bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and biodistribution of radioiodinated selenonium salts: Potential myocardial imaging agents
Authors: Parikh A. S. , Basmadjian G. P. , Gilliland D. L. , Greenwood R. B. , Rieger J. A. , Weaver A.
Published: October 2006

(o‐[125I]iodobenzyl)benzylmethylselenonium tetrafluoroborate (1) and (o‐[125I]iodobenzyl)dibenzylselenonium tetrafluoroborate (2) were synthesized by methylation and benzylation of o‐[125I]iodobenzyl benzyl selenide respectively. The starting compound o‐iodobenzyl benzyl selenide was radioiodinated with sodium [125I]iodide by melt‐exchange in a sealed ampoule maintained at 75°C for 12 hours, with subsequent chromatographic purification yielding the pure compound in a radiochemical yield of 33.0% and specific activity of at least 68.0 mCi/mmol. Tissue distribution studies of compounds 1 and 2, performed in rats, showed that the labelled compounds accumulated rapidly in the heart. The maximum heart‐to‐blood ratios for compounds 1 and 2 were 4.2:1 and 4.4:1 compared to that of 2.0:1 for previously synthesized [75Se]Trimethylselenonium Iodide (3).
Catalytic dehalogenation of N‐acetyl‐L‐4‐chloro‐ and N‐acetyl‐L‐4‐iodophebylalanine amide in the presence of deuterium
Authors: Oehlke J. , Bienert M. , Niedrich H. , Zöpfl H.‐J. , Franke P.
Published: October 2006

As a model for the tritium labeling of peptides, the catalytic dehalogenation of N‐Acetyl‐L‐4‐chloro‐ and N‐Acetyl‐L‐4‐iodo‐phenylalanine amide was investigated in the presence of deuterium, using different reaction conditions. A catalyst‐mediated transfer of the solvent‐hydrogen to the substrate was found to be the most probable reason for the exchange of halogen by hydrogen instead of deuterium. This unwanted transter was most intensive in the presence of water. An incorporation of additional deuterium besides the 4‐position of phenylalanine takes place simultaneously with the dehalogenation especially of the chloro derivative.
Synthesis of disodium (+)‐(Z)‐[[[1‐(2‐amino‐4‐[2‐14c]thiazolyl)2‐[[(2s,3s)‐2‐(carbamoyloxymethyl)‐4‐oxo‐1‐sulfonato‐3‐azetidinyl]amlno]‐2‐oxoethylidene]amino]oxy]acetate
Authors: Imanishi M. , Tomimoto M. , Watanabe M. , Hayashi N.
Published: October 2006

Disodium (+)‐(Z)‐[[[1‐{2‐amino‐4‐[2‐14C]thiazolyl)‐2‐[[ (2S,3S)‐2‐(carbamoyloxymethyl)‐4‐oxo‐1‐sulfonato‐3‐azetizinyl]amino‐2‐oxoethylidene]amino]oxy]acetate ([14C]AMA‐1080) was synthesized via [2‐(2‐chloroacetamido‐4‐[2‐14C]thiazoiyl)‐(Z)‐2‐(4‐nltrobenzyloxycarbonylmethoxyimino)]acetic acid from [14C]thiourea. Trisodium (+)‐(Z)‐[[[1‐(2‐amino‐4‐[2‐14C]thiazoiyl)‐2‐[[(1S, 2S)‐3‐carbamoyloxy‐1‐carboxylato‐2‐sulfonato‐aminopropyl]amino]‐2‐oxoethylidene]amino]oxy]acetate ([ 14C]AMA ‐1294) as the principal metabolite of [14C]AMA‐1080 was also prepared.
Synthesis of NO‐carrier added 11C‐labelled [methyl]choline analogs
Authors: Diksic Mirko , Jolly Dean
Published: October 2006

We describe here the synthesis of two[11C‐methyl]labelled analogs of choline and the influence of the solvent, addition of a base, and reaction time on the radiochemical yield. The reactions produced equally good yields in methanol and acetonitrile and reached maximum radiochemical yield at about 5‐10 min. The addition of a base in the case of [11C‐methyl]pyrrolidinocholine increases the radiochemical yield. Optimum radiochemical yields were 30% for[11C‐methyl]piperidinocholine and 40% for[11C‐methyl]pyrrolidinocholine for two choline analogs.
Synthesis of 7α‐chloro‐16α‐methylprednisolone 17α,21‐dipropionate‐4‐14c (alclometasone dipropionate‐4‐14c)
Authors: Terasawa Tadao , Atsumi Kazunori , Yokoshima Tetsuyoshi , Ohyabu Shintaro , Fukasaku Noboru
Published: October 2006

Grignard reaction of the enol‐lactone 8 with 14C‐methylmagnesium iodide afforded an adduct 9 which on subsequent treatment with lithium 2,6‐di‐t‐butylphenoxide gave the enone 10. Conversion of 10 to the trienone 12 was performed by two‐step dehydrogenation using chloranil and then DDQ. The protecting groups were removed on treatment whith 2N‐hydrochloric acid‐trifluoroacetic acid to give the triol 13. The 17α,21‐bisesterification of 13 was carried out according to the orthoester procedure. Finally, addition of dry hydrogen chloride to the resulting diester 16 led to the title compound 17.
A practical preparative scale synthesis of d/l‐6‐fluorodopa
Authors: Grierson J. R. , Adam M. J.
Published: October 2006

A practical preparative scale synthesis of D/L‐6‐fluorodopa (6‐FD) is presented. From veratric acid the procedure affords D/L‐6‐FD in 12% overall yield in 11 steps. Useful batch quantities ( > 300 mg) of this material were readily obtained and used as an analytical standard for 19F NHR and HPLC analyses in the preparation of L‐[18F]6‐fluorodopa.
Synthesis of tritium labeled 2,3,4,5‐tetrahydro‐1H‐3‐benzazepines
Authors: Landvatter Scott W. , Blackburn Dale W. , Villani Anthony J. , Bosch Gregory K.
Published: October 2006

SKF 82526 (6‐chloro‐7,8‐dihydroxy‐1‐(4‐hydroxyphenyl)‐2,3,4,5‐tetrahydro‐1H‐3‐benzazepine) has been synthesized in both racemic mono and enantiomerically pure ditritiated form; SKF 38393 (7,8‐dihydroxy‐1‐phenyl‐2,3,4,5‐tetrahydro‐1H‐3‐benzazepine) has also been labeled with tritium. In each case labeling was accomplished via tritiation of the appropriate ring halogenated precursor with tritium gas over Pd catalyst in triethylamine in DMF.
Synthesis of 4‐13C and 3,5‐13C labeled aniline as precursor of 13C ‐ labeled monosubstituted benzenes
Authors: Rumpel Helmut , Limbach Hans‐Heinrich
Published: October 2006

Aniline (IV), specifically 13C labeled in the 4‐ or in the 3,5‐position (IVa and IVb), has been synthesized with 55% yield from 13C labeled p‐nitrophenol (II). The reduction of the NO2 group and the removal of the OH group was performed in one step by reduction and hydrogenolytic cleavage of p‐nitrophenol‐methanesulfonate (III), prepared in 90% yield from (II). From (IV) a number of specifically 13C labeled monosubstituted benzenes C6H5Y (Y = CN, Hal, NO2) are easily accessible.
Preparation and purification of [14C] labeled N‐demethyl lincomycin and propylproline from [14C] tyrosine
Authors: Hausknecht E. C. , Wolf H. J.
Published: October 2006

Propylproline and N‐demethyl‐lincomycin, two intermediates in lincomycin biosynthesis, were prepared in radiolabeled form. [14C]‐labeled N‐demethyl‐lincomycin was synthesized by a resting cell suspension of a lincomycin negative mutant of Streptomyces lincolnensis that was fed methylthiolincosaminide and uniformly labeled [14C]‐tyrosine. [14C]‐N‐demethyl‐lincomycin was isolated from the culture medium by ion exchange chromatography and reverse phase‐ion pair high pressure liquid chromatography. [14C]‐propylproline was generated by the base hydrolysis of [14C]‐N‐demethyl‐lincomycin and isolated by anion exchange chromatography. The products had radiochemical purities greater than 95% and specific activities of 5.9 mCi/mmole.
New N‐permethylations and introduction of deuterium labelled methyl groups into primary and secondary amines
Authors: Giumanini Angelo G. , Verardo Giancarlo , Gei Maria H. , Lassiani Lucia
Published: October 2006

The extension of the N‐permethylation reaction of amines to aromatic amines with strong electron withdrawing substituents in o‐ and p‐ positions is reported. A comparison of this method with other “best” last step synthetic methods reported in literature is given. The reaction could be extended to the syntheses of N‐permethyl‐derivatives of amines of the type CH3‐nDn by use of formaldehyde, dideuteroformaldehyde, sodium borodeuteride and ‐hydride. Label conservation in the reaction is complete: the final step in the reaction involves H− (or D−) transfer from the reducing agent to a reactive species. The MS of the labelled compounds revealed extensive label excange in the ionization chamber. A new homogeneous procedure for the N‐permethylation, especially suited for larger scale preparations, is described.
A convenient synthesis of carbon‐13 labeled 1‐keto‐7‐methoxyoctahydrophenanthrene
Authors: Mohammadi Mohammad , Kabalka George W. , Finn Ronald D.
Published: October 2006

Carbon‐13 labeled 1‐keto‐7‐methoxy‐1,2,3,4,9,10,11,12‐octahydrophenathrene (III) and 1‐keto‐7‐methoxy‐2‐methyl‐1,2,3,4,9,10,11,12‐octahydrophenanthrene (IV) were prepared in good yields via the cyanidation of an organoborane.
Synthesis of deuterium labeled 1,3‐dimethyluric acid
Authors: Mamada Kumiko , Furuta Takashi , Kasuya Yasuji
Published: October 2006

A synthetic procedure for 1,3‐di(trideuteromethyl)uric acid is described. Deuterium labeling of the N‐1 and N‐3 positions was achieved by methylation of 4‐amino‐5‐carbethoxyuracil with di(trideuteromethyl)‐sulfate followed by cyclization of the dimethylated intermediate by heating. The synthesis resulted in a product with 99.4% d6 isotopic purity, which is selectively deuterated in the methyl groups at the N‐1 and N‐3 positions and chemically pure.
Synthesis and 1H‐nmr of deuterium labeled D,L‐homoserine lactone hydrochlorides
Authors: Ramalingam Kondareddiar , Woodard Ronald W.
Published: October 2006

The synthesis of six regiospecific deuterated D,L‐homoserine lactone hydrochlorides from the appropriately deuterated 2‐bromo‐1‐(tetrahydropyranyloxy) ethanes which were obtained by reduction of the corresponding ethyl bromoacetates are described. The proton nmr of each lactone is recorded and the chemical shift and coupling constants are reported.
The preparation and characterization of (±)‐[phenoxy‐3H(N)] phenoxybenzamine hydrochloride at high specific activity
Authors: Filer Crist N. , Fazio Robert , Morrison John , Ahern David G.
Published: October 2006

(±)‐Phenoxybenzamine is a ligand capable of irreversibly alkylating the alpha‐1 adrenergic receptor. Previous attempts to radiolabel it have achieved only low specific activities which impeded their use in neurochemical investigations. (±)‐[Phenoxy‐3H(N)] Phenoxybenzamine.HCL (1) has been prepared in our laboratory by the catalytic reductive aryl debromination of an appropriate brominated precursor with tritium gas. 3H NMR showed exclusive radiolabeling on the phenoxy ring and the radioligand had a specific activity of 32.4 Ci/mmol.
Synthesis of carbon‐14 labelled ropivacaine, a local anaesthetic agent
Authors: Sahlberg Christer
Published: October 2006

Ropivacaine hydrochloride monohydrate (LEA 103) is a new local anaesthetic agent which currently is under preclinical and clinical investigation. The preparation of (S)‐N‐(2,6‐[2‐methyl‐14C]dimethylphenyl)‐1‐propylpiperidine‐2‐carboxamide hydrochloride monohydrate (6, [14C]‐LEA 103) with a specific activity of 12.44 mCi/mmol is described. The key step in the synthesis is a Pd(II)‐mediated reaction of (S)‐1‐benzyloxycarbonyl‐N‐(2‐methylphenyl)‐piperidine‐2‐carboxamide (3) with [14C]methyl iodide. Also described is the preparation of compound 3 from (S)‐2‐piperidinecarboxylic acid.
Catalytic tritiation and 3H NMR spectroscopy of selected imidazoles and epoxides
Authors: Barton John M. , Jones John R. , Poncipe Carlo , Wright William W. , Zhang Li Ming
Published: October 2006

A number of imidazoles and epoxides, important for the study of the mechanisms of epoxy resin cure, have been tritiated by one‐step catalytic procedures. Tritium nuclear magnetic resonance spectroscopy has been employed to determine the positions and extent of labeling in these compounds and the observed pattern of labeling is discussed.
Synthesis of racemic [2′‐13C]tryptophan
Authors: Branchini B. R. , Prendergast F. G. , Spencer G. A. , Hugdahl J. D. , Ray B. D. , Kemple M. D.
Published: October 2006

[2‐13C] Indole was synthesized in 39% yield by a three‐step procedure starting with K13CN. The labeled indole was converted to D,L[2′‐13C] tryptophan in three subsequent steps and the overall yield from K13CN was 13.5%. Proton and 13C‐NMR, and GC/mass spectral analyses confirmed the position and extent of 13C incorporation.
A convenient synthesis of 8‐ and 12‐carbon deuterium‐labelled aldehydic esters for use in the preparation of labelled fatty acids
Authors: Adlof R. O.
Published: October 2006

Methyl 8‐oxooctanoate‐4,5‐d2 and methyl 12‐oxododecanoate‐4,5,8,9‐d4 were prepared for use as intermediates in the synthesis of a series of labelled fatty acid methyl esters. Synthesis of the two compounds began with monoozonization and sodium acetate cleavage of 1,4‐cyclooctadiene and 1,5,9‐cyclodedecatriene, respectively. The resultant unsaturated aldehydic acids were converted to the acetal esters. The acetal esters were deuterated with Wilkinson's catalyst and hydrolyzed to the deuterium‐labelled aldehydic esters. Overall yields were 47% and 49% and isotopic purities 97% and 89%, respectively.
Synthesis of 3,7‐dimethyl‐9‐(4′‐(3H‐diazirinyl)‐2′,6′‐dimethylphenyl)‐2E, 4E, 6E, 8E‐nonatetraenal‐1‐3H, A photoaffinity labeling analogue of all‐trans‐retinal
Authors: Sonnewald Ursula , Seltzer Stanley
Published: October 2006

The synthesis and spectroscopic properties of the title compound as well as its precursors are described.
Phase transfer mediated synthesis of radiolabelled alkyl aryl ethers and sulphides
Authors: Bergman Åke , Wachtmeister Carl Axel
Published: October 2006

Tritium‐ or 14C‐labelled methyl iodide and ethyl iodide were used for alkylations of phenols and thiols. The reactions were performed in a two‐phase system with phase transfer catalysis at room temperature. Products of high specific activity were isolated in isotope yields ranging from 38% to 100%.
Comparison of 99mTc‐halogenated iminodiacetates in experimental animals
Authors: Chiotellis E. , Varvarigou A.
Published: October 2006

The preparation of 99mTc‐N(3,4,5‐triiodo)‐acetanilido‐iminodiacetate (99mTc‐TIIDA) is described. This new labeled compound was studied in normal experimental animals as well as in animals with depressed hepatobiliary excretion. The results were evaluated in comparison to 99mTc‐bromotrimethyl IDA (99mTc‐MEBROFENIN) a technetium chelate already used in diagnosis, as well as to 99mTc‐iodotrimethyl IDA (IODOFENIN) a recently reported agent and highly specific for the hepatobiliary system. 99mTc‐TIIDA was totally excreted via the hepatocytes in healthy animals but proved less effective in animals with depressed hepatobiliary excretion.
Synthesis of [methoxy‐14C]eugenol
Authors: Rice Joseph E. , Hussain Nalband , Lavoie Edmond J.
Published: October 2006

A short, efficient synthesis for [methoxy‐14C]eugenol from unlabelled eugenol is described. The free phenolic group is protected as a methanesulfonate ester prior to removal of the methoxyl group. Reaction of the resulting phenolic mesylate with [14C]methyl iodide under basic conditions followed by treatment with warm sodium hydroxide gave the title compound in good overall yield.
Synthesis of methyl [2‐13C‐2,2‐d2]‐ and [3‐13C‐3,3‐d2]tetracosanoate
Authors: Pomonis J. George , Hakk Heldur
Published: October 2006

The synthesis of methyl [2‐13C‐2, 2‐d2]‐ and methyl [3‐13C‐3, 3‐d2]tetracosanoate is reported. The carbon‐13 was introduced by cyanation of 1‐bromodocosane and 1‐bromoheneicosane using 18‐crown‐6 ether and potassium [13C]cyanide in hexamethylphosphoramide. Cyanation reactions with carbon‐13 proceeded at better than 90% yield by this method. Triphasic catalysis was used to introduce the CN group in successive homologations of the labeled compounds. This method was found to be label‐sparing with typical yields being 95%. No scrambling of deuterium was observed.
Synthese von trinatrium‐phosphono/14C/formiat
Authors: Issleib K. , Bubner M. , Balszuweit A.
Published: October 2006

Trisodiumphosphono/14C/formate (TPF) has been prepared in high chemical and radiochemical purity by carboxylation of sodium‐di‐n‐butylphosphite with 14CO2, subsequent alkylation with dimethyl‐sulfate to di‐n‐butylphosphonomethyl/14C/formate and dealkylation of the latter with aid of trimethylbromosilane and alkaline hydrolysis.

Whereas in trisodiumphosphono/14C/formate the radioactive carbon has been observed to be stable in its position, the 14C in sodium‐di‐n‐butyl‐phosphono/14C/formate may be quantitatively exchanged with CO2.
Gadolinium labeled pharmaceuticals as potential mri contrast agents for liver and biliary tract
Authors: Najafi A. , Amparo E. E. , Johnson R. R.
Published: October 2006

Three gadolinium‐labeled compounds, potential nuclear magnetic resonance (NMR) imaging contrast agents for liver and biliary tract, were studied: 1 Gd‐DISIDA, 2( Gd‐DTPA‐Liposomes, and 3) Gd‐DTPA dihexadecylamide (Gd‐diamide). In each case, “Carrier Added” Gd‐153 with specific activity of about 5uCi/mg was used. Each labeled compound was evaluated in experimental animals. Gd‐DISIDA proved unsatisfactory because of in vivo instability. Gd‐DTPA‐Liposomes demonstrated strong toxic effects probably due to pulmonary embolism when large amounts of this compound was administered intravenously. Gd‐diamide showed good uptake in the hepatocytes with subsequent excretion into the biliary tract. Several rabbits were imaged in a 0.6T NMR imaging system before and after injection of Gd‐diamide. Pulse sequences were chosen that would yield T1‐weighted images and permit calculation of T1 relaxation times. This compound produced significant shortening of the T1 relaxation times of the liver and observable increase in intensity on the T1‐weighted images. Gd‐diamide shows promise as potential NMR contrast agent for liver and biliary tract imaging.
Synthesis of a [3H]‐labelled derivative of the microtubular poison taxol
Authors: Chenu J. , Takoudju M. , Wright M. , Senilh V. , Guénard D.
Published: October 2006

A labelled derivative of the microtubule poison taxol has been developed on acetylation of the 7‐OH function of taxol with [3H] acetic anhydride. The [3H] 7‐acetyl taxol synthesized was chemically and radiochemically pure and has not undergone radiolysis during 1.5 years. This compound was also stable in the presence of microtubule proteins. The ID50 of 7‐acetyl taxol for stabilization of microtubules was two times the ID50 of taxol. Hence it can be used as a probe for biological studies. The acetylation of the hydroxyl group at position C‐7 is a general method applicable to other taxol derivatives as starting compounds.
Synthesis of N‐[N‐[(S)‐1‐ethoxy[14C]carbonyl‐3‐phenyl[1‐14C]propyl]‐L‐alanyl]‐N‐(indan‐2‐YL)glycine hydrochloride ([14C]CV‐3317)
Authors: Watanabe Masazumi , Tada Norio , Itoh Katsumi , Hayashi Nobuyoshi
Published: October 2006

N‐[N‐[(S)‐1‐Ethoxycarbonyl‐3‐phenylpropyl]‐L‐alanyl]‐N‐(indan‐2‐yl)glycine hydrochloride (CV‐3317), a new potent angiotensin converting enzyme inhibitor, was labeled with carbon‐14. Diethyl [U‐14C]oxalate was condensed with ethyl 3‐phenylpropionate, subsequently decarboxylated to yield ethyl [1,2‐14C]‐2‐oxo‐4‐phenylbutyrate. The reductive condensation of the latter with tert‐butyl N‐L‐alanyl‐N‐(indian‐2‐yl)glycinate followed by hydrolysis afforded [14C]CV‐3317 in an overall radiochemical yield of 17.4 %.
Synthesis of mevalonolactone double labelled with carbon 13C at positions C‐2 and C‐4
Authors: Zamir Lolita O. , Nguyen Cong‐Danh
Published: October 2006

The total synthesis of the title compound from pyruvic aldehyde dimethyl acetal and ethyl [2‐13C]acetate is reported.
S‐Adenosyl‐L‐(1‐14C)‐homocysteine
Authors: Thomas H. Jeanette , Montgomery John A.
Published: October 2006

S‐Adenosyl‐L‐(1‐14C)‐homocysteine (3) was prepared from commercially available L‐(1‐14C)‐methionine (1) by conversion first to S‐benzyl‐L‐(1‐14C)‐homocysteine (2), which upon treatment with sodium in liquid ammonia gave the disodium salt of L‐(1‐14C)‐homocysteine. Reaction of this sodium salt with 5′‐O‐tosyladenosine gave 3.
Tropanol‐Metallocen‐Carbonsäre‐Ester – Synthesen, Markierung Mit 103Ru und 103mRh und Organverteilung
Authors: Wenzel M. , Wu Y.
Published: October 2006

Im Rahmen unserer Untersuchungen über markierte Ruthenocen‐Derivate als Radiopharmaka (1 ‐ 3) haben wir den Ester aus Tropanol und Ferrocen‐, bzw. Ruthenocencarbonsäure hergestellt und die Ruthenocen‐Verbindung mit 103Ru markiert. Angesichts der pharmakologischen Wirkungen verschiedener Tropanolester (4) haben wir die Organ‐Verteilung der markierten Tropanolester bei Ratten und Mäusen untersucht.
N.C.A. 18F‐fluoroalkylation of H‐acidic compounds
Authors: Block Dirk , Coenen Heinz Hubert , Stöcklin Gerhard
Published: October 2006

The fluoroalkylation of H‐acidic compounds in the presence of the aminopolyether 2.2.2./potassium carbonate complex was systematically studied. With acetonitrile as solvent nucleophilic fluorination and subsequent fluoroalkylation can be carried out in a one‐pot mode. Using the bifunctional fluoroalkanes 18F(CH2)nX (n = 1‐3, X = Br, OMes, OTos) the best n.c.a. labelling yields were obtained with tosylates. Fluoroethylation and fluoropropylation of phenol gave rise to radiochemical yields of ≥ 90% under optimized conditions within 10 min. The fluoroethyl moiety is the smallest generally applicable fluoroalkylation agent. In a series of H‐acidic compounds a strong influence of their pKa value on the fluoroethylation reaction was observed. Besides H‐acidic compounds all Lewis bases are principally potential substrates for n.c.a. 18F‐fluoroalkylation.
Preparation of β ‐alanine‐3,3‐D2 and −2,2,3,3‐D4
Authors: Hanai Kazuhiko , Kuwae Akio
Published: October 2006

β‐Alanine‐3,3‐d2 and −2,2,3,3‐d4 were prepared via a five‐step procedure from ethyl cyanoacetate. The procedure involves reduction of the starting material with lithium aluminum deuteride, followed by benzoylation of the amino alcohol obtained, oxidation of the benzoylated compound, hydrolysis of benzoyl‐β‐alanine‐3,3‐d2 with hydrochloric or deuterochloric acid, and then anion exchange of the hydrochloride or the deuterochloride. The isotopic purities of the d2 and d4 compounds were more than 98 and 97%, respectively.
Synthesis of [14C]hippuryl‐L‐histidyl‐L‐leucine
Authors: Prior K J , Wiltshire H R , Smith G M
Published: October 2006

This paper describes the synthesis of [14C]hippuryl‐L‐histidyl‐L‐leucine (hip‐his‐leu) from barium [14C]carbonate. An overall radiochemical yield of 36% was obtained giving pure material with a specific activity of 17 mCi/mmol and a suitable substrate for the assay of angiotensin converting enzyme (ACE).
An improved synthesis of [5′‐3H]‐3′‐azido‐3′‐deoxythymidine, tritiated zidovudine
Authors: Hill John A. , Andrew Freeman G.
Published: October 2006

[5′‐3H]‐3′‐Azido‐3′‐deoxythymidine (3) was prepared at a specific activity of 14.0 Ci/mmol by a two‐step synthetic sequence involving controlled oxidation of the unlabelled compound (1) to the 5′‐aldehyde (2) followed by reduction with [3H]‐NaBH4. Purification was performed by preparative TLC. The radiochemical purity was 99.2%.
The synthesis of multiple deuterated N‐n‐propyl‐norapomorphine N‐(d7) and derivatives
Authors: Gao Yigong , Traino Thomas M. , Vouros Paul , Neumeyer John L.
Published: October 2006

NPA has been labelled using n‐propyl iodidie (d7) through alkylation of norcodeine followed by a multistep route which also affords the related deuterated analogs N‐n‐propylnorapocodeine (d7), the prodrug 10,11‐methylenedioxy‐NPA (d7) and 10,11‐dimethoxy‐NPA (d7).
Synthesis of tetradeuterated buspirone
Authors: Dischino D. D. , Covington R. R. , Combs C. M. , Gammans R. E.
Published: October 2006

Two methods have been developed for the synthesis of tetradeuterated buspirone. Synthesis of the title compound was accomplished by the reaction of 1‐(2‐pyrimidinyl)piperazine‐3,3,5,5‐d4 or 1‐(2‐pyrimidinyl)‐piperazine‐2,2,3,3,‐d4 with 8‐(bromobutyl)‐8‐azaspiro[4.5]decane‐7,9‐dione in refluxing acetonitrile.
Synthesis of racemic [2‐14C] insect juvenile hormone III
Authors: Adams Paul H.
Published: October 2006

Both racemic [2‐14C] juvenile hormone III (JH III; methyl‐10,11‐epoxy‐3,7,11‐trimethyl‐2(E),6(E) [2‐14C]dodecadienoate) and its 2‐(Z) isomer were synthesised on a 1 millimolar scale by forming the 9,10 epoxide of geranyl acetone and reacting this with the anion of trimethylphosphono‐[2‐14C]acetate. After purification the yield of [2‐14C] JH III in the radiosynthetic step was 14% (with purity >93% by GC, specific activity 0.4mCi/mmol) and 4.7% (>97%, 0.4mCi/mmol) for the 2‐(Z) isomer.
Synthesis of deuterium labelled thioridazine via ruthenium tetroxide oxidation of the piperidine ring
Authors: Mohammad T. , Midha K. K. , Hawes E. M.
Published: October 2006

A multistep synthetic route to (±)‐10‐[2‐(1‐methyl‐2‐piperidinyl)ethyl]‐2‐methylthio‐10H‐phenothiazine (thioridazine) was developed which allowed for the incorporation of two deuterium atoms in the piperidine ring and a further two in the 1‐position of the ethyl side chain. The key steps involved ruthenium tetroxide oxidation of N‐protected methyl 2‐piperidinylacetate and subsequent lithium aluminum deuteride reduction of 2‐(2‐hydroxyethyl)‐1‐methyl‐6‐piperidinone or the corresponding piperidinoneester. The isotopic purity of the dideuterated and tetradeuterated products was greater than 99%.
Synthesis of 3H‐ and 14C‐labeled tracers for studies of functional monoamine oxidase activity
Authors: Halldin Christer , Bjurling Peter , Långström Bengt , Macgregor Robert R. , Fowler Joanna S. , Wolf Alfred P.
Published: October 2006

The 3H‐labeling of clorgyline, L‐deprenyl, N,N‐dimethylphenethyl amine and N‐methylphenethyl amine as well as the 14C‐labeling of clorgyline and L‐deprenyl are described. Labeling was accomplished by N‐alkylation of the free base of the corresponding desmethyl compound, using 3H‐methyl iodide, or by a reductive alkylation using 14C‐formaldehyde. The crude products were purified by semipreparative HPLC. The total radiochemical yield was 31‐65% based on 3H‐methyl iodide and 60% based on 14C‐formaldehyde. The radiochemical purity was greater than 99%.
Syntheses Du S 9490‐3: Sel De Terbutylamine De l'Acide {[Carbethoxy‐1 (1S) Butyl Amino] OXO‐1 (2S) Propyl} (2S, 3aS, 7aS) Perhydro Indole ‐ Carboxylique‐2 [Cyclohexyl ‐14C‐U], du S 9780 : Acide {[Carboxy‐1 (1S) Butyl Amino] OXO‐1 (2S) Propyl} (2S, 3aS, 7aS) Perhydro Indole‐Carboxylique‐2 [Cyclohexyl‐ 14C‐U], du S 9490‐3 [Butyl‐(3H‐3,4) Amino] et du S 9780 [Butyl‐(3H‐3,4)‐Amino] A Hautes Radioactivites Specifiques
Authors: Pichat L. , Tostain J. , Gomis J. M. , Coppo M. , Moustier A. M. , Vincent M. , Remond G. , Portevin B. , Laubie M.
Published: October 2006

Synthesis of S 9490‐3 [U‐14C‐cyclohexyl] 1‐{[(2S) 2 ‐ [(1S) 1‐(carbethoxybutyl) amino] 1‐oxopropyl} (2S, 3aS, 7aS) perhydroindole‐2‐carboxylic acid terbutylamine salt 1 and S 9780 [U‐14C‐cyclohexyl]1‐ {[(2S) 2 ‐ [(1S)1‐ carbethoxybutyl] amino]1‐ oxopropyl} (2S, 3aS, 7aS) perhydroindole‐2‐carboxylic acid and of [3,4‐3H‐butylamino] S 9490‐3 and [(3,4‐3H‐) butylamino] S 9780, potent inhibitors of angiotensin converting enzyme at very high specific radioactivities.

[U‐14C] Aniline 3 with a specific activity of 120 mCi / mM was converted in a one pot reaction into the [U‐14C] phenyl hydrazone of ethyl pyruvate 6 via [U‐14C] phenyl diazonium chloride 4 in a 66% overall yield. Cyclization of 6 with PPA in xylene gave [U‐14C] phenyl 2‐carbethoxy indole 7 in a 39.5% yield. Catalytic hydrogenation of 7 in the presence of platinum gave [U‐14C‐cyclohexyl] (RS) ‐ 2 ‐ carbethoxy perhydroindole 8 which was saponified to the corresponding acid 10 which was reesterified to the benzylester 11. Racemic 11 was condensed with N‐ [(S) 1‐ carbethoxybutyl] (S) alanine in presence of DCC and 1 ‐ hydroxy ‐ 1 benzotriazole. The resulting 12 was separated from the mixture of isomers by a silicagel column chromatography. [U‐14C‐Cyclohexyl] S 9490‐3 1 was obtained from 12 by hydrogenolysis in a 1.7% overall yield from [U‐14C] aniline. [U‐14C Cyclohexyl]‐ S 9780 2 was made in a 50% yield by mild saponification of : 1.

Cyanoborohydride reductive amination of pyruvic acid with ethyl (S) C‐ allylglycinate gave a mixture of epimers 15 and 16 from which [ N ‐ (S) 1 ‐ ethoxycarbonyl ‐ 3 ‐ butenyl ] ‐ (S) alanine 15 was isolated. The latter condensed with 2 ‐ t ‐ butyloxycarbonyl (25, 3aS, 7aS) perhydroindole 17gave18, which on hydrochloric acid hydrolysis gave 1 ‐{[ (25)] 2 ‐ [ (1S) 1 ‐ carbethoxy ‐ 3 ‐ butenyl] amino]‐1 ‐ oxopropyl} (2S, 3aS, 7aS) perhydroindole ‐ 2 ‐ carboxylic acid 13 a dehydro analog of S 9490. Tritiation of 13 with tritium gas in the presence of PdIc in THF gave [ 3,4 ‐ 3H ‐ butylamino] (S) 9490‐3 with a specific activity of 52 Curies ImM. Saponification of a fraction of [3H] S 9490‐3 gave [3,4 ‐ 3H ‐ butylamino] S 9780 with a specific activity of 52 Curies/mM in low yield.
14C‐labeling of isomeric perfluoroalkyl carboxanilide mixtures via electrofluorination
Authors: Gajewski Robert P. , Terando Norman H. , Berard David F.
Published: October 2006

Electrofluorination of benzoyl chloride‐ring‐UL‐14C produced an isomer mixture of cyclic C6F11 carbonyl fluorides, principally 1,2,2,3,3,4,4,5,5,6,6‐undecafluorocyclohexane‐ring‐UL14C carbonyl fluoride, which was derivatized with 2‐bromo‐4‐nitroaniline and triethyl amine. The resultant carboxanilide mixture is designated as EL‐499 labeled with 14C in the perfluoro alkyl ring for use in metabolic studies.
A convenient synthesis of functional [2‐2H]cyclohexa‐1, 4‐dienes via vinyl organotin reagents
Authors: Jousseaume Bernard , Villeneuve Patrice
Published: October 2006

1‐ and 6‐substituted [2‐2H]cyclohexa‐1,4‐dienes were prepared by the electrophilic cleavage of tin‐vinyl bonds in functional tributylstannyl‐2‐cyclohexa‐1,4‐dienes by deuteriated trifluoroacetic acid.
2‐18F‐phenylalanine and 3‐18f‐tyrosine — synthesis and preliminary data of tracer kinetics
Authors: Murakami M. , Takahashi K. , Kondo Y. , Mizusawa S. , Nakamichi H. , Sasaki H. , Hagami E. , Iida H. , Kanno I. , Miura S. , Uemura K.
Published: October 2006

2‐18F‐phenylalanine and 3‐18F‐tyrosine were synthesized by direct electrophilic substitution of L‐phenylalanine and L‐tyrosine with 18F‐acetylhypofluorite. Both compounds were obtained in 30 % radiochemical yield based on 18F‐acetylhypo‐fluorite within 60 min after the end of irradiation. In ratbrain, 30 % of the radioactivity was fixed into acid‐insoluble macromolecules and most of the free radioactivity existed as amino acids at one hour after 2‐18F‐phenylalanine injection. In the case of 3‐18F‐tyrosine, significant amounts of radioactivity existed as organic acids. The catecholamine fraction had negligible radioactivity in both cases. These results indicate that 2‐18F‐phenylalanine is suitable for compartmental analysis for tissue accumulation because of its simple metabolic behavior.
Synthesis of 3H‐ and 14C‐ketanserin
Authors: Janssen Cor G. M. , Lenoir Herman A. C. , Thijssen Jos B. A. , Knaeps Alfons G. , Verluyten Willy L. M. , Heykants Jozef J. P.
Published: October 2006

Ketanserin, 3‐[2‐[4‐(4‐fluorobenzoyl)‐1‐piperidinyl]ethyl]‐2,4(1H,3H)‐quinazol‐inedione is a new serotonin S2‐receptor blocking agent used in hypertension and related diseases. Pharmacokinetic studies required the synthesis of monolabelled 3H‐ and 14C‐ketanserin tartrate. The tritium compound had the label placed at the fluorobenzoyl moiety, whereas for 14C‐ketanserin the heterocyclic part of the quinazolinedione system was chosen. Receptor binding studies and application in radioimmunoassay necessitated the synthesis of a molecule at higher specific activity, hence a dilabelled molecule was constructed with tritium atoms placed at opposite positions in the molecule.

The title compounds were obtained at specific activities of 169.5, 5.66 and 34900 mCi/mmol, respectively and with HPLC purities of > 98%.
An improved synthesis of Carbon‐14 labelled carboxylic acids from Carbon‐14 labelled amino acids
Authors: Ramamurthy T. V. , Ravi S. , Viswanathan K. V.
Published: October 2006

Various Carbon–14 labelled amino acids including the aromatic ones viz., tyrosine, phenylalanine and tryptophan are converted to the corresponding carboxylic acids in high yield (70–;90%) on a micromolar scale synthesis by reaction with hydroxyl‐amine‐o‐sulphonic acid and in a short reaction time. The improvement in yield has been achieved by using aqueous alcohol as solvent in lieu of water alone as the medium of reaction.
Synthesis of 14C‐dilevalol
Authors: Duelfer Timothy , Duffin Raymond J. , Youngstrom Richard E.
Published: October 2006

[1‐14C]‐Dilevalol, (Figure 1), was synthesized from [1‐14C]‐acetyl chloride. A key step in the synthesis, the coupling of a protected chiral amine with a bromoketone, was very sensitive to the choice of protecting group. The authors attribute this sensitivity to unexpected and severe radiolytic decomposition of the reaction product. The use of a simple benzyl. protecting group rather than an α‐methyl benzyl protecting group avoided most of the apparent autoradiolysis.
Synthesis of tritium labeled arbaprostil and related 15‐ methyl prostaglandins
Authors: Hsi Richard S. P. , Yankee Ernest W. , Stolle Wayne T.
Published: October 2006

This report describes the synthesis of arbaprostil, a cytoprotective antiulcer agent, and a group of related 15‐methylprostaglandins, labeled with tritium at the C‐11 position, from 15(R)‐ and 15(S)‐15‐methylprostaglandin D2 methyl esters. Radiolytic decomposition of the labeled product and some intermediates, and purification by preparative high performance liquid chromatography, and storage of [3H]‐arbaprostil are also discussed.
Synthese de formaldehyde tritie a haute activite specifique en vue du marquage des proteines
Authors: Coppo M. , Rousseau B. , Beaucourt J. P.
Published: October 2006

In order to label proteins with tritium in high specific activity, we synthesized 3H‐formaldehyde with a specific activity of about 15 Ci/mmol (555 GBq/mmol). The method is suitable for the synthesis of about 100 mCi (3.7 GBq) of tritiated formaldehyde directly used for the reductive methylation of proteins.
Evaluation of iminodiacetic acid derivatives of ortho and meta amino hippuric acid analogs as renal function agents
Authors: Bhargava Kuldeep K. , Zhang Zhuangyu , Chun Sam B. , Chervu L. Rao , Blaufox M. Donald
Published: October 2006

Iminodiacetic acid derivatives of meta amino hippuric acid (MAHIDA) and ortho amino hippuric acid (OAHIDA) have been synthesized in the course of our continuing investigation of 99mTc‐labeled hippuric acid analogs for application for renal function measurements. The two derivatives yielded stable 99mTc complexes using Sn(II) reduction method and are excreted rapidly via the GU tract as shown in animal biodistribution studies. Clearance of these two complexes is lower than that of the analog formed with para amino hippuric acid (PAHIDA) previously reported. Some aspects of structure activity relationship associated with PAHIDA point to the fact that para derivative has optimal renal excretory characteristics.
[3H]‐labelling of hydroxyethyl groups – synthesis of s‐2‐hydroxy [2‐3H] ethyl) glutathione and of [3H]‐melphalan
Authors: Verny M. , Nicolas C.
Published: October 2006

The easy preparation of 2‐bromo [1‐3H] ethanol allows the tritium labelling of molecules bearing S‐ or N‐ hydroxyethyl groups. Thus S‐(2‐hydroxy [2‐3H] ethyl) glutathione and [3M]‐Melphalan were synthesised with specific radioactivities of around 10 mCi/mmol (370 MBq/mmol). These values could be theoretically raised to 10 Ci/mmol (370 GBq/mmol), according to the specific activity of the labelling precursor, sodium [3H] borohydride.
Synthesis of 14C‐ and 35S‐labelled 2‐mercaptobenzimidazoles
Authors: Doerge Daniel R.
Published: October 2006

14C‐ and 35S‐labelled 2‐mercaptobenzimidazole and 1‐methyl‐2‐mercaptobenzimidazole were synthesized from 14C‐carbon disulfide, 35S‐thiourea, 14C‐methyl iodide and 35S‐thiourea, respectively, for use in studies on the mechanism of action of antithyroid drugs. The products were purified by chromatography on silica and isolated with radiochemical purities of greater than 98%, yields of 45‐77% and specific activities of 2.1‐5.3 mCi/mmole.
A convenient synthesis of CIS/trans‐3‐chloroacrylic acid‐UL‐14C
Authors: Roth G. A. , McKendry L. H.
Published: October 2006

A convenient method for oxidation of allylic alcohols to the corresponding carboxylic acids is described. A two phase (methylene chloride/aqueous) silver oxide oxidation circumvents isolation of the intermediate aldehydes, thus making the procedure well suited to microscale carbon‐14 synthesis. Although we required a mixture of cis/trans‐3‐chloro‐acrylic acid‐UL‐14C and thus began the preparation with cis/trans‐3‐chloroallyl alcohol‐UL‐14C, the reaction sequence can be carried out starting with either isomer to provide the isomerically pure carboxylic acids.
Synthesis of 13C‐ and 14C‐Labeled methanesulfinic and methanesulfonic acids
Authors: Feil V. J. , Huwe J. K. , Dulik D. M. , Fenselaum C.
Published: October 2006

The enzyme catalyzed displacement of the methyl sulfonyl group from pentachlorophenyl methyl sulfone, the m‐chloroperoxybenzoic acid oxidation of methyl mercaptan and the reaction of methyllithium with sulfur dioxide are methods described for the synthesis of isotopically labeled methanesulfinic acid. The first two methods can be carried out on a milligram scale and are suitable for high specific activity preparations while the latter method is suitable for preparations on a gram scale. Conditions are also given for the preparation of isotopically labeled methanesulfonic acid.
Synthesis of [3H]clozapine
Authors: De Paulis Tomas , Davis Daniel A. , Smith Howard E. , Malarek David H. , Liebman Arnold A.
Published: October 2006

[3H]Clozapine was prepared with a specific activity of 9.9 Ci/mmol by reaction of 8‐chloro‐11‐(methylthio)‐5H‐dibenzo[b,e][1,4]diazepine with an excess of [3H]N‐methylpiperazine. The latter was prepared from N‐methylpyrazinium bromide in ethanolic hydrogen chloride by reduction at room temperature with tritium over 5% rhodium on aluminum oxide.
The synthesis of 3H‐putrescine and subsequent biosynthesis of 3H‐jacobine, a pyrrolizidine alkaloid from Senecio Jacobaea
Authors: Reed R. L. , Buhler D. R.
Published: October 2006

A new method was developed for the preparation of tritiated putrescine dihydrochloride ([2,3‐3H]‐1,4‐diaminobutane dihydrochloride) from succinonitrile (1,4‐butanedinitrile) and 3H2O, with a radiochemical yield of 16%. Tritiated jacobine and other pyrrolizidine alkaloids were then biosynthesized in Senecio jacobaea using 3H‐putrescine·2HC as the precursor with a radiochemical yield of 0.9% into total pyrrolizidine alkaloids. Jacobine accounted for 36% of the total. This synthetic method provides a relatively inexpensive source for the preparation of these labelled compounds.
Marquage par 14C du Chloro‐2 Ethyl Isocyanate. Application au Marquage de Chloroethyl Tetrazinone et de Chloroethylnitrosourees
Authors: Madelmont J. C. , Moreau M. F. , Godeneche D. , Labarre P. , Veyre A.
Published: October 2006

Le chrloro‐2 éthyl isocyanate a étémarqué par 14C sur le groupe carbonyl à partir de l'acide chloropropionique‐14C.

La réaction de Curtius en présence de catalyseur de transfert de phase a été utilisée.

Les marquages de chloro‐2 éthyl tetrazinone et de chloro‐2 ethyl nitrosourées sont décritis.
Synthesis of D‐[1‐14C]penicillamine hydrochloride
Authors: Chien David H. T. , Ebert David A. , Roth Robert W.
Published: October 2006

Methods are described for the synthesis of DL‐[1‐14C]penicillamine and D‐[1‐14C]penicillamine hydrochloride from K14CN. The method consists of additon of H14CN to 2,2,5,5‐tetramethyl‐3‐thiazoline followed by hydrolysis of the resulting thiazolidine to DL‐penacillamine. Resolution was achieved through the salt of N‐formylisopropylidene‐DL‐penicillamine with (−)‐norephedrine. The specific activity of D‐penicillamine was 21.7 mCi/mmole and the overall radiochemical yield from K14CN was 3.3%.
Radioactively labelled epoxides. Part VI. tritium‐labelled mono‐ and dimethyl substituted phenyl oxiranes (styrene oxides)
Authors: Setiabudi Frans , Oesch Franz , Platt Karl L.
Published: October 2006

Tritium‐labelled (E)‐ and (Z)‐2,3‐dimethyl‐2‐phenyl oxirane 4, (E)‐ and (Z)‐2‐methyl‐3‐phenyl oxirane 7 and 2,2‐dimethyl‐3‐phenyl oxirane 11 have been prepared by reduction of the corresponding bromoketones with sodium borotritide to the corresponding bromohydrins followed by cyclization to the oxiranes. These oxiranes were successfully used as diagnostic substrates to distinguish between different forms of epoxide hydrolase and glutathione transferase.
Synthese d'Acide Benzisoxazole‐1, 2 Acetique‐3 (14C‐α) et (14c‐β)
Authors: Thourel P. , Noel J. P. , Beaucourt J. P.
Published: October 2006

Nous décrivons dans ce travail. deux synthèses de l'acide benzisoxazole‐1,2 acétique‐3 marqué respectivement au carbone 14 en positions α et ß. L'acide 14C‐α est obtenu à partir d'hydroxy‐4 coumarine (14C‐3) synthétisée à partir d'hydroxy‐1 acétophénone (14C‐CH3) obtenue par réaction de Fries.

L'acide 14C‐ß est synthétisé à partir d'hydroxy‐4 coumarine 14C‐2 obtenue à partir de carbonate d'éthyle 14C. Les positions de marquage ont été contrǒlées par spectrométrie de masse et ont confirmé le schéma réactionnel supposé du réarrangement en acide benzisoxazole‐1,2 acétique‐3.
Synthetic studies with [18F]p‐fluorobenzenediazonium chloride application to the synthesis of a radiolabelled glucocorticoid: [18F]WIN 44577
Authors: Feliu Anthony L.
Published: October 2006

A, route was devised to synthesize no‐carrier‐added or carrier‐added [10F]p‐fluorophenylhydrazine from aqueous [18F]fluoride. Key reaction in this three‐step sequence is the reduction of [18F]p‐fluorobenzenediazonium chloride with sodium cyanoborohydride. The utility of this method is demonstrated by the synthesis of [10F]WIN 44577, an N‐(pfluorophenyl)pyrazole‐containing corticosteroid, which exhibits exceptionally high in vitro binding affinity for type‐II glucocorticoid receptors, and which is currently under evaluation as a possible radioligand for positron emission tomographic studies.
Asymmetric tritiation of N‐acetyl α‐β dehydrotryptophanamide
Authors: Pinto‐Alphandary H. , Van Craeynest‐Jimonet C. , Morgat J. L. , Fromageot P.
Published: October 2006

Rhodium‐DiPAMP complex catalyzes the stereoselective addition of two tritium atoms on N‐acetyl −α −β dehydrotryptophanamide. The substrate was prepared by dehydrogenation of N‐acetyltryptophanamide with TSO (Tryptophan‐Side Chain oxidase) from Pseudomonas. Tritiated N‐acetyl‐tryptophanamide was obtained with the theoretical specific radioactivity (58 Ci/mmole). The enantiomeric excess of the L‐diasteroisomer reached 94.4 %. 3NMR spectra indicated the selectivity of 3H‐labelling on the Cα – Cβ double bond. This new approach of tritiation by homogeneous catalysis applied to tryptophanyl‐containing peptides is discussed.
Synthesis of acetaminophen‐d4
Authors: Johnston D. , Elder D.
Published: October 2006

