bluuebunny/crossref_metadata_2025_split huggingface dataset:
Specific 14c‐labeled surfactants. The addition of homogeneous polyoxyethylene glycols to 2,6,8‐trimethyl‐4‐nonanol
Authors: Tanaka F. S. , Wien R. G. , Stolzenberg G. E. 
Published: October 2006

AbstractTwo molecularly homogeneous nonionic detergents with specific‐14C labeling were prepared. Polyoxyethylene glycols of six and nine ethylene oxide units were coupled to 2,6,8‐trimethyl‐4‐nonanol (TMNOH). The radioactive label was in the first ethylene oxide unit attached to the alkyl moiety, TMNOCH2*CH2(OCH2 CH2)nOH. All react ions employed in this synthesis gave good to excellent results. Two routes were developed for the reduction of an alkoxyacetic acid intermediate to the corresponding alcohol, and both methods gave excellent yields. The overall yields for TMN(OCH2CH2)6OH and TMN(OCH2CH2)9OH were 4Z and 33 per cent, respectively.
Preparation of tritiated substituted estratrienes
Authors: Fraser A. D. , Clark S. J. , Wotiz H. H. 
Published: October 2006

Abstract2,4‐Dibromo‐1,3,5(10)‐estratriene‐3,6β,17β‐triol, 2,4‐dibromo‐1,3,5(10)‐estratriene‐3,7α,17β‐triol and 2,4‐dibromo‐1,3,5(10)‐estratriene‐3,16β,17β‐triol were prepared by bromination with N‐bromosuccinimide. 2,4‐Diiodo‐1,3,5(10)‐estratriene‐3,7α,17β‐triol, 2,4‐diiodo‐1,3,5 (10)‐estratriene‐3,11β,17β‐triol and 2,4‐diiodo‐1,3,5(10)‐estratriene‐3, 16α‐diol were formed by direct iodination with I2. Hydrogenolysis of the dihalo estrogen derivatives by tritium gas over 5% palladium/Al2O3 gave the 2,4‐tritiated parent compounds in good yield with high specific activity.
Preparation of 3H‐labeled ochratoxins
Authors: Chang Fred C. , Chu F. S. 
Published: October 2006

Abstract3H‐Ochratoxins A, B, and C were obtained by tritiation of the toxins with tritiated water in acetic acid and platinum at 80° C overnight. The toxins were purified by solvent partition and thin layer chromatography with the recovery yield being 80% and the specific activity being 2.6 – 3.0 Ci/mmol. Hydrolysis of 3H‐ochratoxin A with carboxypeptidase A revealed that 80.9% of the tritium in ochratoxin A molecule distributed on the phenylalanine residue with only 19.1% in ochratoxin a moiety.
The synthesis of 2‐chlorobiphenyl‐1′,2′,3′,4′,5′,6′‐14c6, [1]
Authors: Reichardt Paul B. , Schuttner Scott E. 
Published: October 2006

AbstractModification of the traditional. Gomberg reaction conditions provides a simple, economical. route to 2‐chlorobiphenyl‐1′,2′,3′,4′,5′,6′‐14C6 (I). The reaction of benzene‐U‐14C6 with an excess of the diasonium salt from 2‐chloroaniline produces 14C‐labelled I in 10% radiochemical. yield. This method should be applicable to the preparation of any chlorinated biphenyl having one unsubstituted ring.
Synthese d'une pyridazine d'interet therapeutique, marquee au carbone 14: Dichlorhydrate de morpholinoethylamino‐3 methyl‐4 phenyl‐6 pyridazine 14C‐6 (30,038 CB)
Authors: Pichat L. , Beaucourt J. P. , Krausz F. , Moulineau C. 
Published: October 2006

AbstractBenzoyl chloride‐714C is condensed with tris(trimethylsilyl) 1‐lithio‐1,1,2 propane tricarboxylate, which after hydrolysis gives rise to a 66% yield of 2‐methyl‐3‐(benzoyl‐7‐14C) propionic acid. After cyclisation with hydrazine, followed by treatment with bromine in acetic acid, 3‐hydroxy‐4‐methyl‐6‐phenyl pyndazine 6‐14C is secured in a 77% yield. This hydroxypyridazine treated with POCl3 gave a 90% yield of 90 % pure 4‐methyl‐6‐phenyl‐3‐chloropyndazine 6‐14C; The latter treated with 2‐morpholino‐1‐aminoethane in presence of sodium iodide has given 3‐morpholinoethylamino 4‐methyl 6‐phenylpyndazine 6‐14C. The overall yield based on barium carbonate 14C is 16.7 % (specific activity 18.5 mCi/mMole).
Labelling of an anti‐inflammatory agent with carbon‐14, synthesis of 5‐methoxy‐2‐methyl‐1‐(3,4‐methylenedioxybenzoyl) indole‐2‐14C‐3‐acetic acid
Authors: Nakatsuka Iwao , Hazue Masaaki , Makari Yoshiaki , Kawahara Kazuo , Endo Michio , Yoshitake Akira 
Published: October 2006

Abstract5‐Methoxy‐2‐methyl‐1‐(3,4‐methylenedioxybenzoyl)indole‐3‐acetic acid (ID‐955)(I), a new anti‐inflammatory agent, was labelled with carbon‐14 at C‐2 position of indole nucleus for the use of metabolic studies. The procedure used is shown in Fig. 1 and 2. Levulinic‐4‐14C acid was synthesized in 57% yield by condensation of ethyl acetoacetate‐3‐14C with ethyl bromoacetate and subsequent decarboxylation with hydrochloric acid. Reaction of III with N1‐(3,4‐methylenedioxybenzoyl)‐4‐methoxyphenylhydrazine (II) gave ID‐955‐2‐14C (I) in 58% yield. A total of 10.6 mCi of pure ID‐955‐2‐14c (I) was obtained, representing 25% radiochemical yield from sodium acetate‐1‐14C.
Synthesis of 2,4‐diamino‐6‐piperidinylpvrimidine‐3‐oxide‐3′,4′,;5′‐3h(n) tritiated minoxidil
Authors: Gilbertson Terry J. 
Published: October 2006

AbstractMinoxidil‐3′,4′,;5′‐3H(N), 25.6 Ci/mM. has been synthesized by the reaction of piperidine‐3,4,5‐3H(N) with 2,4‐diamino‐6‐chloro‐pyrimidine‐3‐oxide. Purification was by paper chromatography. Minoxidil prepared in this way was shown to be suitable for radioimmunoassay and was stable for six months stored in MeOH at 4° C.
The synthesis of 2,6‐dichlorobenzylidene aminoguanidine acetate [α‐14C]
Authors: Sisenwine Samuel F. , Tio Cesario O. , Ahern Jenny 
Published: October 2006

Abstract2,6‐Dichlorobenzylidene aminoguanidine acetate, a new antihypertensive agent, was labelled with 14C at the benzal position for metabolic studies. The key reaction involved the reduction of the sterically hindered 2,6‐dichlorobenzonitrile [cyano‐14C] with lithium aluminum hydride to 2,6‐dichlorobenzaldehyde [carbonyl‐14C]. The labelled nitrile was prepared by a Sandmeyer reaction employing 2,6‐dichloroaniline and K14CN. Further reaction of the labelled aldehyde with aminoguanidine bicarbonate produced the desired radioactive drug.
Preparation of nicotinic‐5‐2H acid from 5‐bromonicotinic acid
Authors: Clark Brian R. 
Published: October 2006

AbstractMethyl nicotinate‐5‐2H was prepared in dry tetrahydrofuran by palladium‐catalyzed deuterolysis of methyl 5‐bromonicotinate. Acid hydrolysis of the crude reaction mixture resulted in a 92% yield of deuterium‐labeled nicotinic acid of which 80 mole% was nicotinic‐5‐2H acid and 12 mole% was nicotinic‐5‐2H acid containing an additional deuterium atom elsewhere in the molecule. The structure assignment was based on the results of nuclear magnetic resonance spectroscopy, mass spectroscopy, ultraviolet spectroscopy, and elemental analysis.
The preparation of 14C‐labelled 6‐nbutyl‐2,8‐dicarboxy‐4,10‐dihydroxy‐1,7‐phenanthroline (ICI 74,917)
Authors: Bigg D. C. H. 
Published: October 2006

AbstractThe preparation of 6‐nbutyl‐2,8‐dicarboxy‐4,10‐dihydroxy(3,9‐14C)‐1,7‐phenanthroline (ICI 74,917) from ethyl acetate‐2‐14C is described. The overall radiochemical yield was 12%, at a specific activity of 29.7 μCi/mg.
A high yield synthesis of 13C‐ and 14C‐labeled diethyl carbonate
Authors: Porter William R. , Spitznagle Larry A. , Trager William F. 
Published: October 2006

AbstractLabeled silver carbonate was prepared from barium carbonate‐13C or ‐14C and aqueous silver nitrate in 95 to 100% yield. Diethyl carbonate‐13C or ‐14C was generated in 60 to 85% overall yield by treatment of labeled silver carbonate with ethyl iodide and tetraethylammonium iodide in dimethylformamide. The effects of alterations in reaction time, metal ion, solvent and catalyst were investigated.
Synthesis of 14C‐labeled antitumor agents. I. Synthesis of the ring‐ and side‐chain‐14C‐labeled DL‐4,4′‐propylenedi‐2,6‐piperazinediones
Authors: Lin Ying‐Tsung , Leaffer M. A. , Tanabe Masato 
Published: October 2006

AbstractThe ring‐ and side‐chain‐14C‐labeled DL‐4,4′‐propylenedi‐2,6‐piperazinediones (I) were synthesized from chloroacetic acid‐1‐14C in two steps and from DL‐analine‐1‐14C in six steps, respectively. The radiochemical yield for the ring labeling was 24.5%; for the side‐chain labeling it was 13.7%. In the side‐chain labeling, the synthesis involved a new method for preparing DL‐proprylenediamine from DL‐alaninamide.
Synthesis of tritium labeled 1‐methyl‐4‐[4‐(7‐trifluoromethyl‐4‐quinolyl)‐aminobenzoyl]piperazine and derivatives
Authors: Hsi Richard S. P. 
Published: October 2006

AbstractDeuteration of p‐aminobenzoic acid hydrochloride (PAB·HCl) was studied to provide a model for tritiating PAB‐HCl. Tritium labeled PAB·HCl was used as the starting material for the synthesis of tritium labeled 1‐methyl‐4‐[4‐(7‐trifluoromethyl‐4‐quinolyl)aminobenzoyl]piperazine (Ic) and the corresponding 1‐demethyl compound (Id) and 1‐oxide (II).
Synthesis of carbon‐14 labeled 1,4‐benzodiazepines. III. 2‐allyloxy‐amino‐7‐chloro‐5‐(2‐chlorophenyl)‐3h‐l,4‐benzodiazepine‐2‐14C, 8‐chloro‐1‐dimethylamino‐methyl‐6‐phenyl‐4H‐s‐triazolo[4,3‐a][1,4]benzodiazepine‐3a‐14C, and 8‐chloro‐2,4‐dihydro‐2‐methyl‐6‐phenyl‐1H‐s‐triazolo[4,3‐a] [1,4]benzodiazepin‐l‐one‐3a‐14
Authors: Hsi Richard S. P. , Johnson Tommy D. 
Published: October 2006

AbstractA group of radioactive 1,4‐benzodiazepine derivatives have been synthesized from glycine‐1‐14C. The subject compounds are labeled with carbon‐14 in the 2‐position of the 1,4‐benzodiazepine ring system.
Synthese du chloro‐7 nitro‐4 benzooxa‐2 diazole‐1,3 uniformement marque au carbone‐14: Chlorure DE NBD‐14C (U) “chloro ‐ 4 nitro‐7 benzofurazane 14C (U)”
Authors: Noel Jean‐Pierre , Pichat Louis 
Published: October 2006

AbstractThe little compound, a useful reagent in biochemistry, has been synthasised in 14 steps from barium carbonate 14C via benzene 14C‐U, through aniline 14C‐U, p‐aminobenzene oulfamide 14C‐U and 2, 6 dichloroaniline 14 C(U). The axidation of the latter into 2,6 dichloronitrosobenzene 14 C(U) is best performed with m‐chloro peroxybenoic acid; other reagents reported in the literature give rise to substantial amounts of 2,6 dichloronitrobenzene 14 C‐U. Sodium axide and the 2,6 dichloronitrosobenzene 14 C(U) give p‐chlorobenzfurazane‐14 C(U). Nitration of the latter is conveniently obtained with the complex: trifluoromethan sulfonic acid + nitric acid which gives NBD, chloride 14 C(U) with a 96 % yield. The overall yield is 14% basen on Ba 14 CO3. Specific activity: 199 mci/mMoLe ‐ Schelf‐life at − 20°C, as liophilised power kept under vaccum, so for has been good.
The preparation of 2‐(4‐chlorophenyl)‐[2‐14C]thiazol‐4‐ylacetic acid [I.C.I. 54,450]
Authors: White D. F. , Burns J. 
Published: October 2006

AbstractThe preparation of 2‐(4‐chlorophenyl)‐[2‐14C]thiazol‐4‐ylacetic acid [I.C.I. 54,450] from potassium [14C] cyanide in six stages is described. The overall radioachemical yield of product, at a specific activity of 12.56 μCi/mg, was 22.2%.
Fluorine‐18 labelling of lower fatty acid esters by heterogeneous exchange on gas chromatographic columns
Authors: Karim H. M. A. , Stöcklin G. 
Published: October 2006

AbstractFluorine‐18 produced via the reaction chain 6Li(n,α)t, 16O(t,n) 18F by reactor irradiation of Li2CO3 was directly recovered in carrier‐free form with a 90% yield by repeated extractions with water. A simple apparatus was used for simultaneous extraction and fast loading of an exchange resin with 18F. Dowex 1×4 in the acetate form was found to be best suited for a gas phase 18F‐for‐Br exchange in α‐bromofatty acid esters. The 18F‐loaded exchange resin was brought into a gas chromatographic column followed by an analytical column for the separation of the 18F‐labelled product from the unchanged bromine compound. The dynamic technique combines synthesis and purification and allows a fast and carrier‐free production of 18F‐α‐fluorofatty acid esters with boiling points up to about 300 °C. α‐fluoroacetic acid ethyl ester and α‐fluorovaleric acid methyl ester have been labelled carrier‐free with yields of 64% (at 170 °C) and 39% (at 190 °C), respectively. Kinetic studies on the yield determining factors have also been carried out.
Preparation De Thiazolidines Deuteriees En Positions 2,3,4 et 5
Authors: Guiliano Michel , Mille Gilbert , Chouteau Jacques , Larice Jean‐Louis , Roggero Jean‐Pierre 
Published: October 2006

AbstractTwo methods of synthesis of thiazolidinic cycle without substituent have been tested. For the classic cysteamine‐formaldehyde reaction we have shown that it was possible to obtain thiazolidine without passing through a chlorydrate intermediate (yield 50–60%). For Bestian's method (ethyleneimine‐formaldehyde reaction followed by H2S saturation), we have generalized a mode of operation which was applied up to now to obtain thiazolidine substituted in position‐2 only.It's with the last method that we have prepared the 2,2 d2 thiazolidine, the 4,4,5,5 d4 thiazolidine and the 2,2,4,4,5,5 d6 thiazolidine. (Rating of deuteration upper than 95%).By exchange with with D2O in acid medium we have prepared the 2,2,3 d3 thiazolidine. (Rating of deuteration on nitrogen atom: 97%).
Tritiation of low molecular weight alkanes and alkenes by self‐radiation induced exchange with HTO
Authors: Long Mervyn A. , Garnett John L. , Meakin Christopher P. 
Published: October 2006

AbstractThe tritiation of a range of low molecular weight alkanes and alkenes has been investigated by self‐radiation induced exchange with HTO at room temperature and 115°. By comparison with the Wilzbach T2 gas exposure procedure, the HTO method yields less byproducts and radiochemical purification of the parent compound is facilitated. With alkenes, saturation of the double bond is a competing process in the HTO procedure, however the significance of this side reaction decreases with increasing temperature of exchange. The HTO technique is shown to be suitable for tritiating a wide range of hydrocarbons to medium levels of specific activity.
Synthesis of daunorubicin‐14‐14C and adriamycin‐14‐14C
Authors: Chen C. Rolland , Fon Mary Tan , Fujiwara Alan N. , Henry David W. , Leaffer Morris A. , Lee William W. , Smith Thomas H. 
Published: October 2006

AbstractReaction of adriamycinone with excess14CH3Mgl and periodate cleavage of the resulting glycol (5) affords daunomycinone‐14‐14C (6). Bromination and hydrolysis of 6 gives adriamycinone‐14‐14C (8). Coupling of 6 and the 14‐0‐p‐anisyldiphenyl‐methyl derivative (9) with 1‐chloro‐3‐N‐trifluoroacetyl‐4‐0‐p‐nitrobenzoyldau‐nosamine (10) affords daunorubicin‐14‐14C (1) and adriamycin‐14‐14C (2), respectively, after deprotection.
Tritium labelling of Thaumatin I, a sweet‐tasting protein from Thaumatococcus daniellii benth, by reductive methylation
Authors: van Der Wel H. , Wiersma A. , Brouwer J. N. 
Published: October 2006

AbstractThaumatin I has been labelled by reductive methylation of four of the ε‐amino groups of the lysine residues in the protein with tritiated sodium borohydride. Methylation with unlabelled sodium borohydride showed that up to seven amino groups can be methylated without loss of sweet‐ness intensity.The yield of the tritium‐labelled methylated Thaumatin I was 31% with a tritium incorporation of 4.7%. Its specific radioactivity was 12.8 Ci/mmol.
Synthesis of diethyl 1‐[(13C)methyl]‐3‐phenyl(1,3‐13C2)bicyclo[1.1.0]‐butane‐exo,exo‐2,4‐dicarboxylate
Authors: Pomerantz Martin , Fink Rina 
Published: October 2006

AbstractThe synthesis of the triply13C labeled molecule, diethyl 1‐[(13C)methyl]‐3‐Phenyl(1,3‐13C2)bicyclo[1.1.0]butane‐exo,exo‐2,4‐dicarboxylate is described. The unique feature of the synthesis is that in three instances we employed13CO2(from Ba13CO3) without using a high vacuum line. We found that excellent yields were obtained in two Grignard reagent carbonations and in a CO2reduction using a mechanical pump which produced a vacuum of 0.05 torr. The synthetic sequence involved carbonation of phenylmagnesium bromide to give (α‐13C)benzoic acid, reduction with LiAlH4, conversion to the corresponding benzyl chloride followed by preparation of the Grignard reagent and carbonation to produce phenyl (1,2,‐13C2)acetic acid. Reaction with13CH3Li provided 1‐Phenyl‐2‐(1,2,3‐13C3)‐propanone which, after conversion to its hydrazone and reaction with mercurous trifluoroacetate, yielded 1‐phenyl‐1‐(1,2,3‐13C3)propyne. Reaction twice with carboethoxycarbene (from ethyl diazoacetate) gave the desired triply13C labeled bicyclobutane.
Synthese De La Para‐aminoclonidine Tritiee : Un puissant alpha adrenomimetique
Authors: Rouot B. , Ehrhardt J. D. , Leclerc G. , Schwartz J. 
Published: October 2006

AbstractThe preparation of a tritium labelled alpha‐adrenergic agonist, 2‐(4‐amino‐2,6‐dichloro 3,5‐ditritio‐phenylimino)‐imidazolidine, suitable for alpha‐adrenergic receptor membrane binding studies, is described.
The synthesis of 123m Te‐labeled 17β ‐hydroxy‐2‐tellura‐A‐nor‐5α‐androstane
Authors: Knapp F. F. 
Published: October 2006

AbstractA microscale synthesis has been developed for the preparation of 17β‐hydroxy‐2‐tellura‐A‐nor‐5α‐androstane. Reactorproduced 123mTe has been used to prepare the 123mTe labeled steroid. The radiochemical synthesis and purification of this potential prostate imaging agent are described in detail.
Mit γ‐Emittern Markierte Steroide ‐ Ester des östradiols und cholestenols mit [103 Ru]‐ruthenocencarbon‐säure
Authors: Hoffmann K. , Rießelmann B. , Wenzel M. 
Published: October 2006

AbstractRadioactive esters of estradiol and cholestenol with ruthenocene‐carboxylic acid were prepared. In case of the estradiol esters there had been exchange of Fe in the corresponding ferrocene compounds with 103RuCl3 resulting in poor yield only. Good radiochemical yields were obtained by exchanging 103Ru for Fe in (2‐chlorobenzoyl)ferrocene and synthesis of the esters by reaction of estradiol with [103Ru] ruthenocenecarboxylic acid chloride generated from (2‐chlorobenzoyl)ruthenocene. High specific activities of estradiol esters for biochemical studies were achieved after separation of the ferrocene and ruthenocene esters by HPLC.
A study on the electrophilic iodination of chloroquine
Authors: Bakker C. N. M. , Kaspersen F. M. , van Langevelde A. , Oosterhuis J. A. , Pauwels E. K. J. 
Published: October 2006

AbstractChloroquine can be iodinated with radioactive iodine in radiochemical yields 60‐75% with chloramine‐T or H2O2/lactoperoxidase. With both methods a rather complex mixture of labelled products is formed. The yield and ratios of the labelled products depend upon the chloroquine‐concentration, the amount of carrier iodide present and in the case of the chloramine‐T method, the chloramine‐T concentration. With the chloramine‐T method the main product is 3‐iodochloroquine, with H2O2/lactoperoxidase an unidentified iodinated chloroquine‐derivative, probably a dimer, is the main labelled product. With chloramine‐T products such as 3‐chlorochloroquine and deethylchloroquine are formed in mass amounts.
Synthesis and characterization of 5‐methyl‐1‐phenyl‐3,4,5,6‐tetrahydro‐1H‐2,5‐benzoxazocine‐1,3,4,6‐13C hydrochloride (Nefopam‐13C hydrochloride)
Authors: Bunker James E. , Newmark Richard A. 
Published: October 2006

AbstractNefopam hydrochloride (I), an analgesic agent, was labelled with carbon‐13 at C‐1,3,4 and 6 positions for metabolic studies. The starting materials for the synthesis included commercially available phthalic acid‐carboxyl‐13C1 (II) and 2‐methylaminoethyl‐1,2‐13C2 alcohol. The extent of isotope enrichment was determined by nuclear magnetic resonance and mass spectroscopy. The overall yield of I was 34% from phthalic acid‐carboxyl‐13C.
Synthesis of 3‐indolyl(1‐14C)acetic, 3‐indolyl(2‐14C) acetic and 3‐indolyl(1,2‐14C2)acetic acids
Authors: Viswanathan K. V. , Ramaamurthy T. V. 
Published: October 2006

AbstractThe synthesis of 3‐indolylacetic acid labelled with 14C in side chain carbon atoms has been effected using (1‐14C)glycolic acid, (1,2‐14C2)glycolic acid and (2‐14C)glycolic acid in an yield of 40‐60%. Some of the parameters that affect the synthesis have been studied and the results are reported in this paper.
Synthesis of trans‐[13,14‐14C2]‐retinoic acid
Authors: Kaegi Heinz , Chew Edward , Chien Ping‐Lu 
Published: October 2006

AbstractTrans‐[13,14‐14C2]‐Retinoic acid has been synthesized by condensation of β‐ionylideneacetaldehyde and 14C‐labeled methyl senecioate in the presence of potassium amide in ether. A convenient synthesis of the key intermediate, methyl (diethoxyphosphinyl)‐[2‐14C]acetate, is also described.
The synthesis of pyrrole derivatives labelled with 13C in selected positions: Improved procedures
Authors: D'alessandro Giuliana. , Sleiter Giancarlo 
Published: October 2006

AbstractStarting from sodium acetate‐1‐13C or ‐2‐13C improved procedures for the preparation of ethyl acetoacetate‐2,4‐13C2, ethyl acetoacetate‐1,3‐13C2, ethyl acetoacetate‐2‐13C, and ethyl acetoacetate‐2,3‐13C2 are described. A method was also worked out which allows, using the labelled ethyl acetoacetates, to obtain Knorr's pyrrole (diethyl 3,5‐dimethyl pyrrole‐2,4‐dicarboxylate) carrying the label in well‐defined positions in excellent yields. An example is given of further transformation of Knorr's pyrrole.
Synthesis of indium‐111 mesoprotoporphyrin IX
Authors: Lee K. M. , Marshall A. G. 
Published: October 2006

AbstractIndium‐111 mesoprotoporphyrin IX has been prepared by refluxing suitable proportions of InCl3, sodium acetate, and mesoprotoporphyrin IX in glacial acetic acid. The labeled metalloporphyrin is sufficiently water‐soluble for use as a scanning agent, and can also be incorporated into heme apoproteins for perturbed gamma‐gamma angular correlation measurements.
14C‐labelling of optically active fenvalerate, α‐cyano‐3‐phenoxy‐benzyl (S)‐2‐(4‐chlorophenyl)‐3‐methylbutyrate (I)
Authors: Yoshitake Akira , Kanamaru Hiroshi , Shono Fumiaki , Nakatsuka Iwao 
Published: October 2006

Abstract(S)‐Fenvalerate (α‐cyano‐3‐phenoxybenzyl) (S)‐2‐(4‐chlorophenyl)‐3‐methylbutyrate, a novel insecticide, was labelled with carbon‐14 individually at the carbonyl (1a), the cyano (1b) and the alcoholic methyne (1c) carbons for use in metabolic studies. Isopropylation of 4‐chlorophenylacetonitrile‐14C with isopropyl bromide followed by hydrolysis gave racemic 2‐(4‐chlorophenyl)‐3‐methylbutyric‐1‐14C acid, which on optical resolution with (−)‐1‐phenylethylamine gave the (S)‐acid. Esterification of the (S)‐acid with α‐cyano‐3‐phenoxybenzyl bromide gave 1a in 18% yield from potassium cyanide‐14C. Esterification of α‐cyano‐14C‐3‐phenoxybenzyl alcohol with (S)‐2‐4‐chlorophenyl‐3‐methyl‐butanoyl chloride (9) gave 1b in 65% yield. Condensation of 3‐phenoxybenzaldehyde‐(carbonyl‐14C), prepared from 3‐phenoxybenzoic‐14 C acid, with 9 and sodium cyanide gave 1c in 54% yield from barium carbonate‐14C.
Synthesis of [1‐14C]n‐heptane
Authors: David G. G. , Morris D. F. C. , Short E. L. 
Published: October 2006

AbstractSynthesis of n‐heptane labelled with carbon‐14 in the 1‐position is described. The precedure involves five steps starting with reaction of [14C]carbon dioxide with n‐hexyl magnesium bromide and finishing with reduction of [1‐14C]n‐heptyl bromide. The purity of the final product was more than 97% and the overall yield was 36%.
The synthesis of aliphatic and aromatic hydrocarbons containing methyl groups labelled with 11C
Authors: Långstro̊m B. , Sjöberg S. 
Published: October 2006

AbstractThe synthesis of [1‐11C]pentane, [1‐11C]nonane, [1‐11C]‐ undecane, 2‐[11 C]methyl‐naphthalene and [11C]methyl‐benzene (toluene) are reported. The hydrocarbons were prepared by the coupling reaction between [11C]methyl iodide and the appropriate lithium organocuprate. Toluene was also labelled by the coupling reaction between phenyllithium and [11C]methyl iodide. The reactions were carried out in ether giving the 11C‐labelled hydrocarbons in radiochemical yields < 90% with short reaction times (3‐13 min). The overall synthetic time from [11C]carbon dioxide was 9–19 min.