bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of [Imidazolidinone‐2‐14C]Go 10213 (satranidazole, cibemid®)
Authors: Anjaneyulu B. , Nagarajan K. 
Published: October 2006

AbstractFor additional pharmacokinetic and metabolism studies in laboratory animals and in humans, Go 10213 was labelled with carbon‐14 located on the carbonyl carbon atom of the ethyleneurea ring (Ring B) of the molecule. [imidazolidinone‐2‐14C]Go 10213 having a specific activity of 6.06 μCi/mg (1.75 mCi/mmol) was synthesised starting with [14C]ethyleneurea in two steps.
Synthesis of 7‐chloro‐1,3,‐dihydro‐3‐hydroxy‐1‐methyl‐5‐phenyl‐2h‐1,4‐benzodiazepin‐2‐one‐2‐14c (2‐14C‐temazepam)
Authors: Dain Jeremy G. 
Published: October 2006

AbstractTemazepam‐2‐14C, 7‐Chloro‐1,3,‐dihydro‐3‐hydroxy‐1‐methyl‐5‐phenyl‐2H‐1,4‐benzodiazepin‐2‐one‐2‐14C, was prepared in a five‐step synthesis. Chloroacetic‐1‐14C acid was converted to the acid chloride with thionyl chloride. The acid chloride was allowed to react with 2‐methylamino‐5‐chloro‐benzophenone to form the amide. The amide was reacted with hydroxylamine and directly cyclized to the benzodiazepine N‐oxide which was converted to the acetate with acetic anhydride. The acetate was hydrolyzed with concentrated sulfuric acid to give the final product (3.8% radiochemical yield at 52. mCi/mmol). This procedure provides temazepam with the radiolabel in a metabolically stable position.
Synthesis of methanol tritiated in the methyl group only
Authors: Dass Desmond V. , Dempsey Victor J. , Martin R. Wayne , Odell Allan L. 
Published: October 2006

AbstractMethanol has been labelled with tritium in the methyl group, and the position of the label confirmed using Tritium N.M.R. spectrometry. The methanol was prepared by reacting tritium, hydrogen and carbon dioxide over a copper/zinc/chromium catalyst at a total pressure of 500 psi. Water was removed by microdistillation followed by preparative G.L.C. These procedures also removed tritium from the hydroxyl group of the methanol.
Synthesis of 2‐amino‐1,5‐dihydro‐1‐(methyl‐13C)‐4H‐imidazol‐4‐one‐5‐13C (creatinine‐13C2)
Authors: Cohen A. , Hertz H. H. , Schaffer R. , Welch M. M. , White E. 
Published: October 2006

Abstract2‐Amino‐1,5‐dihydro‐1‐(methyl‐13c)‐4h‐imidazol‐4‐one‐5‐13c (creatinine‐13C2) (8) is synthesized as follows. Glycine‐2‐13c (1) is tosylated; the product (2) is treated with iodomethane‐13C; and the resultant doubly‐labeled product (3) is detosylated to yield sarcosine‐13C2 (4). Creatine‐13C2 (7) is obtained by treating 4 with 2‐methylisothiourea monohydriodide (5) or cyanamide (6). Dehydration of 7 under vacuum sublimation conditions gives 8.
New realistic approach of the kinetics in fast labelling procedures
Authors: Mertens J. , Callaerts A. , Vanryckeghem W. 
Published: October 2006

AbstractA real kinetic approach of fast labelling reactions is obtained by introducing a corrected reaction time τ which takes into account the temperature rise process of the reaction solution. τ is obtained by transformation of transient temperature data to isothermal conditions at a preset temperature. Experimental data obtained for 123I‐radioiodination of ortho‐iodohippuric acid fit completely with the theory.
The preparation and characterization of [3H] histamine.2HCl at high specific activity1
Authors: Filer Crist N. , Ahern David G. 
Published: October 2006

Abstract[3H] Histamine.2HCl will continue to play a key role in establishing the neurotransmitter status of histamine.2HCl. To more consistently achieve high specific activity in the preparation of the radioligand and incorporate as much tritium into the stable side chain positions as possible, we explored the use of alternative tritiation precursors. Imidazole 4‐acetonitrile (5) and 2,5‐diiodoimidazole‐4‐acetonitrile (6) were catalytically reduced with tritium gas and the radiolabeling specificity of the resulting [3H] histamine.2HCl produced was confirmed by 3H NMR.
A new synthesis and NMR‐spectroscopy of [15N‐, 5,4‐13C]‐aminolevulinic acid
Authors: Nitsche Bernhard , Köst Hans‐Peter , Cmiel Edmund , Schneider Siegfried 
Published: October 2006

AbstractA new synthesis of [15N‐, 5,4‐ 13C]‐aminolevulinic acid (ALA) starting from amorphous 13C is described. NMR‐spectroscopic data (1H, 13C, 15N) of the product are presented.
Possible drugs labelled with 14C.IV.1 synthesis of D‐pheylalaninyl‐prolyl‐arginine aldehyde labelled in the guanidino group
Authors: Koltai E. , Bajusz S. , Széll E. , Zólyomi G. 
Published: October 2006

Abstractα‐tert‐Butyloxycarbonyl‐ω‐benzyloxycarbonyl‐[guanido‐14C]arginine was prepared by reacting α‐tert‐butyloxycarbonyl‐ornithine with N‐benzyloxy‐carbonyl‐S‐methyl‐[14C]isothiourea, and it was transformed to D‐phenylalaninyl‐prolyl‐[guanido‐14C]arginine aldehyde, via ω‐benzyloxycarbonyl‐[guanido‐14C]‐arginine lactam.
Preparation of [22,23‐3H2]‐dihydroavermectin B1a of high specific activity
Authors: Toth G. , Kardos J. , Fodor A. , Sirokman F. 
Published: October 2006

Abstract[22,23‐3H2]‐Dihydroavermectin B1a of 2.13 TBq/mmo1 (57.7 Ci/mmol) specific activity was derived from avermectin B1a by selective tritiation using Wilkinson's homogeneous catalyst. Data on binding affinity and nematotoxic activity of the title compound are reported.
Synthesis of specifically labeled (S)‐nicotine‐5‐3H and (S)‐cotinine‐5‐3H BY carrier free tritiolysis of the corresponding 5‐bromo derivatives
Authors: Shigenaga Mark K. , Jacob Peyton , Trevor Anthony , Castagnoli Neal , Benowitz Neal 
Published: October 2006

AbstractThe synthesis of high specific activity tritium labeled (S)‐nicotine and (S)‐cotinine has been achieved. (S)‐5‐Bromonornicotine of high enantiomeric purity was converted to the corresponding (S)‐5‐bromonicotine by reductive amination with formaldehyde and sodium borohydride. Tritiolysis of this intermediate with carrier free tritium in the presence of triethylamine using 10% Pd/C catalyst provided (S)‐nicotine‐5‐ H with a specific activity of 32 Ci/mmol in ethanol solvent and 28 Ci/mmol in tetrahydrofuran solvent. Similarly, tritiation of (S)‐5‐bromocotinine, obtained by oxidation of (S)‐5‐bromocotinine, obtained by oxidation of (S)‐5‐bromonicotine with bromine followed by reduction of the intermediate (S)‐3′, 3′, 5‐tribromonicotine with zinc dust, yielded the corresponding (S)‐cotinine‐5‐ H (22.8 Ci/mmol). All reactions proceeded in good to excellent yields.
Catalytic tritiation and 3H NMR spectroscopy of complex organic mixtures ‐ application to engine oil basestocks
Authors: Carroll Leonor , Jones John R. , Shore Philip R. 
Published: October 2006

AbstractSeveral catalytic hydrogen‐tritium exchange procedures have been investigated in order to accomplish uniform and random incorporation of tritium into the diverse organic components present in two engine oil basestocks. The most successful procedure involved the use of Raney nickel and tritiated water at elevated temperatures. Comparative proton and tritium nuclear magnetic resonance spectroscopy shows that the incorporated tritium was representative of the organic components present in the basestocks. Comparative gas‐ and radio‐gas chromatography studies provided supplementary information. These investigations demonstrate that engine oils can be satisfactorily labelled with tritium for studies of engine oil consumption.
Synthesis of 3H‐labelled levamisole
Authors: Thijssen J. J. A. , Knaeps A. A. , Verluyten W. W. M. , Heykants J. J. P. , Janssen C. C. M. 
Published: October 2006

AbstractLevamisole, the levo isomer of tetramisole, is a potent anthelmintic also showing immunotropic properties. Renewed interest in the latter domain necessitated the synthesis of specifically 3H‐labelled levamisole of high specific activity.Racemic 1‐(2‐bromophenyl)‐1,2‐ethane diamine dihydrochloride (V) was obtained via bromination of 1‐(2‐bromophenyl)ethanone (I), followed by reaction with 2,5‐pyrrolidinedione, Leuckart amination and hydrolysis. The racemate was then resolved by successive salt formation with (S)‐(‐) and (R)‐(+) tartaric acid. The liberated (S)‐(+)‐base of VI was dehalogerated with approximately 30 Ci of tritium gas and immediately ring‐closed with carbon disulfide to VIII. The HPLC‐purified material was finally cyclized with 1,2‐dibromo ethane to (S)‐(‐)‐2,3,5,6‐tetrahydro‐6‐[2‐T]phenyl‐imidazo‐(2,1‐b)‐thiazole IX and the isomerically ringclosed (S)‐2,3,5,6‐tetrahydro‐5‐[2‐T] phenyl‐imidazo‐(2,1‐b)‐thiazole X, of which levamisole IX was isolated via HPLC. The radiochemical yield over the cyclization steps was 28.2 %, the specific activity was 10.82 Ci/mmol, and the product was 99.9 % HPLC pure.
Synthesis of 14C‐labeled benzofurano[2,3‐b] benzopyran‐6‐one and its 4‐hydroxycoumarin derivative
Authors: Chubachi Mitsuo , Kawano Eiko 
Published: October 2006

Abstract2‐Isopropyl‐8,9‐dimethoxy‐benzofurano [2,3‐b]furo[2,3‐h] [1] [11‐14C]benzopyran‐6‐one (IVb) and 3‐(2‐hydroxy‐4,5‐dimethoxyphenyl)‐4‐hydroxy‐5′‐isopropylfurano[2′,3′:7,8] [2‐14C]coumarin(Vb) were prepared from isorotenone (Ib) for use in metabolic and other studies. Deoxybenzoin derivative (IIb), obtained from isorotenone, was reacted with ethyl [14C] formate in the presence of sodium to give the corresponding [2‐14C]‐2′‐hydroxyisoflavone (IIIb), which was transformed into the 14C‐labeled benzofurano [2,3‐b]furo[2,3‐h]benzopyran‐6‐one compound (IVb) by the subsequent oxidative cyclization with selenium dioxide. Hydrolysis of compound IVb in alkaline media gave 14C‐labeled 4‐hydroxycoumarin (Vb).
Tritium labelled compounds of high specific activity III. Trifluoperazine
Authors: Zólyomi Gábor 
Published: October 2006

AbstractTrifluoperazine labelled with tritium at a specific activity of 3.15 TBq/mmol was prepared by methylation of N‐desmethyltrifluoperazine with no‐carrier added [3H]methyl iodide. An improved method for preparation of the precursor is also described.
Synthesis of 7‐(4′‐fluoro‐3,3′,5‐trimethyl[1,1′‐biphenyl]‐2‐YL)‐3‐hydroxy‐5‐OXO‐5‐13C‐heptanoic acid and trans‐6‐[2‐(4′‐fluoro −3,3′,5‐trimethyl[1,1′‐biphenyl]‐2‐YL)ethyl]‐3,4,5,6‐tetrahydro‐6‐13C‐4‐hydroxy‐2H‐pyran‐2‐one
Authors: Stokker Gerald E. 
Published: October 2006

AbstractThe title compounds are potent HMG‐CoA reductase inhibitors. A 13C‐label was introduced into these compounds to permit probing of their interaction with HMG‐CoA reductase by 13C NMR techniques in the presence and absence of added NADPH.
Synthesis of [3H] tyr‐D‐thr‐gly‐phe(pN3)‐leu‐thr an irreversible photoaffinity probe for the opioid δ receptors
Authors: Gacel G. , Fellion E. , Roques B. B. , Genet R. , Morgat J. J. , Fromageot P. 
Published: October 2006

AbstractIn a previous work, the synthesis of [3H] Tyr‐D‐Thr‐Gly‐Phe‐Leu‐Thr (DTLET), a highly selective probe for δ opioid receptors has been described. More recently, Az‐DTLET (Tyr‐D‐Thr‐Gly‐Phe (pN3)‐Leu‐Thr) has been shown to be a specific and irreversible photoaffinity ligand for δ opioid sites. In the present paper, we reported the synthesis of the 3,5 dibromotyrosyl 4′‐amino‐3′,5′ diiodophenylalanyl precursor of [3H] Az‐DTLET. Reductive tritiation by exchange with 3H2 followed by the introduction of the azido group leads to the labelled azido analog of enkephalin with specific activity of 50 Ci/mmole. This compound is now used to characterize the subunits of opioid δ receptors and to visualize these targets in the brain by electron microscopy.
Multi‐13 C‐labelled inhibitors of tubulin assembly: 5‐substituted methyl N‐(1H‐benzimidazol‐2‐YL)carbamates
Authors: Cheung H. H. Andrew , Chau Diem Dieu , Lacey Ernest 
Published: October 2006

AbstractEight methyl N‐(1H‐benzimidazol‐2‐yl) carbamates with various 5‐substituents were synthesized, each 13C‐enriched at carbon 2, and the carbonyl and methoxy carbons. Five were prepared by cyclization involving the appropriate 4‐substituted 1,2‐diaminobenzene (C6H5CO‐, CH3CH2CH2O‐, CH3CH2S‐, C6H5S‐ and CH3CH2CH2‐), and methyl‐13C N‐[imino(methylthio) methyl‐13C]carbamate‐13C or methyl N, N'‐bis(methoxy‐13C‐carbonyl‐13C)carbamimidothionate‐ 13C. The latter were prepared from commercially available 13C‐enriched (91‐92 atom %) carbon tetrachloride, methanol, and thiourea. The remaining three (5‐substituents: C6H5CH(OH)‐, C6H5SO‐ and CH3CH2CH2SO‐) were prepared by side‐chain reduction or oxidation. The 1H‐ and 13C‐NMR, and the methane CI mass spectral data of the products and intermediates are presented.
Folate analogues: 27. syntheses of 14carbon‐labeled 10‐deazaaminopterin and 10‐ethyl‐10‐deazaaminopterin
Authors: Nair M. M. , Nanavati Nitin T. 
Published: October 2006

Abstract10‐Deazaaminopterin (1) and 10‐Ethyl‐10‐deazaaminopterin (2) labeled uniformly with 14C at the glutamate moiety were prepared by the following procedure. Uniformly labeled L‐glutamic acid was converted to its dimethyl ester (3). 4‐Amino‐4‐deoxy‐10‐deazapteroic acid (4) and 4‐amino‐4‐deoxy‐10‐ethyl‐10‐deazapteroic acid (5) were converted to their respective mixed anhydrides 6 and 7 with isobutylchloroformate. Reaction of 6 and 7 with labeled dimethyl‐L‐glutamate gave dimethyl‐10‐deazaaminopterin (8) and dimethyl 10‐ethyl‐10‐deazaaminopterin (9) respectively, which on mild alkaline hydrolysis gave the target compounds 1 and 2 in 22‐25% yield, based on the amount of radiolabeled glutamic acid used.
Synthesis of (R)‐(+)‐3H‐etomidate
Authors: Janssen Cor G. M. , Thijssen Jos B. A. , Verluyten Willy L. M. , Heykants Jozef J. P. 
Published: October 2006

AbstractEtomidate, (R)‐(+)‐ethyl‐1‐(1‐phenylethyl)‐1H‐imidazole‐5‐carboxylate, is a short‐acting hypnotic. A new synthesis, featuring optical resolution on a non‐radioactive precursor and introduction of the tritium label by reductive dehalogenation, is described.The title compound was obtained at a specific activity of 3.77. Ci/mmol and a 99.9 % HPLC purity.
Synthesis of 1,2,3,4‐tetrahydrocarbazole‐9a‐13C and carbazole‐9a‐13C
Authors: Pickering R. E. , Wysocki M. A. , Eisenbraun E. J. , Pell R. J. , Gearhart H. L. , Hamming M. C. 
Published: October 2006

AbstractThe synthesis of 1,2,3,4‐tetrahydrocarbazole‐9a‐13C and carbazole‐9a‐13C via cyclohexanone‐1‐13C, prepared in turn from carbon dioxide‐13C and 1,5‐pentanedimagnesium bromide is described.
Direct deuterium labelling of xanthone with the lithium salt of 1,3‐diaminopropane‐N, N, N',N'‐d4
Authors: Abrams Suzanne R. 
Published: October 2006

AbstractA direct method for selective deuteration of xanthone 1 employing the lithium salt of 1,3‐diaminopropane‐N, N, N',N'‐d4 is described. Dibenzofuran is also found to be deuterated selectively under these conditions.
Radioactively labelled epoxides. part V. Tritium labelled K‐region oxides and trans‐dihydrodiols of pyrene, benzo[a]pyrene and dibenz[a, h]anthracene
Authors: Setiabudi Frans , Oesch Franz , Platt Karl L. 
Published: October 2006

AbstractTritium labelled K‐region oxides of pyrene, benzo[a]pyrene and dibenz[a,h]anthracene have been prepared by cyclization of the corresponding trans‐dihydrodiols which were obtained by reduction of K‐region quinones with sodium borotritide in the presence of oxygen. This synthetic pathway not only yields two metabolically important radioactively labelled derivatives of polycyclic aromatic hydrocarbons in a simple and efficient manner, but also requires a rather inexpensive source of tritium.
Synthesis of [4,4,4‐2H3]butanoic acid
Authors: Visser Frans R. 
Published: October 2006

AbstractThe synthesis of [4,4,4‐2H3]butanoic acid with 10% yield from deuterated acetic acid is described. The structure is confirmed by n.m.r. and mass spectroscopy and the percentage of labelling is established as >98.5% [2H3]butanoic acid.
Synthesis of [14C]amiflamine ‐ an MAO‐A inhibitor
Authors: Sahlberg Christer , Gawell Lars 
Published: October 2006

AbstractAmiflamine ( (S)‐(+)‐2‐(4‐dimethylamino‐2‐methylphenyl)‐1‐methylethylamine) is a potent, selective, and reversible MAO‐A inhibitor. Carbon‐14 labelled amiflamine (8) with a specific activity of 8.1 mCi/mmol was prepared. The key‐step in the synthesis is a Cu(I)‐catalyzed reaction of an organometallic derivative obtained from compound (6) with 14CH3I. Also described is the synthesis of the optically active compound (6).
Synthesis of [2‐14C]‐1‐(2‐deoxy‐2‐fluoro‐β‐D‐arabinofuranosyl)‐5‐fluoro(chloro)uracil
Authors: Misra Hemant K. , Wiebe Leonard I. , Knaus Edward E. 
Published: October 2006

AbstractThe reaction of [2‐14C]‐2,4‐bis‐O‐(trimethylsilyl)uracil (2) with 3‐O‐acetyl‐5‐O‐benzoyl‐2‐deoxy‐2‐fluro‐α‐D‐arabinofuranosyl bromide (3) yielded the 3‐O‐acetyl‐5‐O‐benzoyl nucleoside 4 which was hydrolyzed with methanolic ammonia to afford [2‐14C]‐1‐(2‐deoxy‐2‐fluro‐β‐D‐arabinofuranosyl)uracil (5) in 55% radiochemical yield with a specific activity of 2 mCi/mmol (74 MBq/mmol). The reaction of 5 with molecular fluorine and chlorine in glacial acetic acid at 25°C afforded the 5‐fluoro‐6a and 5‐chloro‐6b analogues of [2‐14C]‐1‐(2‐deoxy‐2‐fluoro‐β‐D‐arabinofuranosyl)uracil in 85.6 and 87.9% isolated radiochemical yield, respectively. Similar radiochemical yields were obtained when [2‐14C]uracil having a specific activity of 12 mCi/mmol (444 MBq/mmol) was utilized.
The Synthesis of 8‐β‐[(Methylsulfinyl‐[18O])‐methyl]‐6‐propylergoline
Authors: Wheeler William J. 
Published: October 2006

AbstractThe synthesis of 18O‐labeled 8‐β‐[(methylsulfinyl)‐methyl]‐6‐propyl‐ergoline (pergolide‐[18O]‐sulfoxide) of undetermined stereochemistry by the reaction of 8‐β‐(methylthiomethyl)‐6‐propyl‐ergoline (pergolide) with bis‐(4‐methoxyphenyl)‐selen‐[18O]‐oxide in acetic acid is described. Although the yields were low and the incorporation of 18O was not high, this procedure represents a convenient method for the preparation of 18O‐labeled sulfoxides of pergolide and other sulfides present in compounds for which the usual methods are inappropriate.
Modified and improved method for synthesis of p‐halogenated‐N‐isopropylamphetamine leading to synthesis of “no carrier added” I‐131 iodoamphetamine
Authors: Najafi A. 
Published: October 2006

AbstractI‐123 labeled N‐isopropyl‐p‐iodoamphetamine (IMP) has been shown to be an important and useful radiopharmaceutical for measurement of cerebral blood flow (1–4). Since substituted amphetamines have a strong pharmacological activity, the synthesis of “No Carrier Added” (NCA) labeled IMP would be desirable (5). In this paper we would like to report a modified and improved method for the synthesis of para‐halogenated‐N‐isopropylamphetamine and the preparation of NCA I‐131 IMP. This procedure involves a labeling reaction using I‐131 sodium iodide and para‐bromo‐N‐isopropyl amphetamine (BrMP) followed by HPLC separation of I‐131 IMP and BrMP using reverse phase chromatography.
Synthesis of double carbon‐14 labeled CI‐9371 and CI‐942, potential new anticancer drugs
Authors: Hicks James L. , Huang C. C. , Showalter H. D. Hollis 
Published: October 2006

AbstractCI‐937 and CI‐942, compounds which show potent anticancer activity, were synthesized with double labeled high specific activity carbon‐14. The key intermdiate in the synthesis, 3,6‐dichloro‐[dicarbonyl‐14C2]phthalic anhydride was made by treating 2‐bromo‐1,4‐dichlorobenzene with n‐butyllithium and 14CO2 to give 2,5‐dichloro[carboxy‐14C]benzoic acid, which was converted to its diethylamide. Ortho‐directed lithiation followed by a second carboxylation produced the ortho acid‐amide. Hydrolysis and dehydration generated the anhydride. Friedel‐Crafts acylation of the anhydride with 1,4‐benzenediol gave 1,4‐dichloro‐5,8‐dihydroxy[9,10‐14C2]‐9,10‐anthracenedione. Protection and hydrazination gave a chloroanthrapyrazole intermediate which was converted into [14C2]CI‐937 or [14C2]CI‐942 in two steps. The specific activities of the final compounds were 196 μCi/mg and 182 μCi/mg respectively.
A simple, efficient synthesis of 3′‐D3‐mevalonic acid
Authors: Hawkins Douglas R. , Calvin Melvin 
Published: October 2006

Abstract3′‐D3‐Mevalonic acid was required to study triterpenoid biosynthesis. It was synthesized by a simple route in a 24% yield from D3‐acetic acid‐D. The product was characterized as the crystalline salt: N, N'‐dibenzylethylenediammonium bis‐(3,5‐dihydroxy‐3‐(D3‐methyl)‐pentanoate) and was shown by mass spectroscopy and 1H‐NMR to be essentially 100 atom% deuterium labelled.
Synthesis of tritium‐labeled (3)‐O‐(3‐hydroxypropyl)‐17α‐estradiol chromium tricarbonyl: The first radioactive transition metal carbonyl steroid hormone
Authors: Top Siden , Vessieres Anne , Jaouen Gérard 
Published: October 2006

