摘要:

AbstractEight methyl N‐(1H‐benzimidazol‐2‐yl) carbamates with various 5‐substituents were synthesized, each13C‐enriched at carbon 2, and the carbonyl and methoxy carbons. Five were prepared by cyclization involving the appropriate 4‐substituted 1,2‐diaminobenzene (C6H5CO‐, CH3CH2CH2O‐, CH3CH2S‐, C6H5S‐ and CH3CH2CH2‐), and methyl‐13C N‐[imino(methylthio) methyl‐13C]carbamate‐13C or methyl N, N'‐bis(methoxy‐13C‐carbonyl‐13C)carbamimidothionate‐13C. The latter were prepared from commercially available13C‐enriched (91‐92 atom %) carbon tetrachloride, methanol, and thiourea. The remaining three (5‐substituents: C6H5CH(OH)‐, C6H5SO‐ and CH3CH2CH2SO‐) were prepared by side‐chain reduction or oxidation. The1H‐ and13C‐NMR, and the methane CI mass

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240802

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

Abstract10‐Deazaaminopterin (1) and 10‐Ethyl‐10‐deazaaminopterin (2) labeled uniformly with14C at the glutamate moiety were prepared by the following procedure. Uniformly labeled L‐glutamic acid was converted to its dimethyl ester (3). 4‐Amino‐4‐deoxy‐10‐deazapteroic acid (4) and 4‐amino‐4‐deoxy‐10‐ethyl‐10‐deazapteroic acid (5) were converted to their respective mixed anhydrides6and7with isobutylchloroformate. Reaction of6and7with labeled dimethyl‐L‐glutamate gave dimethyl‐10‐deazaaminopterin (8) and dimethyl 10‐ethyl‐10‐deazaaminopterin (9) respectively, which on mild alkaline hydrolysis gave the target compounds1and2in22‐25% yield, based

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240803

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractA new simple synthesis of the boar pheromone [5α, 6α‐3H]‐androst‐16‐en‐3‐one with a specific activity of about 50 Ci/mmol and a radiochemical purity>99%

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240804

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractEtomidate, (R)‐(+)‐ethyl‐1‐(1‐phenylethyl)‐1H‐imidazole‐5‐carboxylate, is a short‐acting hypnotic. A new synthesis, featuring optical resolution on a non‐radioactive precursor and introduction of the tritium label by reductive dehalogenation, is described.The title compound was obtained at a specific activity of 3.77. Ci/mmol and

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240805

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe synthesis of 1,2,3,4‐tetrahydrocarbazole‐9a‐13C and carbazole‐9a‐13Cviacyclohexanone‐1‐13C, prepared in turn from carbon dioxide‐13C and 1,5‐pentanedimagnesium bro

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240806

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractTritium‐ or14C‐labelled methyl iodide and ethyl iodide were used for alkylations of phenols and thiols. The reactions were performed in a two‐phase system with phase transfer catalysis at room temperature. Products of high specific activity were isolated in isotope yields ranging from 38% to

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240807

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractRadioactive labelled raclopride and its (R)‐isomer were prepared by O‐alkylation of the corresponding phenols with labelled methyl iodide. The syntheses of the two phenolic precursors from (R)‐ and (S)‐2‐aminomethyl‐1‐ethylpyrrolidine are described. Resolution of the racemic amine into the enantiomers was accomplished by fractional crystallization of the ditartrates. Coupling of the amines with 3,5‐dichloro‐2,6‐dimethoxybenzoyl chloride, followed by dealkylation, led to the diphenolic precursors. Mono‐alkylation of the corresponding precursor with [3H]methyl iodide furnished the potent dopamine‐D2ligand [3H]raclopride and its (R)‐isomer. [11C]Methyl iodide was prepared from [11C]carbon dioxide. Subsequent reaction with phenolic (S)‐precursor furnished [11C]raclopride which has been used in positron emission tomography (PET)

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240808

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractA direct method for selective deuteration of xanthone 1 employing the lithium salt of 1,3‐diaminopropane‐N, N, N',N'‐d4is described. Dibenzofuran is also found to be deuterated selectively under these condi

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240809

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe preparation of99mTc‐N(3,4,5‐triiodo)‐acetanilido‐iminodiacetate (99mTc‐TIIDA) is described. This new labeled compound was studied in normal experimental animals as well as in animals with depressed hepatobiliary excretion. The results were evaluated in comparison to99mTc‐bromotrimethyl IDA (99mTc‐MEBROFENIN) a technetium chelate already used in diagnosis, as well as to99mTc‐iodotrimethyl IDA (IODOFENIN) a recently reported agent and highly specific for the hepatobiliary system.99mTc‐TIIDA was totally excreted via the hepatocytes in healthy animals but proved less effective in animals with depressed hepato

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240810

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractFor pharmacokinetic and metabolism studies in laboratory animals, CGP 20376 labelled with carbon‐14 on the dithiocarbamoyl carbon atom in the side chain at 6‐position of the benzthiazolyl ring system and having a specific activity of 6.13 μCi/mg (2.35 mCi/mmol) was synthesized, in four steps, starting with potassium[14C]thiocyanate. At physiological pH (in vitro) [14C] CGP 20376 dissociated rapidly into its biologically active isothiocyanate precursor [14C] CGP 20308, indicating that it might behave as a pro

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240811

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY