摘要:

AbstractTwo site specifically deuterated primaquines were prepared. 4′,4′‐Dideutero primaquine3was obtained from the corresponding dideutero alcohol which was prepared by the low temperature reduction of the ester compound4with lithium aluminium deuteride. 1′‐Deutero primaquine r was prepared by the reductive alkylation of 6‐methoxy‐8‐aminoquinoline with N‐(2‐oxopentyl)‐phthalimide in the presence of sodium cyanoborodeuteride followed by removal of protect

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210402

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractThis report describes the synthesis of various carbon‐13 enriched n‐alkylchlorosilanes with label in corporation at selective positions along the alkyl chains. Compounds which were prepared were:n‐nonyltrichlorosilane‐1‐13Cn‐dodecyltrichlorosilane‐4‐13Cn‐dodecyldimethylchlorosilane‐4‐13Cn‐tridecyltrichlorosilane‐12‐13n‐dodecyltrichlorosilane‐12‐13Cn

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210403

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractRadiolabeled 4‐hydroxycoumarin was synthesized on a microscale by condensing [U‐14C]phenol and malonic acid in the presence of anhydrous zinc chloride and phosphorus oxychloride. The yield was 14% on a 0.5 mmol scale at a specific activity of 107 μCi/

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210404

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

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 of9, the reaction product obtained was converted into [12′‐13C]all‐rac‐α

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210405

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

Abstract[1,4‐14C] Acetylthiomalic anhydride was prepared from [1,4‐14C]maleic anhydride and thioacetic acid. Removal of the acetyl group was achieved by sodium hydroxide hydrolysis and the resultant [1,4‐14C]thiomalic acid was extracted into ethyl acetate. Sodium [1,4‐14C]aurothiomalate was prepared by the reaction of gold(I) iodide with [1,4‐14C] thiomalic acid and precipitation of the sodium salt from alkaline solution by the addition of ethanol. The products were demonstrated to have a radiochemical purity of>98% by radio‐scanning of thin‐layer chromatograms and scintillation counting of segments of the

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210406

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

Abstract[18O]‐Chlorocarbonylsulfenyl chloride with an isotopic purity of 92% was prepared in three steps starting with the [18O]‐hydrolysis of 2‐ethyl‐1,3‐dioxolane to [18O]‐propanal, which was then converted to [18O]‐O‐1‐methylpropylS‐methyl dithiocarbonate, which was then chlorinated to give the title compound. Distilled yields for the three steps were 57%, 49%, a

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210407

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractA two step synthesis of dl‐glutamine‐2,5‐15N2is described. 2‐Oxapentanedioic acid was reacted with hydrazine sulfate‐15N2to yield 6‐carboxy‐(2H)‐pyridazin‐3‐one‐1,2‐15N2, which was then reduced with hydrogen over 10% Pd/C catalyst to dl‐glutamine‐2,5‐15N2. Gas chromatography of the trimethylsilylated derivative of the labeled glutamine was used to establish purity. Mass spectra for dl‐glutamine‐15N2, dl‐glutamine and their intermediates, 6‐carboxy‐(2H)‐pyridazin‐3‐one‐1,2‐15N2and 6‐carboxy‐(2H)‐p

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210408

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractPramiracetam hydrochloride,N‐[2‐[bis(1‐methylethyl)amino] ethyl]‐2‐oxo‐1‐pyrrolidineacetamide hydrochloride, CI‐879, a new potential clinically useful cognition activator, was labeled with14C. Bromoacetic‐2‐14C acid was converted to its ethyl ester which reacted with sodium 2‐pyrrolidinone to yield ethyl 2‐oxo‐1‐pyrrolidineacetate‐α‐14C acid. Treatment of the latter withN,N‐bis(1‐methylethyl)‐1,2‐ethanediamine gave pramiracetam free base which was subseque

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210409

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

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 the18O 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 from18O2gas 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 from18O2were 34% for [18O] phenol and 23% for 1‐[18

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210410

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

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 % abundanc

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210411

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY