摘要:

Abstract(2RS)‐[3‐13C]‐ and (2RS)‐[3‐14C] Leucine have been preparedviacarbonation of the Grignard reagent 2 from 2‐bromopropane, with13CO2or14CO2. Reduction of the labelled isobutyric acid, displacement of the derived isobutyl brosylate5with acetamidomalonic ester and hydrolysis afforded (2RS)–[3‐*C] leucine with 55–65% incorporation of label from Ba*CO3on a s

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210502

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractA 15.7 mCi sample of 99% radiochemically pure 1‐cyano‐1‐(6‐phenoxy‐2‐pyridinyl‐2,6‐14C)methyl 3‐(2,2‐dichloroethenyl)‐2,2‐dimethylcyclopropanecarboxylate with a specific activity of 21.3 mCi/mmole was preparedviaa six step process from 2,6

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210503

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractThe title work proceeds in five steps and 16% overall yield from sodium [1‐14C]acetate, which was converted by bromination followed by ethoxide displacement and reaction with phthaloyl dichloride to ethoxy[1‐14C]acetyl chloride. The thermal[2+2]cycloaddition of tetraethoxyethene with ethoxy[1‐14C]ketene, derived from base induced elimination from ethoxy[1‐14]acetyl chloride following the method of Bellus, provided an 80% yield of 1‐(ethoxy[1‐14C]acetoxy)‐2,3,3,4,4‐pentaethoxy‐l‐[1‐14C]‐cyclobutene. Acid hydrolysis and liquid‐liquid extraction a

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210504

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractAn investigation of the use of an aryltrimethylsilane intermediate to obtainp‐[77Br]bromohippuric acid (12) was carried out. The silane intermediate,p‐trimethylsilylhippuric acid (11), was radiobrominated with carrier‐added and no‐carrier‐added levels of bromine‐77 to give isolated yields of 73% and 49% of 12 (respectively). Initial radiobromination studies were carried out withp‐trimethylsilylbenzoic acid (1) to evaluate the feasability of the approach. Radiobrominations of1yielded 70–93% radiolabeling efficiencies. All of the radiobrominations could be accomplished within 15 minutes, indicating that the method could be applicable to use of the shorter lived radionucl

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210505

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

Abstract14C‐Ochratoxin A is obtained by coupling the N‐hydroxy‐succinimide derivative of the lactone acid hydrolysate of natural ochratoxin A with14C‐L‐β‐phenylalanine methylester.14C‐Ochratoxin A methylester is converted into14C‐ochratoxin A by alkaline hydrolysis. Purification of the intermediates and the14C‐ochratoxin A is achieved by HPLC. For an amount of 0.05 μmole L‐β‐phenylalanine methylester the yield of ochratoxin A is 0.02 μmole or 40% and the specific activity 130 Ci/mole. Stereospecificity is 100% and radiochemical purity is 96%.The yield of14C‐ochratoxin A increases with increasing amounts of14C‐L‐β‐phenylalanine methylester and rea

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210506

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractA new potent neuroleptic agent YM‐09151‐2, N‐[(2RS, 3RS)‐1‐benzyl‐2‐methyl‐3‐pyrrolidinyl]‐5‐chloro‐2‐methoxy‐4‐ (methylamino) benzamide (10c), was labeled with carbon‐14 and deuterium for biochemical studies such as metabolism and 14 pharmacokinetics. The synthesis of [carbonyl‐14C]YM‐09151‐2 (10a) from 4‐amino‐2‐hydroxy‐[carboxyl‐14C] benzoic acid (1a) in six stages is described. Overall radiochemical yield was 79.1% at a specific activity of 21.18 mCi/mmol. (Methoxy‐d3)YM‐09151‐2 (10b) was prepared from methyl 2‐(methoxy‐d3)‐4‐(N‐methyl‐N‐tosylamido) benzoate (5b) which was obtained by the reaction of methyl 2‐hydroxy‐4‐(N‐methyl‐N‐tosylamido) benz

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210507

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

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−1or 10 GBq mmol−1for 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%

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210508

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractSamples of 2,4‐diamino‐6‐methylpteridine (1), specifically labelled with13C at one or more carbon positions, were synthesised using a combination of the appropriate unlabelled and the following13C‐labelled starting materials (ca.90%13C): acetone‐2‐13C, acetone‐1,3‐13C, bromoacetic acid‐1‐13C, bromoacetic acid‐2‐13C, sodium cyanide‐13C, and guanidine‐13C. The identity and site(s) of13C of each final product and intermediate were

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210509

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

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 CS2at<0.05% (v/v) of the COS concentrati

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210510

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

Abstract3‐Methyl‐6‐[3‐(trifluoromethyl)phenyl]‐1,2,4‐triazolo[4,3‐b]pyridazine (4), currently being evaluated as a potential anxiolytic agent was synthesized, labeled with carbon‐14 in the 3‐position of the triazolo nucleus. The product was obtained in 67% radiochemical yield with specific activity of 13.5 mCi/mmol and radiopurity of greater than 99%. The carbon‐13 labeled compound was also synthesized for absorption and

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210511

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY