bluuebunny/crossref_metadata_2025_split huggingface dataset:
A potentially general synthesis of high specific activity specifically labelled tritiated peptides: Synthesis of [D‐3‐(2‐naphthyl)‐[2,3‐3H]alanine6]LHRH
Authors: Parnes Howard , Shelton Emma J. 
Published: October 2006

AbstractHigh specific activity (43.7 Ci/mmol) D‐3‐(2‐naphthyl)‐[2,3,‐3H] alanine (7) was obtained by reduction of methyl 2‐N‐acetylamino‐3‐(2‐naphthyl) acrylate (5) with carrier free tritium in the presence of (Ph3P)3RhCl followed by enzymatic resolution and hydrolysis. Reductions of 5 and other substrates catalyzed by Pd/C afforded products of low to medium specific activity (0.1–17 Ci/mmol).A synthetic approach which maximizes the specific activity, guarantees specificity of label, and may be applied toward the preparation of any tritiated (or 14C) peptide is suggested.The synthesis of the decapeptide [D‐3‐(2‐naphthyl)‐[2,3‐3H]alanine6]LHRH (12) at 45.7 Ci/mmol, using this methodology, is described.
The synthesis of C‐13 labeled vitamin E, [12′‐13C] all‐rac‐α‐tocopherol
Authors: Urano Shiro , Nakano Shun‐Ichiro , Matsuo Mitsuyoshi 
Published: October 2006

Abstract[12′‐13C]all‐rac‐α‐Tocopherol (1) was synthesized from [2‐13C]acetone. The condensation of 6‐methoxymethoxy‐2,5,7,8‐tetramethyl‐2‐(5‐mercaptothiazolinyl‐4‐methyl‐3‐penten‐1‐yl)chroman (8) with [7‐13C]geranyl bromide (7), which was prepared by the coupling of (6‐benzoyloxy‐4‐methyl‐4‐hexenyl)triphenylphosphonium bromide (5) with [2‐13C]acetone following bromination, afforded [12′‐13C]6‐methoxymethoxy‐2,5,7,8‐tetramethyl‐2‐(3E,7E,9E)‐5‐mercaptothiazolinyl‐(4,8,12‐trimethyl‐3,7,9‐tridecatrien‐1‐yl) chroman (9). After desulfurization and reduction of 9, the reaction product obtained was converted into [12′‐13C]all‐rac‐α‐tocopherol (1) by hydrolysis. The total yield of 1 was 33.7% on the basis of [2‐13C]acetone.
The synthesis of oxygen‐18 enriched phenol and naphthol from 18O2
Authors: Walker T. E. , Goldblatt M. 
Published: October 2006

AbstractPhenols enriched with oxygen‐18 can be synthesized using an acid exchange reaction in H218O at elevated temperature, however, to obtain highly enriched products very large quantities of water must be used and recycled. Grignard reagents will react readily with oxygen gas with almost no isotopic dilution to produce the 18O enriched alcohol or phenol. Aromatic Grignards do not produce as high a yield as the aliphatic Grignards, however, both provide convenient routes to labeled products. The yield of naphthol from an aryl halide can be improved by the addition of an aliphatic halide (which produces the alcohol as a by product), however, the yield of naphthol from 18O2 gas is not improved by this approach. Either 1‐bromo‐naphthalene or bromobenzene was converted into the Grignard reagent and reacted with oxygen‐18 enriched gas at 0° in a sealed reaction system. The reaction was worked up in the conventional manner and the yields from 18O2 were 34% for [18O] phenol and 23% for 1‐[18O]naphthol.
Preparation of sodium cromoglycate (intalR) labelled with isotopic hydrogen
Authors: Lockley W J S , Wilkinson D J 
Published: October 2006

AbstractProcedures for the labelling of the anti‐allergic drug, sodium cromoglycate, with both tritium and deuterium are described. Sodium [6,6′,8,8′‐2H] cromoglycate was prepared by acid catalysed exchange with deuterosulphuric acid. The 2‐2H and 2‐3H isotopomers were prepared via borodeuteride and borotritide reductions of an oxo‐precursor. Sodium [3,3′‐3H] cromoglycate was prepared at high specific radioactivity by rhodium(III) chloride catalysed exchange with high atom % abundance tritiated water.
Specific radioactivity determinations of ionic organic compounds of high specific activity by fast atom bombardment and field desorption mass spectrometry
Authors: Lehmann W. D. , Kaspersen F. M. 
Published: October 2006

AbstractCarbon‐14 and tritium labelled ionic organic compounds such as quaternary ammonium salts, steroid sulphates, bile acid conjugates, and oligopeptides have been analyzed for their label distribution and for their specific radioactivity by fast atom bombardment and field desorption mass spectrometry. No significant differences between the quantitative results with both techniques are found. The minimal specific radioactivities detectable by this approach are about 20 MBq mmol−1 or 10 GBq mmol−1 for compounds labelled with one atom of carbon‐14 or one atom of tritium per molecule, respectively. Specific radioactivity determinations of highly labelled biochemicals are characterized by a precision and an accuracy in the region between 1% and 5%.
Preparation of high purity carbonyl[35S]sulphide
Authors: Kluczewski S. M. , Brown K. A. , Bell J. N. B. , Sandalls F. J. , Jones B. M. R. , Minski M. J. 
Published: October 2006

AbstractThe title compound was synthesised by the reaction between elementary[35s]sulphur and carbon monoxide at 300°C, and purified by passage over Porapak QS. The only detectable S‐impurity in the purified product was CS2 at <0.05% (v/v) of the COS concentration.
Application of the nucleophilic substitution reaction to the synthesis of No‐carrier‐added [18F]fluorobenzene and other 18F‐labeled aryl fluorides
Authors: Shiue C.‐Y. , Watanabe M. , Wolf A. P. , Fowler J. S. , Salvadori P. 
Published: October 2006

AbstractNo‐carrier‐added (NCA) [18F]fluorobenzene was prepared in a multistep synthesis with a radiochemical yield of 20‐30%.A series of NCA and CA 18F‐labeled aryl fluorides which are important precursors of 18F‐labeled butyrophenone neuroleptics have also been synthesized in radiochemical yields of 30–50%. The direct synthesis of [18F]spiroperidol and [18F]benperidol from the parent compounds and/or nitro and/or chloro compound using the nucleophilic substitution reactions were also investigated.
The preparation of [15N,15N′]‐ and [4,4′‐13C2]‐4,4′‐dichloroazobenzene and [15N, 15N′]‐4‐chloroazobenzene
Authors: Shine Henry J. , Rhee Eun Sook 
Published: October 2006

AbstractSyntheses of specifically labelled [15N,15N′]‐ and [4,4′‐13C2]‐4,4′‐dichloroazobenzene and [15N, 15N′]‐4‐chloroazobenzene have been accomplished.
Deuterium, tritium, and carbon‐14 labeling of 9‐[ [2‐methoxy‐4‐[ (methylsulfonyl)amino]phenyl] amino]‐N, 5‐dimethyl‐acridinecarboxamide (CI‐921), a new antitumor agent
Authors: Hays Sheryl J. , Huang C. C. 
Published: October 2006

AbstractCI‐921 2, a potent antitumor agent has been labeled with deuterium and tritium by an exchange reaction employing platinum black as a catalyst. The title compound was carbon‐14 labeled from 2‐chloro‐benzoic‐carboxy‐14C acid to produce the isethionic salt 2d with a specific activity of 26.9 mCi/mmol. The overall radiochemical yield for the carbon‐14 sequence was 22%.
Synthesis of a highly tritiated photoaffinity labelled pheromone analog for the moth antheraea polyphemus
Authors: Prestwich Glenn D. , Golec Frederick A. , Andersen Niels H. 
Published: October 2006

AbstractThe synthesis of the tritiated sex pheromone of the saturniid moth Antheraea polyphemus was accomplished by stereospecific T2 reduction of (E)‐hexadec‐6‐en‐11‐yn‐1‐yl acetate. The [11, 12‐3H2]‐(E, Z)‐6, 11‐hexadecadieny 1 acetate was then converted to the corresponding diazoacetate, a behaviorally active photoaffinity label for the A. polyphemus pheromone binding and receptor proteins. Synthesis of the enyne precursors is also described.
Synthesis, characterization, and in vivo disposition of iodinatable polyethylene glycol derivatives: Differences in vivo as a function of chain length
Authors: Larwood David J. , Szoka Francis C. 
Published: October 2006

AbstractA series of iodinatable water soluble polyethylene glycol (PEG) derivatives were prepared for use as model hydrophilic drugs. Polyethylene glycol diamine 6000 was coupled to methyl p‐hydroxybenzimidate, and PEG 1900‐ and PEG 5000‐monomethyl ethers were coupled to tyramine and histamine. The derivatives underwent facile iodination with the chloramine‐T reaction and were stable under a wide range of conditions. The larger derivatives showed rapid renal clearance, but the 1900 MW compounds underwent significant clearance via the bile.
The synthesis of deuterium labelled mono‐hydroxy metabolites of phenytoin
Authors: Hoskins John A 
Published: October 2006

AbstractThe synthesis of the 3‐hydroxyphenyl and 4‐hydroxyphenyl metabolites of 5,5‐diphenylhydantoin (Phenytoin) labelled with deuterium in either of the two phenyl rings and 5(4‐hydroxy‐[2H4]phenyl)‐5‐[2H5] phenylhydantion is described.
Probes for narcotic receptor mediated phenomena 8. Tritiation of irreversible mu or delta specific opioid receptor affinity ligands to high specific activity
Authors: Burke Terrence R. , Rice Kenner C. , Jacobson Arthur E. , Simonds William F. , Klee Werner A. 
Published: October 2006

AbstractTritiation of the delta‐specific opioid alkylating ligand FIT, 3 and the mu‐specific opioid alkylating ligand BIT, 9 to high specific activity is described. Both compounds were derived from dibrominated amino intermediates (4 and 10, respectively) which were tritiated with tritium gas over Pd/C before conversion of the amine functions to isothiocyanates.
Synthesis of [2‐d]estradiol, [4‐d]estradiol, [2‐t]estradiol and [4‐t]estradiol with high specificity
Authors: Porubek David J. , Namkung Moses J. , Juchau Mont R. , Nelson Sidney D. 
Published: October 2006

Abstract17‐β‐Estradiol has been labeled in the 2 or 4 position with tritium or deuterium. Both 2‐ and 4‐iodoestradiol were prepared by treatment of estradiol with N‐iodosuccinimide in ethanol followed by chromatographic separation. Reductive dehalogenation of 2‐ and 4‐iodoestradiol with tritium gas gave [2‐t] estradiol and [4‐t] estradiol, respectively, with specific activities of approximately 2 Ci/mmole. Greater than 99% of the radiolabel was incorporated into the target positions as determined by rehalogenation of the radiolabeled compounds. Analysis of the deuterium labeled compounds, [2‐d] estradiol and [4‐d] estradiol, similarly prepared by reduction with deuterium gas, revealed that isotope incorporation was high and specific.
Syntheses of 2‐([14C]methyl)furan and 4‐oxo[5‐14C]‐2‐pentenal
Authors: Ravindranath Vijayalakshmi , Burka Leo T. , Boyd Michael R. 
Published: October 2006

AbstractA simple one‐step syntheses of 2‐([14C]‐methyl) furan and 4‐oxo‐[5‐14C]‐2‐pentenal have been described. Carbon‐14 labeled 2‐methylfuran was synthesized by treatment of 2‐furyl lithium with 14C‐methyl iodide, and 14C‐acetylacrolein was obtained by peracid oxidation of labeled 2‐methylfuran.
A facile microsynthesis of 14C‐labelled picene
Authors: Beermann Dieter , Petrovic Peter , Seidel Albrecht , Oesch Franz 
Published: October 2006