Abstract3‐O‐(3‐hydroxypropyl)‐17β‐estradiol chromium tricarbonyl 1 has been labeled in the 17α position with deuterium or tritium. These complexes were prepared by reduction of the corresponding estrone by NaBD4 or NaB[3H]4. The radioactive hormone was obtained in a solid state with a specific activity of 4.1 Ci/mmole, which is sufficiently high for hormone receptor binding studies.
Preparation of E‐ and Z‐5‐deuterioadamantan‐2‐ol
Authors: Lin Man‐Hua , Le Noble W. J. 
Published: October 2006

AbstractThe title synthesis can readily be carried out on a 50 mg scale or more, starting with the 54/46 mixture of E‐ and Z‐5‐bromoalcohols obtained from the sodium borohydride reduction of the ketone. The key feature on which the synthesis dependes is the fact that the Z‐trimethylsilyl bromoether is reduced by zinc borohydride (and ‐deuteride) in benzene much faster than the E‐ epimer.
Synthesis of specifically labelled L‐phenylalanines using phenylalanine ammonia lyase activity
Authors: Hädener A. , Tamm Ch. 
Published: October 2006

AbstractSpecifically labelled L‐phenylalanines have been prepared using a variety of classical synthetic methods in combination with phenylalanine ammonia lyase (PAL) enzyme activity of the yeast Rhodosporidium toruloides ATCC 10788 or Rhodotorula glutinis IFO 0559, respectively. Thus, L‐[2‐2H]phenyl‐[2‐2H]alanine (5) was formed from (E)‐[2,2′‐2H2]cinnamic acid and ammonia in 46% yield, whereas L‐phenyl‐[2‐13C,15N]alanine (9) was obtained from (E)‐[2‐13C]cinnamic acid in 45% overall yield using an 8.3‐fold excess of 15NH4Cl and repeating the reaction after recovery of unchanged labelled material. Generally, labelled cinnamic acids were recovered in pure form from the reaction mixture, with a loss of 6‐8%. Likewise, unchanged 15NH3 was reisolated as 15NH4Cl after steam distillation with overall losses of less than 4%. Labelled cinnamic acids were prepared by Knoevenagel condensations between appropriately labelled benzaldehydes and malonic acids. [2‐2H]Benzaldehyde was obtained from 2‐bromotoluene by decomposition of the corresponding Grignard reagent with 2H2O and subsequent oxidation. Since simple molecules, most of them commercially available in labelled form or otherwise easily accessible, may serve as starting material, and due to its defined stereochemistry, the reaction catalyzed by PAL opens a short and attractive route to specifically labelled L‐phenylalanines.
Synthesis of 1‐[(1,4‐benzodioxan‐2‐ylmethyl)amino]‐3‐(3‐pyridazinon‐2‐YL)‐[3‐14C]propane hydrochloride (gyki‐12743), a new antihypertensive agent
Authors: Birkás‐Faigl E. , Zólyomi G. , Makk N. , Kasztreiner E. 
Published: October 2006

AbstractA new antihypertensive agent, GYKI‐12743, has been labelled with carbon‐14 via a six‐step synthesis. The label was introduced by chain elongation of an appropriate precursor using potassium [14C]cyanide as radioactive starting material. A satisfactory overall yield, 44.7 %, relative to KCN was achieved.
Synthèse et distribution tissulaire chez le rat du Phénylacétate de Diéthylamino‐2 éthyle marqué par 14C
Authors: Moreau M. M. , Michelot J. , Labarre P. , Parry D. , Veyre A. 
Published: October 2006

Abstract2‐Diethylaminoethyl phenylacetate was labelled by 14C in two positions:

‐ on the carboxylic group by means of 14C‐phenylacetic acid.
‐ on the aminoethanol part using 14C ethanolamine as intermediate.

Biodistribution studies were performed in rats for the two labellings after i.v. administration of the compound.