoazido photoaffinity labels is achieved by high performance liquid chromatography.
Synthesis and preliminary evaluation of L‐6‐[123I]Iododopa as a potential spect brain imaging agent
Authors: Adam Michael J. , Ponce Yolanda Zea , Berry Joffre M. , Hoy Kevin
Published: October 2006

L‐6‐[123I]Iododopa was synthesized by the exchange of 123I for bromine on L‐6‐bromodopa in buffer(pH 4) for 35 minutes at 97°C. The synthesis was complete in approximately 1 hour with a radiochemical yield of 50%, a specific activity of 65 Ci/mmol and a radiochemical purity of ≥95%. A non radioactive standard of L‐6‐iododopa was synthesized by the iododemercuration of a mercury‐dopa derivative using I2 in chloroform. It was shown that L‐6‐[123I]iododopa accumulated in the rat striatum with striatum:whole brain ratio of 1.36 at 1 hour and 1.11 at 2 hours.
Synthesis of [195mPt]‐tetraplatin
Authors: Wyrick Steven D. , Chaney Stephen G.
Published: October 2006

(Trans d,1)‐1,2‐diaminocyclohexanetetrachloroplatinum(IV) (tetraplatin) is a second generation platinum antitumor agent which exhibits less toxicity than cisplatin and is effective in cell lines with acquired resistance to cisplatin. We previously reported the synthesis of tritium labelled tetraplatin which was utilized in both tissue culture and in vivo studies. Loss of the labelled diaminocyclohexane carrier moiety during the in vivo studies necessitated the synthesis of [195mPt]‐tetraplatin from [195mPt]‐potassium hexachloroplatinate as described herein.
Synthesis and enantiomeric resolution of tritiated (D,L)‐3‐hydroxykynurenine
Authors: Lever John R. , Canella Karen A. , Eastman Clifford L. , Guilarte Tomas R.
Published: October 2006

The synthesis, purification and enantiomeric resolution of tritiated (D,L)‐3‐hydroxykynurenine are described. Bromination of racemic 3‐hydroxykynurenine, catalytic dehalotritiation and purification by ion pair, reverse phase HPLC afforded tritiated material of high radiochemical purity (99.8%) and moderate specific radioactivity (3.64 Ci/mmol). Enantiomerically pure (D)‐ and (L)‐stereoisomers were isolated using chiral HPLC conditions. The stability of the label toward isotopic exchange was assessed to be sufficient for biochemical studies.
Synthesis of [14C]A‐62514, a radiolabelled derivative of erythromycin a, via [2‐14C]N, N‐dimethylethylenediamine
Authors: Surber Bruce W. , Baker William R. , Seif Louis
Published: October 2006

The synthesis of [14C]A‐62514, 11‐deoxy‐11‐[carboxy(2‐dimethylamino‐[1‐14C]ethyl)amino]‐6‐0‐methyl‐erythromycin A 11,12‐(cyclic ester), was performed in five steps. The key intermediate, [2‐14C]N, N‐dimethylethyl‐enediamine, was obtained in 80% yield by reacting Eschenmoser's salt with K14CN and reducing the resulting [1‐14C]N, N‐dimethylglycinonitrile with H12 and Raney Ni in methanol and ammonium hydroxide. The final product was obtained 97% radiochemically pure in an overall radiochemical yield of 14%, with a specific activity of 39 mCi/mmol.
Synthesis and evaluation of [3H]‐4‐fluoro‐1‐[1‐(3‐hydroxyphenyl)cyclohexyl]piperidine, a potential tool for autoradiographic study of the phencyclidine receptor
Authors: de Costa Brian R. , Mattson Mariena V.
Published: October 2006

The synthesis and in vitro binding of high specific activity tritium labelled 4‐fluoro‐1‐[1‐(3‐hydroxyphenyl)cyclohexyl] piperidine ([3H]FOH‐PCP), a potential probe for autoradiographic study of the phencyclidine (PCP) receptor is described. [3H]FOH‐PCP will allow evaluation of [18F]FOH‐PCP as a PET scanning ligand for PCP receptors.
Synthesis of tritiated 1‐[2‐(diphenylmethoxy)ethyl]‐4‐[3‐(3‐azidophenyl)propyl]piperazine ([3H]‐meta azido GBR‐12935), a photoaffinity ligand for the dopamine reuptake site
Authors: Thurkauf A. , de Costa B. , Berger P. , Paul S. , Rice K. C.
Published: October 2006

A tritiated photoaffinity ligand for the dopamine reuptake transporter protein, 1‐[2‐(diphenylmethoxy) ethyl]‐4‐[3‐(3‐azidophenyl)‐2,3‐ditritiopropyl]piperazine, of specific activity 41.8 Ci/mmol, was prepared in six steps starting from 1‐[2‐(diphenylmethoxy)ethyl] piperazine.
Synthesis of high specific activity (3,4‐[3H]cyclohexyl)‐N‐[1 (2‐benzo[b]thienyl)cyclohexyl]piperidine {[3H]BTCP}: A selective probe for the dopamine‐reuptake complex
Authors: de Costa Brian R.
Published: October 2006

High specific activity [3H]BTCP, a radioligand for the dopaminereuptake complex was synthesized in 7‐steps starting with the readily available starting materials, cyclohexane‐1,4‐dione monoethylene ketal and benzo[b]thiophene; the tritium label was introduced in the final step on the 3‐ and 4‐ positions of the cyclohexyl ring by catalytic tritiation of N‐[4‐(2‐benzo[b]thienyl)cyclohexenyl]piperidine to give [3H]BTCP in 7.3% yield with a specific activity of 29.8 Ci/mmol (51.4% isotopic incorporation).
Synthesis of (±)‐trans‐6‐[4,4‐bis(4‐fluorophenyl)‐3‐ (1‐methyl‐1H‐tetrazol‐5‐YL)‐1(E),3‐[2‐14C] butadienyl]‐4‐hydroxy‐3,4,5,6‐tetrahydro‐2H‐pyran‐2‐one
Authors: Luke G. M. , Swigor J. E.
Published: October 2006

A convergent synthesis of the title compound (BMY‐22089) is described. [14C]Methyl iodide was used to alkylate 1,5‐dimethyltetrazole which was added to 4,4′‐difluorobenzophenone to give the tertiary alcohol 4. Dehydration gave, the olefin 5 which was brominated and converted to the phosphonate 7 with trimethylphosphite. Coupling of the carbanion of 7 with cis‐2,2‐dimethyl‐6‐formyl‐1,3‐dioxane‐4‐acetic acid tert‐butyl ester (8) produced the diene 9. Sequential hydrolysis steps using acid and base gave the dihydroxy acid 11 which was converted to the lactone 12 with the use of dicyclohexylcarbodiimide. The overall yield was 20%.
Stereoselective synthesis of L‐[4‐13C]carnitine
Authors: Unkefer Clifford J. , Ehler Deborah S.
Published: October 2006

The stereoselective synthesis of L‐[4‐13C]carnitine was achieved in 5 steps. The label was introduced from K13CN into an easily separated diastereomeric pair of 3‐deoxy‐D‐[1‐13C]aldohexoses. Reductive amination of the labeled aldohexose yielded the corresponding D‐1‐(dimethylamino)[1‐13C]alditol which was oxidized in two steps and alkylated with iodomethane to yield L‐[4‐13C]carnitine. The stereochemical integrity at C‐2 of the 3‐deoxy‐D‐[1‐13C]glucose precursor was maintained throughout the synthesis of L‐[4‐13C]carnitine.
Tritium incorporation in α‐amino acids by isotope exchange using high‐temperature solid‐state catalysis
Authors: Zolotarev Yu. A. , Kozic V. S. , Zaitsev D. A. , Dorokhova E. M. , Myasoedov N. F.
Published: October 2006

Solid‐state catalytic reactions provide a new effective method for the synthesis of tritium‐labelled biologically active compounds. We present the synthesis of tritium‐labelled amino acids through high‐temperature solid‐state catalytic isotope exchange (HSCIE). Under HSCIE, isotope exchange with gaseous tritium was shown to proceed at all hydrogen atoms in the molecules of solid organic compounds, which opens the possibility of producing biologically active compounds uniformly labelled with tritium at high molar activity. The configuration is retained upon the hydrogen atom substitution at asymmetrical carbon atoms under BSCIE conditions, allowing the synthesis of uniformly‐labelled amino acids in the optically active form.
The effect of iodine position on uptake in the mouse using an isomeric series of 2‐deoxy‐2‐O‐([123I]‐iodobenzyl)glucoses
Authors: Lutz T. , Dougan H. , Rihela T. , Hudon M. , Cohen P. , Jamieson W. R. E. , Lyster D. M.
Published: October 2006

The ortho, meta and para iodinated series of 2‐deoxy‐2‐O‐(iodobenzyl)glucose (IBG) were prepared by addition of the desired iodobenzyl bromide with 3,4,6‐tri‐O‐acetyl‐piperidine‐N‐D‐glucose. Subsequent exchange labelling with [123I]NaI enabled their biodistribution to be studied in mice. The lipophilicity of each compound was measured by their octanol:water partition coefficients, showing the meta‐ and para‐IBG to be more lipophilic than ortho‐IBG. Examination of the biodistribution data suggests that there is a correlation between tissue uptake and iodine position(lipophilicity).
Synthesis of carbon‐11 labelled (R)‐carnitine
Authors: Holschbach M. , Hamkens W. , Roden W. , Feinendegen L. E.
Published: October 2006

A route to 11C‐labelled (R)‐carnitine (1), based on the methylation of the dimethyl derivative (2) is described. Furthermore, a five‐step synthesis for the enantiomerically pure precursor (2) is outlined.
Syntheses de Methylpyridines Deuteriees
Authors: Lautie Marie‐France , Leygue Nadine
Published: October 2006

Picolines and 2,6‐lutidines partially deuterated on the methyl group or fully deuterated have been prepared with high isotopic purity. Monodeuteration of the methyl group was obtained either by deuterolysis of lithiated derivatives or by reduction of CH2X group with Bu3SnD. Dideuteriomethyl compounds were synthesized by reduction of the corresponding esters with LiAlD4 and conversion of the alcohol to chloromethyl derivatives which were finally reduced by an acetic acid‐zinc mixture. Exchanges with heavy water on platinum yield γ‐picoline‐D7 and 2,6‐lutidine‐D9.
A concise synthesis of [carbonyl‐11C]melatonin and N‐[carbonyl‐ 11C]acetylserotonin
Authors: Tada Masao , Oikawa Atsushi , Iwata Ren , Sato Kazunori , Sugiyama Hiroshi , Takahashi Hiromu , Wakui Akira , Fukuda Hiroshi , Kubota Kazuo , Abe Yoshinao , Yamaguchi Tatsuo , Fujiwara Takehiko , Sato Tachio , Ido Tatsuo
Published: October 2006

Rapid chemical syntheses of [carbonyl‐ 11C]melatonin and N‐[carbonyl‐ 11C]acetylserotonin starting from [11C]carbon dioxide are described. The radiochemical yield (based on [carbonyl‐11C]‐acetic acid), purity, and the specific activity (end of bombardment) of the former are 12%, >98%, and 4.2 Ci/μmol, respectively. The latter is also synthesized with the same radiochemical yield, purity, and specific activity. The total times required for their syntheses are ca. 45 min, respectively.
The investigation of solid‐state catalytic hydrogenation of organic compounds. II. The synthesis of tritium‐labelled valine
Authors: Zolotarev Yu. A. , Kozik V. S. , Dorokhova E. M. , Myasoedov N. F. , Rozenberg S. G.
Published: October 2006

We report here the investigation of solid‐state catalytic hydrogenation (SCH) of unsaturated compounds, used for the synthesis of tritium labelled valine The effect of the solidstate components ratio, tritium pressure and reaction temperature on the reaction rate has been investigated. It has been found that the SCH reaction rate depends linearly on tritium pressure in the 5–50 kPa interval. 3H NMR spectroscopy was used to determine the distribution of tritium label in synthesized valine. It was found, that the distribution of tritium label in the product molecules depends both on the precursor compound structure and the reaction temperature. SCH activation energy was determined to be equal to 11 kcal/mol. The application of solid‐state isotope exchange for tritium labelling of unsaturated compounds has been shown for 3,3‐dimethyl‐2‐benzoylaminoacrylic acid.
Synthesis of 5‐[125I]‐iodo‐zacopride, a new probe for 5‐HT3 receptor binding sites
Authors: Ponchant M. , Koscielniak T. , Hamon M. , Gozlan H.
Published: October 2006

In an attempt to develop a specific probe of serotonin 5‐HT3 receptors, various methods have been investigated to synthesize a radioiodinated derivative of the potent 5‐HT3 antagonist zacopride. The direct iodination of 5‐dechloro‐zacopride 2 was performed using NaI in the presence of either chloramine T or iodo‐beads. Irreproducible results or/and low yields were obtained by these methods. A third approach using a less oxidative medium allowed the synthesis of iodo‐zacopride 4 from 2 with N‐iodo‐succinimide or with NaI and N‐chlorosuccinimide. Using this third condition, high yield was obtained (49%). However, the radioiodinated compound was contaminated by some “cold” zacopride also formed during the reaction. A two step synthesis was successful to eliminate “cold” zacopride but in lower yield (2‐10%). Thus, 4‐amino‐2‐methoxy‐benzoate 5 was iodinated and then coupled with 3‐aminoquinuclidine 8 to give 5‐iodo‐zacopride 4. Radioactive synthesis was carried out in the same condition to give 5‐[1251]‐iodo‐zacopride 1 with a yield of 98%. The two enantiomers R‐and S‐5‐[1251]‐iodo‐zacopride were synthesized by direct iodination.
Synthesis Of N,N‐dimethyl‐[β‐(3,4‐diacetoxy‐6‐123I‐iodophenyl)]‐ethylamine (IDDE): A potential radiotracer for the study of the dopaminergic system
Authors: Adam Michael J. , Ponce Yolanda Zea , Berry Joffre M. , Lu Jianming
Published: October 2006