AbstractMicroscale Wittig olefination of commercially available [7‐14C]‐benzal dehyde of high specific radioactivity with aryl bromomethyl phosphonium salt and subsequent oxidative photocyclisation affords pure 14C‐labelled picene in efficient yield.
Synthesis of 11C‐labelled choline
Authors: Diksic Mirko , Yamamoto Y. Lucas , Feindel William 
Published: October 2006

AbstractWe report the synthesis of 11C‐labelled choline using the reaction of “nocarrier‐added” 11C‐labelled methyliodide and 2‐amino‐(N,N‐dimethyl)‐ethanol. After determining the optimum temperature and duration for the reaction, we achieved a radiochemical yield of about 30% and the radioactivity levels needed for PET studies in humans.
Radiosynthesis of no‐carrier‐added 75,77Br‐brombenperidol
Authors: Moerlein S. M. , Stöcklin G. 
Published: October 2006

AbstractA three‐step synthesis of the neuroleptic benperidol is presented, and the rapid no‐carrier‐added (n.c.a.) radiobromination of this compound to form brombenperidol (BBP), a radiolabelled dopaminergic receptor‐binding ligand, is described. N.c.a. radiobromination of benperidol using dichloramine‐T in trifluoroacetic acid at elevated temperatures results in bromination totally at the benzimidazolinyl ring of the neuroleptic, leaving the molecular characteristics necessary for receptor binding unaltered. Radiopharmaceutical production results in n.c.a. 75,77Br‐brombenperidol with a corrected radiochemical yield of 30% and a specific activity exceeding 8,000 Ci/mmol.
Synthesis of N‐hydroxymethylpentamethylmelamine (ring 14C), a cytotoxic‐alkylating metabolite of hexamethylmelamine
Authors: Sanders Mark E. , Ames Matthew M. 
Published: October 2006

AbstractThe 14C‐ring labeled carbinolamine N‐hydroxymethylpentamethyl‐melamine, a metabolite of the clinically useful anticancer agent hexamethylmelamine, was prepared in good yield from cyanuric chloride (ring, 2,4,6,‐14C). Amination of cyanuric chloride with dimethylamine gave 2‐chloro‐4,6‐bis(dimethylamino)‐1,3,5‐triazine‐2,4,6‐14C. Further amination with anhydrous methylamine gave pentamethylmelamine‐2,4,6‐14C. Condensation of pentamethylmethyl‐melamine with excess aqueous formaldehyde gave N‐hydroxymethylpentamethylmelamine in 54% overall yield.
Synthesis of N‐[35S]‐sulpho‐2‐amino tricarballylate
Authors: Brown Malcolm R. , Shankar Ravi , Sallis John D. 
Published: October 2006

AbstractThe synthesis of [35S]‐labelled N‐sulpho‐2‐amino tricarballylate (SAT) and methods for its purification and analysis are described. In the first stage of the two‐step synthesis, chloro‐[35S]‐sulphonic acid is reacted with pyridine to yield pyridine‐[35S]‐sulphur trioxide. This agent is then utilized to sulphonate 2‐amino tricarballylic acid yielding the ultimate product [35S]‐SAT, which was required for pharmacokinetic studies.
Two syntheses of 7,8‐dichloro‐1,2,3,4‐tetrahydroisoquinoline‐1‐14C
Authors: Mendelson Wilford L. , Villani Anthony J. , Petka Louis A. , Spainhour Charles B. 
Published: October 2006

