bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of a radiotracer for studying dopamine uptake sites in vivo using PET: 2β‐carbomethoxy‐3β‐(4‐fluorophenyl)‐[N‐11C‐methyl]tropane ([11C]CFT or [11C]WIN‐35,428)
Authors: Dannals Robert F. , Neumeyer John L. , Milius Richard A. , Ravert Hayden T. , Wilson Alan A. , Wagner Henry N. 
Published: October 2006

Abstract2β‐Carbomethoxy‐3β‐(4‐fluorophenyl)‐[N‐11C‐methyl]tropane, a potent inhibitor of dopamine transport, was prepared by N‐methylation of the appropriate nor‐methyl precursor in DMF with [11C]iodomethane. After derivatization of unreacted precursor with a long chain acyl halide, the radiotracer was purified using reversed phase semipreparative HPLC. The average specific activity was 3065 mCi/μmole (calculated at the end‐of‐synthesis; EOS). The average time of synthesis including formulation was approximately 21 minutes.
Preparation of 15N‐13C‐fulminic acid
Authors: Wilmes Rolf , Winnewisser Manfred 
Published: October 2006

AbstractThe precursor for the title compound was prepared in a three‐step synthesis. The 13C‐label was incorporated in the first step employing 2‐13C‐ethyl acetate and the 15N‐label in the last step, using 15N‐sodium nitrite. Upon pyrolysis the precursor forms three fragments, one of them being the title compound.
Probing protein structure and dynamics by tritium NMR
Authors: O'Connell T. M. , Williams P. G. , Gerig J. T. 
Published: October 2006

AbstractTritium nmr spectroscopy of specifically tritiated tosylchymotrypsin has been used to examine the properties of the tosyl group in this protein. The unavoidable presence of several tritiated isotopomers complicates analysis of experiments and extensive computer simulations of relaxation behavior of tritiated species present were used in conjunction with models developed from crystallographic results to interpret the observations made. These analyses suggest that the tosyl group of tosylchymotrypsin at pH 4 is highly mobile in solution and occupies the lacation in the protein that is observed in the crystalline state only about 50% of the time.
The synthesis of carbon‐14 labeled pravastatin
Authors: Wallace M. A. , Dean D. C. , Ellsworth R. L. , Melillo D. G. , Marks T. , White R. F. 
Published: October 2006

AbstractAs asymmetric route to [14C]β‐hydroxycompactin 1 bearing the (S)‐2‐methyl‐[1‐14C]butanoate side chain has been developed. Methylation of [N‐[1‐14C]butyryl‐4‐(S)‐phenylmethyl‐2‐oxazolidinone 4 afforded a 95:5 mixture of diastereomeric [N‐(S,R)‐2‐methyl‐[1‐14C]butyryl]‐4‐(S)‐phenylmethyl‐2‐oxazolidinones 5,6 which were separated by preparative HPLC. Oxidative cleavage of 5 afforded optically pure (S)‐2‐methyl‐[1‐14C]butanoic acid. Acylation of alcohol 9 with optically pure (S)‐2‐methyl‐[1]14C]butyryl chloride afforded ester 10. Removal of the silyl either produced diastereomerically pure compactin 11. Hydroxylation was carried out by biotransformation with Mucor hiemelus to afford diastereomerically pure [[1‐14C]butanoate]β‐hydroxycompactin, [14C]Pravastatin 1.
Synthesis of [18F]‐(S)‐fluoxetine: A selective serotonine uptake inhibitor
Authors: Hammadi Akli , Crouzel Christian 
Published: October 2006

AbstractThe (S)‐N‐methyl‐γ‐[4‐(trifluoromethyl)phenoxy]benzenepropanamine, an antidepressant with potential applications in the treatment of other illnesses was labelled with fluorine‐18 for Positron Emission Tomography studies. The synthesis was accomplished from the [18F]‐4‐chlorobenzotrifluoride where [18F]‐(S)‐Fluoxetine was obtained with a radiochemical yield of 9–10% (decay corrected) and a specific radioactivity of 100–150 mCi/μmol (3.70–5.55 GBq/μmol) in a total synthesis time of 150 min. A facile isotopic exchange reaction was desmonstrated; it is expected to reduce the specific activity of the final [18F]‐product. The experimental parameters play an important role, which is discussed.
Facile synthesis of (4S)‐(−)‐[9‐3H]limonene
Authors: Hiraga Yoshikazu , Danjo Hiroshi , Ito Takatoshi , Suga Takayuki 
Published: October 2006

Abstract(4S)‐[9‐3H]‐1‐Methyl‐4‐(1′‐methylethenyl)cyclohexene ((4S)‐(−)‐[9‐3H]limonene) was synthesized from (1′S,2RS)‐2‐(4′‐methylcyclohex‐3′‐enyl)porpanal ((4S,8RS)‐(−)‐1‐p‐menthen‐9‐al) via a convenient route in a high yield with improved enantiomeric purity.
14C‐labelling of NNC 756, a new dopamine D1 antagonist
Authors: Foged Christian , Hansen Louis B. , Halldin Christer 
Published: October 2006

AbstractA 14C labelled form of (+)‐8‐chloro‐5‐(2,3‐dihydrobenzofuran‐7‐yl)‐7‐hydroxy‐3‐methyl‐2,3,4,5‐tetrahydro‐1H‐3‐benzazepine (NNC 756) (8) was synthesized in 7 steps, including resolvation of the active (+)‐form, starting from [14C]methyl iodide and 7‐benzofurancarbaldehyde. The overall radiochemical yield was 11%. The radiochemical purity of [4‐14C]NNC 756 was higher than 98% with a specific radioactivity of 24 mCi/mmol.
The synthesis of [14C]‐3S,4R‐4‐(4‐fluorophenyl)‐3‐(3,4‐methylenedioxyphenoxymethyl)piperidine hydrochloride (BRL 29060A), and mechanistic studies using carbon‐13 labelling
Authors: Willcocks K. , Barnes R. D. , Rustidge D. C. , Tidy D. J. D. 
Published: October 2006

AbstractParoxetine, BRL 29060A 1 has been labelled with both carbon‐14 and carbon‐13. Hydroxymethylation of 4‐(4‐fluorophenyl)‐1‐methyl‐1,2,5,6‐tetrahydropyridine, using [14C]formaldehyde, produced an enantiomeric mixture of products which was taken without separation through a multistage sequence. Resolution of the mixture of stereoisomers at the penultimate step gave [14C]BRL 29060A with the required configuration. The overall radiochemical yield was 8%. At some stage in this process, as shown by C‐13 labelling studies, scrambling of the label took place to give BRL 29060A with the majority of the label in the C‐2 position of the piperidine ring and the remainder at the expected 7‐methylene position. Further investigations of this route using carbon‐13 as the label are described. When sesamol, (3,4‐methylenedioxyphenol) was reacted with the O‐benzene sulphonate of (±)‐cis‐4‐(4‐fluorophenyl)‐3‐(hydroxy[13C]methyl)‐l‐methylpiperidine, an inversion of configuration resulted via the previously described 1‐aza[3.1.1]bicycloheptane ring system. It is also shown that the corresponding (±)‐trans‐substituted piperidine, under similar conditions, does not undergo this inversion.
A method for synthesis of 14C‐labelled styrene
Authors: Majcherczyk Andrzej , Braun‐Lüllemann Annette , Hüttermann Aloys 
Published: October 2006

AbstractSide‐chain and ring 14C‐labelled styrene were synthesised from labelled benzene and acetaldehyde via bromobenzene, Grignard‐reagent and 1‐phenylethanol. Uniformly 14C‐labelled styrene can be also prepared using this method. By‐products were identified and the purity of products was determed by GC‐MS.
Synthesis of (2,3‐13C2) erucic acid
Authors: Olsen Julie A. , Bukata Pablo A. 
Published: October 2006

AbstractThe synthesis of (2,3‐13C2) erucic acid, for use in metabolic studies, is reported. The synthesis employs a repeated 3 step reaction sequence using 13C labeled triethylphosphonoacetate to extend C18:1, oleyl alcohol, by 4 carbons. The starting alcohol is first oxidized with PCC and the resulting aldehyde is condensed with triethyl(1‐13C)phosphonoacetate. The product, an α,β unsaturated ester, is reduced with (Ph3PCuH)6 to ethyl eicosenoate. Reduction with LAH gives eicosenoyl alcohol. A repetition of the reaction sequence using triethyl(2‐13C) phosphonoacetate results in ethyl(2,3‐13C2)erucate. The (2,3‐13C2) erucic acid, obtained by hydrolysis with alcoholic KOH, gave 13C NMR signals of δ 24.6 and 34.1 ppm for C‐3 and C‐2 respectively with a J=34.9 Hz. The overall yield was 5.5%.
The synthesis of 4‐2H‐α‐farnesene and 1‐2H‐α‐farnesene
Authors: Fielder Simon , Rowan Daryl D. , Reay Peter F. 
Published: October 2006

Abstractα‐Farnesene deuterated at C1 or C4 was synthesised by regiospecific deuteration of 2‐geranyl‐3‐methylsulpholene (2). Treatment of (2) with butyl lithium in dimethylpropenylurea (DMPU) mediated THF resulted in deprotonation at C2. Quenching with D2O/CH3CO2D gave a mixture of deuterated sulpholenes (43‐68%), predominantly 2‐2H‐2‐geranyl‐3‐methylsulpholene (5), together with bond migrated product (25‐49%). Thermal elimination of sulphur dioxide gave 4‐2H‐α‐farnesene (6)(85%) but with low deuterium incorporation (60%) and poor regiospecificity. Treatment of (2) with butyl lithium in TMEDA mediated THF resulted in deprotonation at C5 with minimal bond migration (1%). Quenching with D2O/CH3CO2D yielded 5‐2H‐2‐geranyl‐3‐methylsulpholene (18)(75%) which on thermolysis gave 1‐2H‐α‐farnesene (19)(86%) with high regiospecificity and improved deuteration (85%). Some mechanistic aspects of the alkylation of 3‐methylsulpholenes are discussed.
Synthesis of [1‐14C]‐2,2‐difluoroethene from [14C]‐formaldehyde
Authors: Ruzicka Jan A. , Qiu Weiming , Baker Max T. , Burton Donald J. 
Published: October 2006

Abstract[1‐14C]‐2,2‐Difluoroethene was synthesized from [14C]‐formaldehyde using a modification of the Wadsworth‐Emmons reaction, via formation of the intermediate (EtO)2P(O)CF214CH2OSiMe3. This highly volatile product was collected in a liquid nitrogen trap at a purity of >97% and specific activity of 0.2 mCi/mmol, with yields of 10 ‐ 15%.
A new synthesis of double labeled [7, 9 ‐13C2] folic acid
Authors: Cowart Marlon , Falzone Christopher J. , Benkovic Stephen J. 
Published: October 2006

AbstractA convenient small scale chemical synthesis of double labeled folic acid with 13C at positions C‐7 and C‐9 is reported. [1,3‐13C2] acetone was converted into folic acid in two steps, with [1, 1, 3]‐trichloroacetone as the labeled intermediate.
A practical approach to the synthesis of 14C‐labeled amino acid and simple peptide
Authors: Ekhato I. Victor , Huang Che C. 
Published: October 2006

AbstractA convenient method for the synthesis of phenylmethyl N‐methyl (carboxy‐14C) glycine hydrochloride (Z) is described. It involves the carboxylation of transmetalated organostannane compound 4 which itself is accessible by established procedure. Success in preparing the labelled amino acid Z enabled us to synthesize target N‐glycyl‐N‐methyl(carboxy‐14C) glycine (10) by conventional coupling protocol.
The synthesis of [14C]SK&F 97426A. A novel bile acid sequestrant
Authors: Lawrie Kenneth W M , Aggarawal Pravina , Saunders David 
Published: October 2006

AbstractSK&F 97426A (10), a 1% crosslinked 11‐trimethylammonioundecylmethacrylate chloride ethylene glycol dimethacrylate co‐polymer bile acid sequestrant, has been prepared in two carbon‐14 labelled forms, namely in the 1‐position of the undecyl side chain and the pendant N‐methyl group. 11‐Bromo[1‐14C]undecyl methacrylate has been prepared and conditions developed for its small scale suspension polymerisation.
Synthesis of 14C‐labeled copolymers for drug delivery studies
Authors: Rhee Sung W. , Reist Elmer J. , Rock Marie T. 
Published: October 2006

Abstract14C‐labeled polyanhydride copolymers [(20:80/1,3‐bis)(p‐carboxyphenoxy)‐propane(CPP):sebacic acid (SA)] (7 and 13) were synthesized according to schemes I and II: 14C‐labeled sebacic acid (2,9‐14C2) (5) and 14C‐labeled CPP 1,3‐bis(p‐carboxyphenoxy)‐propane (labeled at C‐1, C‐3 of the propyl group) (11) were transformed to the corresponding mixed anhydrides (6 and 12) as prepolymers respectively by reaction with acetic anhydride. The labeled mixed anhydride prepolymers (6 and 12) were condensed with unlabeled counter‐prepolymers (12′ and 6′) to give the labeled polyanhydride copolymers (7 and 13). The labeled copolymers (7 and 13) were identified and characterized by gel permeation chromatography (GPC).
Model reactions targeted at the synthesis of carbon‐14 labeled CI‐996, a potent antagonist of angiotensin II receptor (1)
Authors: Ekhato I. Victor , Huang Che C. 
Published: October 2006

AbstractA reaction sequence suitable for the preparation of an analog of 2‐propyl‐1‐[2′‐(1H‐tetrazol‐5‐yl)[1,1′‐biphenyl]‐4‐yl]methyl‐4‐[2‐(trifluoroacetyl)‐1H‐pyrrol‐1‐yl]‐1H‐imidazole‐5‐carboxylic acid, with 14C at the methylene bridge was developed. The would‐be labeled fragment (12) was derived from 4‐iodobenzenemethanol (6), which itself was constructed from 1,4‐dibromobenzene by the application of silicon chemistry. Pd° catalyzed coupling of TBDMS protected 6 and a tetrazole borate 10 gave the compound 12 which upon further transformation to the mesylate 13, N‐alkylated an imidazole to furnish target compound.
Synthesis of methyl [5,6,8,9,14,‐3 H6]‐hepoxilin B3 and its conversion into methyl [5,6,8,9,14,15‐3H6]‐hepoxilin A3
Authors: Demin P. M. , Pivnitsky K. K. , Vasiljeva L. L. , Pace‐Asciak C. R. 
Published: October 2006

AbstractThe selective tritiation of methyl 10(R/S)‐hydroxy‐11(R),12(S)‐epoxyeicosa‐5,8,14‐triynoate into two C10‐epimeric [3H6]‐hepoxilins B3 methyl esters is described. These compounds are subsequently converted into two C8‐epimeric [3H6]‐hepoxilins A3 methyl esters by allylic rearrangement under Mitsunobu conditions via corresponding benzoates.
Synthesis of 14C‐labelled bromocresol green and metacresol purple
Authors: Thourel P. , Vandais A. , Noel J‐P. , Beaucourt J‐P. 
Published: October 2006

Abstract[methyl‐14C]‐Bromocresol green 1 was synthesized from [14C] ‐ methyl iodide in four steps via 3‐[methyl‐14C]‐methylanisole 3, [methyl‐14C]‐metacresol 4 and [methyl‐14C]‐metacresol purple 6. The overall yield of 1 from [14C] methyl iodide was 5.3% and the specific activity 112 mCi/mmol.
Synthesis of 4‐stannylated tamoxifen analogues; useful precursors to radiolabelled idoxifene and aziridinyl 4‐iodotamoxifen
Authors: McCague Raymond , Potter Gerard A. 
Published: October 2006

AbstractThe 4‐stannylated tamoxifen analogues (E)‐1‐[4‐[2‐(N‐pyrrolidino)ethoxy]phenyl]‐1‐[4‐(tributylstannyl)phenyl]‐2‐phenyl‐1‐butene and (E)1‐[4‐[2‐(aziridin‐1‐yl)ethoxy]phenyI]‐1‐[4‐(tributylstannyl)phenyl]‐2‐phenyl‐1‐butene have been synthesised as precursors to radiolabelled idoxifene, an important new drug for the treatment of breast cancer, and to aziridinyl 4‐iodotamoxifen, a potentially useful biological research tool for studying the action of tamoxifen, respectively.
Metallation/reduction as a new approach to tritium labeling. The synthesis of [3H]ibogaine
Authors: Seltzman Herbert H. , Odear Denise F. , Laudeman Christopher P. , Carroll F. Ivy , Wyrick Christopher D. 
Published: October 2006

AbstractA new method is presented for the tritiation of aryl compounds with tritium gas which is conducted on the underivatized substrate. Combined directed ortho metallation and facile reduction of the carbonpotassium bond affords incorporation of tritium at high specific activity under mild conditions. The metallation/reduction method is demonstrated for the preparation of [3H]ibogaine.
Difunctional two‐carbon molecules derived from [11C]cyanide
Authors: Thorell Jan‐Olov , Stone‐Elander Sharon , Elander Nils 
Published: October 2006

AbstractA synthetic strategy for producing new difunctional molecules for potential use as radiolabelling precursors derived from [11C]cyanide is presented. No‐carrier‐added [11C]CN− was reacted with chloromethyl pivalate to generate the nitrile [11C]cyanomethyl pivalate, which was subsequently converted to ethyl 1 [1‐11C]glycolate, 2, with acid and alcohol, or to [1‐11C]glycolic acid, 4, using aqueous acid. [1‐11C]Ethylene glycol, 3, and [2‐11C]2‐aminoethanol 5, were obtained by reduction of2 and 1, respectively, with lithium aluminum hydride. Conditions for obtaining conversions ca. 90% are described. By using a microwave wave‐guide cavity to speed up transformations requiring elevated temperatures, all five carbon‐11 labelled compounds were synthesized in less than a total of 3 min.
Radiosynthesis of (±)‐1‐(2‐bromo‐4,5‐dimethoxybenzyl)‐7‐hydroxy‐6‐methoxy‐2‐[11C]‐methyI‐l,2,3,4‐tetrahydro‐isoquinoline, [11C]A‐69024: A non‐benzazepine antagonist for studying dopamine D1 receptors In vivo using PET
Authors: Kassiou Michael , Mathews William B. , Musachio John L. , Ravert Hayden T. , Lambrecht Richard M. , Dannals Robert F. 
Published: October 2006

Abstract(±)‐1‐(2‐bromo‐4,5‐dimethoxybenzyl)‐7‐hydroxy‐6‐methoxy‐2‐[11C]‐methyl‐1,2,3,4‐tetrahydroisoquinoline, (HCJA‐69024, a selective ligand for the D1 receptor was prepared by N‐alkylation of (±)N‐desmethyl A‐69024 with [11C]methyl iodide in DMF. The radiotracer was purified by semi‐preparative reverse‐phase HPLC. The average specific activity was 1950 mCi/μmol calculated at end‐of‐synthesis (EOS). The average time of synthesis including formulation was 20 minutes.
Radiolabeling kit/generator for 5‐radiohalogenated uridines
Authors: Baranowska‐Kortylewicz Janina , Helseth Lynn D. , Lai Jing , Schneiderman Martin H. , Schneiderman G. Sue , Dalrymple Glenn V. 
Published: October 2006

AbstractA rapid, simple and inexpensive synthesis of 5‐radiohalogenated‐2′‐deoxyuridine from 5‐trimethylstannyl‐2′‐deoxyuridine is described. The total reaction and purification time including thin layer chromatography (tlc) for quality control is less than 30 min. This method produces excellent yields (>95%) of 123I‐, 125I‐, 131I‐UdR. The radiochemical purity of all tested preparations (>20) was determined to be greater than 99%. This new method is the basis of a radiolabeling kit/generator for preparation of radiohalogenated nucleosides. 2′‐Deoxyuridine (UdR) halogenated with a stable isotope of bromine was also synthesized indicating that the method can be applied to the preparation of 5‐radiobromo‐2′‐deoxyuridine (BUdR).
[11C]cyanogen bromide in the synthesis of 1,3‐di(2‐tolyl)‐[11C]guanidine
Authors: Westerberg Göran , Kärger Wiebke , Onoe Hirotaka , Långström Bengt 
Published: October 2006

AbstractThe title compound was 11C‐labelled in a one‐pot procedure using [11C]cyanogen bromide as the key intermediate. Synthesis time was 31–33 min counted from the end of bombardment, affording 1,3‐di(2‐tolyl)‐[11C]guanidine (6) in 87 % decay‐corrected radiochemical yield counted from [11C]cyanogen bromide. The specific radioactivity of the product at the end of synthesis was 118 GBq μmol−1 (3.2 Ci μmol−1). Autoradiographic studies on slide‐mounted rat brain sections showed specific binding of guanidine (6), but when injected intravenously into Rhesus monkey, brain uptake was very low, indicating that the 1,3‐di(2‐tolyl)‐[11C]guanidine did not cross the blood‐brain barrier.
Synthesis of (1, 2‐13C2) 2‐phosphoglycolic acid
Authors: O'Connor Edward J. , Tomita York , McDermott Ann E. 
Published: October 2006

AbstractThe synthesis of (1,2‐ 13C2) 2‐phosphoglycelic acid, 5, from commercially‐available (1,2‐ 13C2) bromoacetic acid is described along with some of its solution NMR characteristics.
Efficient routes to isotopically labelled epichlorohydrins ((chloromethyl) oxiranes)
Authors: O'Hagan David , White Jeffrey , Jones David A. 
Published: October 2006

AbstractEfficient routes are developed for the synthesis of variously labelled 2H‐ and 13C‐ labelled epichlorohydrins prepared from appropriately labelled acetic acids and sodium borodeuteride. The route is versatile and can be used for strategic location of isotopes at C‐1, C‐2 and C‐3 of epichlorohydrin. By way of demonstration [2‐13C]‐, [2‐2H]‐, [3‐2H2] and [2‐2H, 3‐2H2]‐ epichlorohydrins have been prepared. In addition the syntheses can be adapted for the preparation of enantiomerically pure and isotopically labelled epichlorohydrins.
Synthesis of 123I‐and labelled 5‐iodo‐6‐nitroquipazine
Authors: Mathis Chester A. , Enas Joel D. , Hanrahan Stephen M. , Akgün Eyup 
Published: October 2006

AbstractThe syntheses of the potent and selective serotonin reuptake complex radioligands [123I]‐ and [125I]5‐iodo‐6‐nitroquipazine (5‐iodo‐6‐nitro‐2‐piperazinylquinoline) are reported. A seven step synthetic sequence provided the BOC‐protected 5‐tributyltin‐6‐nitroquipazine precursor for radioiodination. End of synthesis radioiodination yields of ∼40% for 123I and ∼60% for 125I were achieved resulting in labelled products with high specific activities (>4000 and >2000 Ci/mmol, respectively) and radiochemical purities (>98%).
Synthesis of [2‐14C] fantofarone or 1‐[4‐[3‐N‐methyl N‐[3,4‐dimethyl β‐phenethyl] amino propyloxy] benzene sulfonyl]‐2‐isopropyl [2‐14C] indolizine
Authors: Pointeau P. , Berger Y. 
Published: October 2006

AbstractSodium [1‐14C] isobutyrate: 1 was obtained by carbonation of isopropyl magnesium bromide with 14CO2. From: 1 [1‐14C] isobutyryl chloride: 3 was prepared, which through the successive actions of diazomethane and hydrogen bromide gave rise to 1‐bromo 3 methyl [2‐14C] 2‐butanone: 5.The latter lead to the indolizine: 6 which by a route patterned after that used to make unlabelled Fantofarone gave the [2‐14C‐indolizyl] Fantofarone: 8 (specific radioactivity: 58.2 mCi/mMole) overall yield 9.9% based on [14C] BaCO3.
One‐step preparation of [2,3‐3H]1‐aminocyclopropanecarboxylic acid: A useful ligand for strychnine‐insensitive glycine receptors
Authors: Lewin A. H. , Lamb P. B. , Popik P. , Skolnick P. 
Published: October 2006

AbstractCatalytic hydrogenation of 1‐aminocyclopropenecarboxylic acid under tritium gas afforded [2,3‐3H]1‐aminocyclopropanecarboxylic acid with specific activity 26 Ci/mmol, determined by a combination of 1H and 3H NMR. Pilot radioligand binding assays indicate this compound will be a useful probe for the NMDA receptor‐associated strychnine‐insensitive glycine receptor.
Synthesis of [14C]E1077, a novel parenteral cephalosporin antibiotic
Authors: Kai Yasunobu , Chiku Shigeru 
Published: October 2006

Abstract(−)‐(RS)‐(E)‐3‐[(6R,7R)‐7‐((Z)‐2‐(5‐amino‐1,2,4‐thiadiazol‐3‐yl)‐2‐fluoromethoxyiminoacetamide]‐2‐carboxy‐8‐oxo‐5‐thia‐1‐azabicyclo[4.2.0]oct‐2‐ene‐3‐yl[‐2‐propenyl](carbamoylmethyl) ethylmethylammonium hydroxide inner salt (E1077), a new parenteral cephalosporin with well‐balanced antibacterial spectrum and potent antibacterial activity, was labelled with carbon‐14, starting from potassium [14C]thiocyanate which on reaction with (Z)‐2‐(N‐chloroamidino)‐2‐fluoromethoxyiminoacetic acid (I) gave(Z)‐2‐(5‐amino‐1,2,4‐[5‐14C]thiadiazol‐3‐yl)‐2‐fluoromethoxyiminoacetic acid (II).(RS)‐[(E)‐3‐](6R,7R)‐7‐Amino‐2‐carboxy‐8‐oxo‐5‐thia‐1‐azabicyclo[4.2.0]oct‐2‐ene‐3‐yl[‐2‐propenyl](carbamoylmethyl) ethylmethylammonium hydroxide inner salt (III) was acylated with the above acid using the POCl3‐DMF method, to afford the title compound (IV); [14C]E1077, having a specific activity of 3.36 MBq/mg, was obtained in 50.3% overall radiochemical yield, with a radiochemical purity of more than 97.1%.
Synthesis of (R)‐(+)‐1,2,3,6‐tetrahydro‐4‐[U‐14C]phenyl‐1‐ [(3‐phenyl‐3‐cyclohexenyl‐1‐yl)methyl]pyridine, a potential antipsychotic agent
Authors: Ekhato I. Victor , Huang Che C. 
Published: October 2006

Abstract1,2,3,6‐Tetrahydro‐4‐[U‐14C]phenylpyridine (12) was synthesized and coupled to (R)‐3‐phenyl‐3‐cyclohexene‐1‐carboxylic acid to make the titled compound 7 in 21% overall yield. Purification considerations were an important factor in the choice of a reaction sequence to 7, and successful synthesis was facilitated by the superiority of BF3.OEt2 as dehydrating reagent in this system. This otherwise problematic sequence offers an efficient and simple route to compound 7 (PD 143188).