N.N‐Dimethyl‐[β‐(3,4‐Diacetoxy‐6‐123I‐Iodophenyl)]ethylamine (IDDE) was synthesized by the iododemercuration reaction with [123I]‐NaI and Chloramine‐T. The iodinated compound was deprotected with BBr3, acetylated and purified by HPLC to give the final product in 43% radiochemical yield. The radiochemical purity was >97%.
Synthesis of (R, R)123I‐QNB, A spect imaging agent for cerebral muscarinic acetylcholine receptors in vivo
Authors: Owens J. , Murray T. , McCulloch J. , Wyper D.
Published: October 2006

The high‐affinity muscarinic receptor antagonist (R,R) I‐QNB(1) [(R)‐(‐)‐1‐Azabicyclo [2.2.2]oct‐3‐yl‐ (R) ‐ (+) ‐ α‐hydroxy‐α‐(4‐[127I]iodophenyl)‐α‐phenyl Acetate (6a)] has been labeled with iodine‐123 to give a suitable ligand for SPECT (Single photon emission computed tomography) imaging of the human brain. The radiolabeling is achieved using a copper(I) assisted nucleophilic exchange mechanism(2) to give high specific activity (R,R)123I‐QNB in reasonable overall yield (36%). The radiolabeling reaction is carried out in the presence of excess reducing agent and the product (R,R)123I‐QNB purified on a Sep‐Pak cartridge eliminating the need for h.p.l.c. purification the synthesis of the precursor (127I‐QNB) for the radiolabeling step is a modification of the procedure reported by Rzeszotarski et. al(3) (R)‐α‐Hydroxy‐α‐(4‐nitrophenyl)‐α‐phenylacetic acid was produced from 4‐nitrobenzophenone and resolved as reported. The methyl ester of the acid was synthesised then the nitro group converted to an amino group to give Methyl, (R) ‐α‐hydroxy‐α‐ (4‐aminophenyl) ‐a‐ phenyl acetate. The iodo compound Methyl, (R) ‐α‐hydroxy‐α‐ (4‐iodophenyl)‐α‐phenyl acetate was produced from the amino compound via the diazonium salt. Transesterification of the iodo compound with (R) ‐3‐quinuclidinof gave (R, R) ‐f271‐QNB.

The (R,R) 123I‐QNB produced has been successfully used to image muscarinic receptors in patients suffering from Alzheimers disease.
Synthesis of [19‐3H] herbimycin A
Authors: Dow Robert L. , Bechle Bruce M. , Chalabi Phillip M. , Windels James H. , Roth Robert W.
Published: October 2006

Herbimycin A, an ansamycin antibiotic, is known to reverse the transformed phenotype of cells transfected with tyrosine kinase expressing oncogenes. The synthesis of [19‐3H] herbimycin A (1c), a potential tool for unraveling the mechanism of this reversal, is described. Reduction of 19‐bromoherbimycin A (4) employing zinc‐copper couple/tritiated water affords hydroquinone (5c) which, when treated with manganese dioxide, affords 1c.
(N‐[11C]‐Methyl)doxepin: Synthesis of a radiotracer for studying the histamine H‐1 receptor
Authors: Ravert Hayden T. , Dannals Robert F. , Wilson Alan A. , Wagner Henry N.
Published: October 2006

Doxepin (3‐dibenz [b,e] oxepin ‐ 11(6H) ‐ ylidene ‐ N,N ‐ dimethyl ‐ 1 ‐ propanamine), a potent H1 histamine antagonist, was labeled with 11C‐iodomethane by N‐alkylation of normethyldoxepin. The synthesis, purification, and formulation were performed in approximately 20 minutes with an average specific activity of 1630 mCi/μmol (EOS).
Synthesis of Carbon‐14 labeled gadoteridol, [1,4,7‐Tris(carboxymethyl)‐10‐(2‐hydroxy‐1‐[14C]propyl)‐1,4,7,10‐tetraazacyclododecanato]gadolinium
Authors: Dischino D. D. , Swigor J. E.
Published: October 2006

Carbon‐14 labeled Gadoteridol, [1,4,7‐Tris(carboxymethyl)‐10‐(2‐hydroxy‐1‐[14C]propyl)‐1,4,7,10‐tetraazacyclododecanato]gadolinium, was prepared from 1‐[14C] propylene oxide in a total yield of 30.4% and a radiochemical purity of 99.2%.
Synthesis of 17α‐[125I]iodoethynyl‐4,6‐androstadien‐17β‐OL‐3‐ONE, an active‐site‐directed photoaffinity radiolabel for androgen‐binding proteins
Authors: Mason N. Scott , Smith Howard E. , Danzo Benjamin J. , Clanton Jeffrey A.
Published: October 2006

17α‐[125I]Iodoethynyl‐4,6‐androstadien‐17β‐ol‐3‐one with a specific radioactivity of 24 Ci/mmol was prepared as an active‐site‐directed photoaffinity radiolabel for androgen‐binding proteins. The iodinated steroid was formed by the silver nitrate‐catalyzed reaction of N‐[125I]iodosuccinimide and 17α‐ethynyl‐4,6‐androstadien‐17β‐ol‐3‐one in acetone. N‐[125I]Iodosuccinimide was prepared by reaction of silver succinimide with iodine‐125 in dioxane, the latter being formed by oxidation of sodium iodide‐125 with sodium nitrite‐nitric acid in water‐hexane.
Synthesis of racemic [α‐11C]amphetamine and [α‐11C]phenethylamine from [11C]nitroalkanes
Authors: Schoeps Karl‐Olof , Halldin Christer
Published: October 2006

The synthesis of racemic [α‐11C]amphetamine and [α‐11C]‐phenethylamine from on‐line produced [11C]nitroethane and [11C]nitromethane, respectively, is described. The condensations of nocarrier‐added [11C]nitroalkanes with benzaldehyde to form [β‐11C]β‐nitrostyrenes were investigated under basic and acidic conditions. The [β‐11C]β‐nitrostyrenes were reduced with lithium aluminium hydride to produce the corresponding saturated amines. Purification was performed with semi‐preparative reversed‐phase HPLC using a Suplex pKb‐100 column. The total radiochemical yields were 7‐20% (from EOB and decaycorrected) and 24‐35% (based on [11C]nitroalkanes and decay‐corrected) with a total synthesis time of 40‐55 min. The specific radioactivity of [α‐11C]amphetamine and [α‐11C]phenethylamine at EOS was 200‐1000 Ci/mmol (7.4‐37 GBq/μmol) with a radiochemical purity >99%.
Synthesis of (R)‐5‐(Di[2,3‐3H2]propylamino)5,6‐dihydro‐4H‐imidazo[4,5,1‐ij]quinolin‐2(1H)‐one ([3H]U‐86170) and (R)‐5‐([2,3‐3H2]Propylamino)‐5,6‐dihydro‐4H‐imidazo[4,5,1‐ij]quinolin‐2(1H)‐one ([3H]U‐91356)
Authors: Moon Malcolm W. , Hsi Richard S. P.
Published: October 2006

(R)‐5‐(diallylamino)‐5,6‐dihydro‐4H‐imidazo[4,5,1‐ij]quinolin‐2(1H)‐one (12b) was prepared in 9% overall yield from 3‐aminoquinoline. Reaction of 12b in ethyl acetate with tritium gas in presence of a 5% platinum on carbon catalyst afforded a mixture of (R)‐5‐(di[2,3‐3H2]propylamino)‐5,6‐dihydro‐4H‐imidazo[4,5,1‐ij]‐quinolin‐2(1H)‐one ([3H]U‐86170, 13, 69 Ci/mmol) and (R)‐5‐([2,3‐3H2]‐propyl‐amino)‐5,6‐dihydro‐4H‐imidazo‐[4,5,1‐ij]quinolin‐2(1H)‐one ([3H]U‐91356, 14, 34 Ci/mmol) which was separated by preparative reverse‐phase chromatography. U‐86170 and U‐91356 are potent dopamine D2 agonists. The labelled compounds are useful for drug disposition studies. [3H]U‐86170 is also useful as a dopamine D2 agonist radioligand for receptor binding studies.
The synthesis of [14C] labelled Eutypine
Authors: Defrancq Eric , Tabacchi Raffaele
Published: October 2006

The synthesis of radiolabelled 4‐hydroxy‐3‐(3‐methyl‐3‐buten‐1‐ynyl) benzaldehyde (eutypine 1), a phytotoxic compound isolated from the culture media of the fungus Eutypa lata, responsible for vineyard die‐back, is described. The radioisotope 14C was introduced via a Wittig reaction using [14C] methyl‐iodide as precursor.