A synthetic procedure for acetaminophen‐d4 (4′‐hydroxyacetanilide – 2′,3′,5′,6′‐d4) is described. The preparation was achieved in two steps from nitrobenzene‐d5 in an overall yield of 40%.
Preparation of folic acid specifically labeled with deuterium at the 3′,5′‐positions
Authors: Gregory Jesse F. , Toth John P.
Published: October 2006

A method was devised for the synthesis of 3′,5′‐[2H2]folic acid (d2‐folic acid) for use in studies of folate metabolism in human beings. Labeling was accomplished by catalytic dehalogenation of 3′,5′‐dibromofolate with deuterium gas and palladium/carbon catalyst. d2‐Folic acid was separated from reduced forms and residual 3′‐monobromofolate by chromatography on DEAE‐Sephadex. Analysis by proton NMR and mass spectrometry indicated 70–75% deuteration of the 3′,5′‐positions and lack of deuteration at other carbons.
A convenient synthesis of D‐[1‐11C]glucopyranose and D‐[1‐11C]galactopyranose using diborane
Authors: Tada Masao , Oikawa Atsushi , Matsuzawa Taiju , Itoh Masatoshi , Fukuda Hiroshi , Kubota Kazuo , Kawai Hiroaki , Abe Yoshinao , Sugiyama Hiroshi , Ido Tatsuo , Ishiwata Kiichi , Iwata Ren , Imahori Yoshio , Sato Tachio
Published: October 2006

Rapid chemical syntheses of D‐[1‐11C]glucopyranose and D‐[1‐11C]galactopyranose starting from D‐arabinopyranose and D‐lyxopyranose, respectively, are described. The use of diborane for reduction of intermediates in highly effective for reducing the time required.
Synthesis of [carbonyl‐14C]hexopal
Authors: Johnston D. , Elder D.
Published: October 2006

A synthetic procedure for producing [carbonyl‐14C]Hexopal (mesoinositol [carbonyl‐14C]nicotinate) is described. The synthesis is achieved in two steps using [carbonyl‐14C]nicotinic acid as the source of the radiolabel with an overall chemical yield of 75% and a radiochemical yield of 67%.
Near‐quantitative conversion of labelled acids to esters by modified hassner esterification. Synthesis of labelled triglycerides
Authors: Elbert Tomáš
Published: October 2006

The modification of the reaction conditions of Hassner esterification ‐ DCC/4‐dimethylaminopyridine method ‐ merely the gradual addition of DCC to the reaction mixture ‐ eliminated the unwanted side reaction ‐ N‐acyl‐N,N'‐dicyclohexylurea formation ‐ and thus improved the conversion of the acid to the desired ester. Glycerol tri[U‐14C]palmitate, glycerol tri[U‐14C]oleate and glycerol tri[9, 103H]stearate with molar activities greater than 1800 MBq.mmol−1 were prepared with preparative radiochemical yields about 86–92%.
The oxidative cleavage of amines by iodine monochloride
Authors: Ghaffari M. A. , Ali H. , Van Lier J. E.
Published: October 2006

The formation of secondary products during the radioiodination of aromatic amines is reported. Iodination of a series of N,N‐dimethyl‐N'‐(alkylphenyl)‐1,3‐propanediamines with IC1 in the presence of AcOH and HClO4 gave in addition to the expected iodo derivatives substantially amounts of secondary cleavage products which were identified as the corresponding iodobenzaldehyde derivatives.
Synthesis of carbon‐13 and carbon‐14 labeled paldimycin tri‐sodium salt
Authors: Hsi Richard S. P. , Witz Dennis F. , Visser Jeronimo , Stolle Wayne T. , Ditto Cathy L.
Published: October 2006

Carbon‐14 labeled paldimycin trisodium salt was prepared by addition of N‐acetyl‐L‐cysteine to [14C]paulomycin, the radioactive antibiotic produced by fermentation of Streptomyces paulus in the presence of L‐methionine labeled with carbon‐14 in the S‐methyl group Carbon‐13 nuclear magnetic resonance (NMR) spectra of paulomycin produced when the fermentation was carried out in the presence of L‐[S‐methyl‐13C]methionine showed that isotope incorporation had occurred specifically at the methoxy group of ring C, i.e., the 2‐deoxy sugar portion of paulomycin. With sustained slow feed of labeled precursors during the optimum antibiotic production period, carbon‐14 isotope yields of up to 17.5% with specific activity of up to 11.4 μCi per milligram of paulomycin, and carbon‐13 isotope yields of up to 24% with 17‐fold isotope enrichment over natural abundance, were achieved.
The synthesis of deuterium‐labelled 2‐bromoethanol, acrylonitrile, acrylamide, 2‐aminoethanol, 2‐bromoethylamine hydrobromide and 1‐bromo‐2‐chloroethane
Authors: Bird Ian , Farmer Peter B.
Published: October 2006

Methods are described for the synthesis of C [2H4]‐2‐bromo‐ethanol, [1‐2H2]‐2‐bromoethanol, [2‐2H2]‐2‐bromoethanol, [2H3]‐acrylonitrile and [2H3]‐acrylamide from 2‐benzyloxyacetic acid. In the synthesis of [1‐2H2]‐1‐bromo‐2‐chloroethane and [2‐2H2]‐1‐bromo‐2‐chloroethane from chloroacetonitrile via deuterated 2‐aminoethanol and [1‐2H2]‐2‐bromoethylamine hydrobromide or [2‐2H2]‐2‐bromoethylamine hydrobromide some randomisation of the halogens occurred, and difficulties were experienced in preparing isotopically pure products.
Preparation du (+)‐Cis‐isobutyl‐3 dimethyl‐2,2 cyclopropane carboxylate de benzyl‐5 furylmethyle‐3 tritie, derive du pyrethrinoide (+)‐cismethrine
Authors: Thang Do‐cao‐ , Nam Nguyen‐hoang‐ , Hoellinger H.
Published: October 2006

The catalytic reduction of (+)‐cismethrin 1, a synthetic pyrethroid, with tritium gas in various solvents and in presence of different catalysts was studied. The best result was obtained with 5% Pd‐ BaSO4 catalyst in methanol giving rise to 3H‐5‐benzyl‐3‐furylmethyl (+)‐cis‐3‐isobutyl‐2,2‐dimethylcylopropane carboxylate 2 with a specific activity of 98 Ci. mmol−1 (3626 GBq. mmol−1). The incorporation of tritium was verified by H‐NMR and MS analyses.
Tritium labelling of cholest‐4‐en‐3‐one by catalytic debromination of 2,2‐6B‐tribromo‐cholest‐4‐en‐3‐one
Authors: Römer J
Published: October 2006

The catalytic debromination of 2,2,6ß‐tribromo‐cholest‐4‐en‐3‐one with tritium gas (T2) yields tritium‐labelled cholest‐4‐en‐3‐one of high specific activity. The most favourable reaction parameters are reported. Using tritium‐hydrogen (TH) gas mixtures the labelling reactions are accompanied by three kinetic isotope effects the importance of which is discussed.