摘要:

AbstractA simple and efficient procedure has been developed for the synthesis of [3H]monomethylethanolamine and [3H]dimethyl‐ethanolamine. Schiff base formation between formaldehyde and either ethanolamine or monomethylethanolamine was followed by Na B[3H]4reduction. The reaction products were obtained from preparative thin layer chromatography plate

ISSN:0362-4803    

DOI:10.1002/jlcr.2580270202

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

Abstract1‐Nitropyrene‐d9, 1,3‐dinitropyrene‐d8, 1,6‐dinitropyrene‐d8, and 1,8‐dinitropyrene‐d8, used as internal standards for the determination of nitropolycyclic aromatic hydrocarbons (NPAH) in simple and complex mixtures, and required for GC/MS measurements used in the certification of NBS Standard Reference Material (SRM) 1596 (a mixture of nitropyrenes), were synthesized in one step from commercially available pyrene‐d10and nitric acid‐d1. The electron impact mass spectra and isotopic purity of 1‐nitropyrene‐d9and the deuterated dinitropyrenes were determined; the compounds were characterized by gas chromatpgraphy‐mass spectrometry (GC‐MS) and by high performance l

ISSN:0362-4803    

DOI:10.1002/jlcr.2580270203

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

Abstract5‐[18F]Fluorouracil was prepared by direct fluorination of uracil in acetic acid using [18F]F2diluted in neon. The labelled product was obtained with a purity of ≥99% following preparative HPLC. Quality control consisted of two different and improved HPLC procedures combined with high resolution NMR spectroscopy for analyzing directly the HPLC elution peaks. A final formulation contained typically 4.8 · 108Bq 5‐[18F]fluorouracil with a specific activity of 1.14 · 10

ISSN:0362-4803    

DOI:10.1002/jlcr.2580270204

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractCarbon‐14 labeled paldimycin trisodium salt was prepared by addition of N‐acetyl‐L‐cysteine to [14C]paulomycin, the radioactive antibiotic produced by fermentation ofStreptomyces paulusin the presence of L‐methionine labeled with carbon‐14 in the S‐methyl group Carbon‐13 nuclear magnetic resonance (NMR) spectra of paulomycin produced when the fermentation was carried out in the presence of L‐[S‐methyl‐13C]methionine showed that isotope incorporation had occurred specifically at the methoxy group of ring C, i.e., the 2‐deoxy sugar portion of paulomycin. With sustained slow feed of labeled precursors during the optimum antibiotic production period, carbon‐14 isotope yields of up to 17.5% with specific activity of up to 11.4 μCi per milligram of paulomycin, and carbon‐13 isotope yields of up to 24% with 17‐fold isotope enrichment over na

ISSN:0362-4803    

DOI:10.1002/jlcr.2580270205

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

Abstract3‐Aminoxy‐1‐aminopropane (APA) has previously been shown to be a potent inhibitor of the polyamine biosynthesis enzymes ornithine decarboxylase, adenosylmethionine decarboxylase, and spermidine synthase. Little information is known, however, regarding its mechanism of action, binding site mode(s), or cellular distribution. This report presents a relatively simple three step synthesis of 3‐aminoxy‐1‐amino[1,1′‐3H2]propane via the catalytic tritiation of 3‐aminoxypropionitrile hydrochloride. The latter compound has previously been described in the literature, albeit in little detail, but is included in this repo

ISSN:0362-4803    

DOI:10.1002/jlcr.2580270206

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe synthesis of [14C]‐ and [2H]‐labeled LY253351 (YM12617–1), a potent α1‐receptor antagonist, which is potentially useful in the treatment of benign prostatic hypertrophy (BPH) is described. The [14C]‐isotopomer was synthesized from [14C]‐potassium cyanide in nine steps in 1.5% radiochemical yield. One of the key intermediates, [14C]‐4‐methoxyphenylacetone, was synthesized from [14C]‐4‐methoxyphenylacetyl chloride by a Pd(0)‐catalyzed reaction with tetramethylstannane. The [2H]‐labeled material was synthesized by a Pd/C catalyzed reductive amin

ISSN:0362-4803    

DOI:10.1002/jlcr.2580270207

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe tetradeuterated analogues of the 2‐methylsulfinyl (mesoridazine) and 2‐methylsulfonyl (sulforidazine) metabolites of (±)‐10‐[2‐(1‐methyl‐2‐piperidinyl)ethyl]‐2‐methylthio‐10H‐phenothiazine (thioridazine) were obtained by treatment of the appropriate 2‐substituted phenothiazine with the synthon, 2‐(2‐chloro[1,1,2,2‐2H4]‐ethyl)‐1‐methylpiperidine. Selective ring sulfur oxidation using nitrous acid of these deuterated products as well as the previously reported analogous isotopomer of thioridazine gave the tetradeuterated analogues of the 5‐sulfoxide metabolites of thio

ISSN:0362-4803    

DOI:10.1002/jlcr.2580270208

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractThe electrophilic radiobromination of m‐tyrosine was investigated and found to be rapid and quantitative. Two positional isomeric products were found by radio‐HPLC with a mass ratio of 4:1. Because of the inability of proton NMR to unequivocally identify the major product,13C‐NMR analysis was performed. Results show that the major product was 6‐bromo‐ D,L‐m‐tyrosine. Preliminary studies, in vivo, in mice suggest that radiobrominated m‐tyrosine is a potential tracer f

ISSN:0362-4803    

DOI:10.1002/jlcr.2580270209

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

Abstract3′‐O‐Acetylthymidine (1) was converted to the β‐acetoxy aldehyde (3) using a modified Swern oxidation procedure. The crude product was reduced with sodium borodeuteride to give, after chromatography, [5′‐2H]‐3′‐O‐acetylthymidine (4) in 68% overall yield from1. The extent of deuterium incorporation was>95% as judged b

ISSN:0362-4803    

DOI:10.1002/jlcr.2580270210

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY

摘要:

AbstractMethods are described for the synthesis of C [2H4]‐2‐bromo‐ethanol, [1‐2H2]‐2‐bromoethanol, [2‐2H2]‐2‐bromoethanol, [2H3]‐acrylonitrile and [2H3]‐acrylamide from 2‐benzyloxyacetic acid. In the synthesis of [1‐2H2]‐1‐bromo‐2‐chloroethane and [2‐2H2]‐1‐bromo‐2‐chloroethane from chloroacetonitrileviadeuterated 2‐aminoethanol and [1‐2H2]‐2‐bromoethylamine hydrobromide or [2‐2H2]‐2‐bromoethylamine hydrobromide some randomisation of the halogens occurred, and difficulties

ISSN:0362-4803    

DOI:10.1002/jlcr.2580270211

出版商:John Wiley&Sons, Ltd.    

年代:1989

数据来源: WILEY