AbstractTwo complementary radiosynthetic routes to the potent PNMT inhibitor 7,8‐dichloro‐1,2,3,4‐tetrahydroisoquinoline‐1‐14C(1) from 2,3‐dichlorobenzaldehyde‐formyl‐14C(4) are described. In the Pomeranz‐Fritsch sequence isoquinoline 6 was prepared from Schiff's base 5. Catalytic hydrogenation of 6 (H2/PtO2) furnished 1 in 28% radiochemical yield from 4. In the aluminum chloride fusion sequence, 4 was converted via amino alcohol 7 to chloro amine 8. Treatment of the latter with aluminum chloride/ammonium chloride (fusion, 190°C) yielded labeled 1 in 31% radiochemical yield from 4.
1,3,5‐Trinitroso‐ and 1,3,5‐trinitrohexahydro‐1,3,5‐triazine‐2H6
Authors: Boyer Joseph H. , Kumar G. 
Published: October 2006

AbstractPerdeuteration of 1,3,5‐trinitrosohexahydro‐1,3,5‐triazine was brought about by treatment with potassium alkoxide in CH3O2H(99.5%). The important high energy compound, 1,3,5‐trinitrohexahydro‐1,3,5‐ triazine (RDX), was obtained in its perdeuterated modification (>99% 2H) by oxidation of the perdeuterated trinitrosamine with a mixture of nitric acid (100%) and hydrogen peroxide (30%).
Synthesis and physico‐chemical properties of (R, S)‐6‐ditrideuteriomethylamino‐4,4‐diphenylheptan‐3‐one hydrochloride (methadone‐d6)
Authors: Gérardy Bruno M. , Poupaert Jacques H. , Vandervorst Daniel , Dumont Pierre , Declerq Jean‐Pierre , Van Meerssche Maurice , Portoghese Philip S. 
Published: October 2006

AbstractA reaction sequence is described to synthesize (R, S)‐6‐ditrideuteriomethylamino‐4,4‐diphenylheptan‐3‐one hydrochloride ( methadone‐d6.HCl ) in 10.5% overall yield starting from dimethylamine‐d6 hydrochloride. While methadone‐d6.HCl had rather similar physicochemical properties compared to methadone.HCl in the solid phase, a divergent behaviour was observed in solution ( pKa, chromatographic and 13C‐NMR data ). A higher basicity along with a more important hydrophilicity were observed for the d6‐derivative. A 13C‐NMR study showed significant differences in the 13C chemical shifts, which were attributed in part to the intrinsic nature of D itself and in part to a conformational perturbation. The longer duration of antinociceptive action, along with higher t1/2 and clearance, and the depression of the metabolic N‐demethylation process were the only biological properties modified by the deuteration.
synthesis of 10‐[3H]‐5H‐dibenz[b, f] azepine‐5‐carboxamide ([3H]‐carbamazepine)
Authors: Brundish D. E. 
Published: October 2006

AbstractThe title compound has been prepared from a bromo derivative at a specific activity of 27 Ci mmol−1 with radiochemical purity of 98.4% by a selective catalytic reduction with tritium gas. Bromine was replaced without reduction of the stilbene double bond using a poisoned, deactivated catalyst.
Synthesis of 3′‐CTNU radiolabelled with 14C in the alkylating moiety and 3H in the carbamoylating moiety
Authors: Brubaker William F. , Prusoff William H. 
Published: October 2006

Abstract[6‐3H]3′‐[3‐(2‐Chloroethyl)‐3‐nitrosoureido]‐3′‐deoxythymidine ([3H]3′‐CTNU) radiolabelled with 3H in the carbamoylating moiety has been synthesized in high yield by conversion of tritiated 3′‐amino‐3′‐deoxythymidine([3H]3′‐ATdR) to [6‐3H]3′‐[3‐(2‐chloroethylureido)]‐3′‐deoxythymidine ([3H]3′‐UTdR), followed by nitrosation with N2O3 gas. The title compound radiolabelled with 14C in the alkylating moiety was prepared by conversion of [2‐14C]ethanolamine hydrochloride to [1‐14C]chloroethylamine hydrochloride, followed by reaction with phosgene to yield [1‐14C] chloroethyl isocyanate. This was converted to 3′‐3‐([1‐14C] 2‐chloroethylureido)‐3′‐deoxythymidine([14C]3′‐UTdR), and nitrosated to afford 3′‐[3‐([1‐14C] 2‐chloroethyl) ‐3‐nitrosoureido]‐3′‐deoxythymidine ([14C]3′‐CTNU). HPLC methodology was developed for the purification of intermediate and final products.
Synthesis of 14C‐labeled and 2H‐labeled dibucaine
Authors: Chaudhuri Naba K. 
Published: October 2006

AbstractA synthesis of dibucaine labeled with 14C in the heterocyclic ring is described. The synthesis was accomplished in five steps starting with isatin and acetic anhydride‐2‐14C as shown in Scheme I. Two deutero analogs, dibucaine‐d2 and dibucaine‐d9, were also synthesized by the reactions shown in Scheme II. Dibucaine‐d9, was synthesized by condensation of 2‐chloro‐N‐[2‐(diethylamino)ethyl]‐4‐quinoline carboxamide with sodium salt of n‐butyl‐d9 alcohol. Dibucaine‐d2 was synthesized by condensation of 2‐chloroquinoline carboxylic acid chloride with N,N‐diethyl dideutero‐ethylenediamine (prepared from chloroacetyl chloride) followed by reaction with sodium n‐butoxide. 14C‐labeled dibucaine was found to undergo considerable radiolysis on storage to give 2‐butoxy‐quinoline‐4‐carboxamide as a major decomposition product.
Synthesis of deuterium‐labeled imipramine using acid‐catalyzed exchange reaction
Authors: Baba S. , Furuta T. , Sasaki Y. , Kasuya Y. 
Published: October 2006

AbstractSynthesis of three forms of selectively deuterated imipramine with high isotopic purity using acid catalyzed hydrogen‐deuterium exchange reaction is described. Deuterated imipramine labeled at the positions of 2,4,6 and 8 [IP‐d4(I)] was prepared directly by heating imipramine in 10% DCl‐D2O at 80° for 8hr. Imipramine labeled at all of the eight aromatic positions (IP‐d8) was synthesized from iminodibenzyl‐1,2,3,4,6,7,8,9‐d8 which was prepared by treating iminodibenzyl (IDB) in 37% DCl‐D2O at 160° for 24hr. And imipramine labeled at the positions of 1,3,7 and 9 [IP‐d4(II)] was obtained by “back‐exchange” of IP‐d8 under the protio condition according to the exchange procedure of IP‐d4(I).
The syntheses of 1‐[11C]‐D‐glucose and related compounds for the measurement of brain glucose metabolism
Authors: Shiue Chyng‐Yann , Wolf Alfred P. 
Published: October 2006

AbstractA new synthesis of 1‐[11C]‐D‐glucose (3) and related compounds from H11CN is described. Reaction of D‐arabinose (1) with Na11CN at pH 8 gives 1‐[11C]‐aldononitriles (2). Reduction of 2 with Raney alloy in 30% formic acid gives 1‐[11C]‐D‐glucose (3) and 1‐[11C]‐D‐mannose (4) in radiochemical yields of ∼ 40–50% (EOB) in a synthesis time of 50 min from EOB. The yield and ratio of 3 and 4 is pH dependent. Compounds 3 and 4 are separated by HPLC. The radiochemical yield of 3 is ∼ 15% (EOB) and the total synthesis time (including HPLC purification) is 70 min from EOB. The same method has also been applied to synthesize 1‐[11C]‐D‐galactose (6) with radiochemical yields of ∼ 30% (EOB) in a synthesis time of 70 min from EOB. The advantages and disadvantages of this synthetic method are discussed.
Synthesis of 14C‐labelled 1‐(3,5‐bis‐trifluoromethyl)‐phenyl‐4‐methyl thiosemicarbazide, C 2696‐GO
Authors: Maller R. K. , Nagarajan K. , Zoebeli H. 
Published: October 2006

AbstractFor pharmacokinetic and metabolism studies in experimental animals C 2696‐Go was labelled initially with 14C on the thiocarbonyl carbon of the thiosemicarbazide moiety of the molecule, having a specific activity of 3.14 μCi/mg, in a radiochemical yield of 43%, based on the starting potassium [14C]thiocyanate.C 2696‐Go alternatively labelled with 14C on one of the trifluoromethyl groups, having a specific activity of 3.6 μCi/mg was also synthesized in an overall radiochemical yield of 5.1%, starting from Ba[14C]O3.
Synthesis of [5,6‐13C2, 1‐14C]olivetolic acid, methyl [1′‐13C]olivetolate and [5,6‐13C2, 1‐14C]cannabigerolic acid
Authors: Porwoll Joseph P. , Leete Edward 
Published: October 2006

AbstractPotential advanced intermediates in the biosynthesis of Δ9‐tetrahydrocannabinol have been synthesized labeled with two contiguous 13C atoms and 14C. Methyl [5,6‐13C2, 1‐14C]olivetolate was prepared from lithium [13C2]acetylide and dimethyl [2‐14C]malonate. Reaction with geranyl bromide afforded methyl [5,6‐13C2, 1‐14C]cannabigerolate, and hydrolysis of these methyl esters with lithium propyl mercaptide yielded the corresponding labeled acids. The 13C‐13C couplings observable in the 13C NMR spectra of these 13C‐enriched compounds and their synthetic precursors are recorded. Methyl [1′‐14C]olivetolate was prepared from 13CO2 to confirm assignments of the 13C chemical shifts in the pentyl side chain of these compounds.
Microscale synthesis of volatile, 14C‐labelled acid chlorides
Authors: Parnes Howard , De Keczer Steve 
Published: October 2006

AbstractA method for the microscale (one mmole) synthesis of volatile, 14C‐labelled acid chlorides from Ba14CO3 using vacuum line techniques is described. By a judicious choice of reagents, desired intermediates and products may be isolated in high yield by simple vacuum transfer techniques without fractionation.
Synthesis of [4‐3H]‐2‐pyrrolidinone, [4‐3H]‐N‐methyl‐2‐pyrrolidinone and N‐[14C‐methyl]‐2‐pyrrolidinone
Authors: Wells David A. , Chaney James E. , Digenis George A. 
Published: October 2006

AbstractAn efficient synthesis of 2‐pyrrolidinone and N‐methyl‐2‐pyrrolidinone was developed in which the compounds can be labeled with tritium at either the 3‐ and 4‐positions or the 4‐position of the lactam ring. Cyclization of [2,3‐3H]‐γ‐aminobutyric acid (GABA) yielded [3,4‐3H]‐2‐pyrrolidinone and cyclization of [3‐3H]‐GABA, prepared by acid‐catalyzed exchange of tritium from [2,3‐3H]‐GABA, yielded [4‐3H]‐2‐pyrrolidinone was synthesized by methylation of [3,4‐3H]‐2‐pyrrolidinone using phase transfer catalysis, followed by basecatalyzed tritium exchange. N‐[14C‐Methyl]‐2‐pyrrolidinone was prepared from [14C] methyl iodide and 2‐pyrrolidinone, also using phase transfer catalysis.
Synthesis and 3H NMR of 3H‐alaproclate of high specific activity
Authors: Bengtsson Stefan , Gawell Lars , Högberg Thomas , Sahlberg Christer 
Published: October 2006

AbstractThe antidepressant alaproclate (1) is a selective inhibitor of neuronal serotonin reuptake with low affinity for other receptor sites. 3H‐Alaproclate (3, 2‐([2,5‐3H2]‐4‐chlorophenyl)‐2‐methyl‐2‐propyl 2‐aminopropanoate) with high specific activity (38 Ci/mmol) was prepared by hydrogenolysis of its 2,5‐dibromo analogue 2 with tritium gas. The compound 2 was prepared in a seven step synthesis from 4‐chlorotoluene. The position of the tritium incorporation was verified by 3H NMR.