摘要:

AbstractThree major DDD isomers, o,p'‐DDD, m,p'‐DDD and p,p'‐DDD,14C‐labelled in thepara‐chlorophenyl ring, have been synthesized. The DDD products were obtained in isotopic yields ranging from 42% to 58% and were of high specific activities; 31 mCi/mmol (o,p'‐DDD; m,p'‐DDD) and 19,8 mCi/mmol (p,p'‐DDD). A minor amount of14C‐labelled o,m'‐DDD was also isolated. 400 MHz1H NMR data of the three major DDD isomers and o,m

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240902

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

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) with14CH3I. Also described is the synthesis of the optica

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240903

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThis systematic study describes the preparation of bifunctional n.c.a.18F‐fluoroalkanes using amino‐polyether (APE) supported nucleophilic substitution. With the APE (Kryptofix®2.2.2.) potassium carbonate complex in acetonitrile n.c.a.18F−is introduced into disubstituted alkanes ( X(CH2)nX, n = 1–3, X = Br, OMes, OTos) in high yields within 10–15 min. The substitution yield increases in the sequence of leaving groups Br

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240904

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractA short, efficient synthesis for [methoxy‐14C]eugenol from unlabelled eugenol is described. The free phenolic group is protected as a methanesulfonate ester prior to removal of the methoxyl group. Reaction of the resulting phenolic mesylate with [14C]methyl iodide under basic conditions followed by treatment with warm sodium hydroxide gave the title compound in good overall yiel

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240905

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractA procedure for labelling the novel analgesic, meptazinol [(+)1‐methyl‐3‐ethyl‐3‐(m‐hydroxyphenyl)tetrahydroazepine], with the positron‐emitting radionuclide, carbon‐11 (t1/2= 20.4 min) has been developed in order to permit the pharmacokinetics of this analgesic to be studied in man. The procedure involves the reaction of [11C]iodomethane, itself produced from cyclotron‐produced [11C]carbon dioxide, with normeptazinol in ethanol at 100°C for 5 min, evaporation of any unreacted [11C]iodomethane, purification by HPLC and removal of solvent. Subsequent solubilisation of the radioactive product in ethanol plus isotonic saline and sterilisation by filtration produces a safely‐injectable solution of [N‐methyl‐11C]meptazinol in 14% radiochemical yield (from cyclotron‐produced [11C]carbon dioxide, decay‐corrected). The specific activity of the product is up to 7.4 GBq/μmol at the end of radiosynthesis (40 min from the end of radionuclide production). Preparations have been shown to be radiochemically pure and to be free of normeptazinol by analytical HPLC and TLC. That the radioactive product is [N‐methyl‐11C]meptazinol has been unequivocally demonstrated by co‐inclusion of13C‐enriched iodomethane in the radiosynthesis and examination of the product by broad‐band proton‐decoup

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240906

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractIodine‐125 labeled analog of 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) was obtained by heating the iodine substituted analog of TPA in acetone with sodium [125I] iodide. The iodine substituted analog of TPA, 12‐O‐(12′‐iodododecanoyl)phorbol‐13‐acetate (IPA), was synthesized from phorbol by a three step reaction sequence. The structure of IPA was confirmed by high resolution proton magnetic resonance, fast atom bombardment mass spectrometry (FAB) and chemical ionization mass spectrometry (CIMS).The [125I]‐IPA was purified by normal phase flash column chromatography. The product had 99% radiochemical purity and specific act

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240907

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe title compounds (6and9) were prepared by exchange of the α‐protons of (E,E)‐2,4,‐heptadienyldiphenylphosphine oxide (2) with either2H2O or3H2O, followed by condensations with (E,E)‐5‐[2,3‐bis(t‐butyldimethylsilyl) oxy]‐propoxy‐2,4‐pentadienal

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240908

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe synthesis of methyl [2‐13C‐2, 2‐d2]‐ and methyl [3‐13C‐3, 3‐d2]tetracosanoate is reported. The carbon‐13 was introduced by cyanation of 1‐bromodocosane and 1‐bromoheneicosane using 18‐crown‐6 ether and potassium [13C]cyanide in hexamethylphosphoramide. Cyanation reactions with carbon‐13 proceeded at better than 90% yield by this method. Triphasic catalysis was used to introduce the CN group in successive homologations of the labeled compounds. This method was found to be label‐sparing with typical yields being 95%. No scramblin

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240909

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractTrisodiumphosphono/14C/formate (TPF) has been prepared in high chemical and radiochemical purity by carboxylation of sodium‐di‐n‐butylphosphite with14CO2, subsequent alkylation with dimethyl‐sulfate to di‐n‐butylphosphonomethyl/14C/formate and dealkylation of the latter with aid of trimethylbromosilane and alkaline hydrolysis.Whereas in trisodiumphosphono/14C/formate the radioactive carbon has been observed to be stable in its position, the14C in sodium‐di‐n‐butyl‐phosphono/14C/formate may be quantitatively

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240910

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractGlycylglycyl‐L‐leucine and glycyl‐L‐leucine dispersed on silica‐alumina and supported Ni catalyst, were labeled with tritium by microwave discharge activation of tritium gas, as a model to study the optimum condition for labeling peptides and proteins. In the reaction, decreasing the tritium pressure and increasing the microwave power promote the formation of tritium ions and result in an increase in specific activity of the labeled product. The highest specific activity was achieved with the adsorbate molecules as a monolayer on support. Under similar conditions, amino acids glycine and L‐leucine were less efficiently labeled than the peptides. Tritium atoms generated by mercury photosensitization with a uv light were less effective for labeling than tritium ions. Impurities in tritium gas can adversely affect the degree of tritium incorporation

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240911

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY