摘要:

AbstractOlaquindox is a new feed additive.[14C]Olaquindox, labelled in different positions, was needed for tracer‐studies of pharmacokinetics, biotransformation and residues in several species of animals.2‐ [N‐(2‐hydroxethyl)‐carbamoyl] −3‐methyl‐[3‐14C] quinoxaline‐1,4‐dioxide ([3‐14C]Olaquindox) was synthesized from barium[14C]carbonate (22 moles; 1.15 Ci) via[1‐14C]acetic acid, sodium[1‐14C] acetate, [1‐14C] acetylchloride, ethyl [3‐14C] acetoacetate and 2‐carbethoxy‐3‐methyl‐[3‐14C] quinoxaline‐1,4‐dioxide with an overall yield of 10%, based on barium[14C]carbonate. The radiochemical purity was better than 98% (tlc). The specific activities of three preparations were 10.5, 8.4 and 5.45 μCi/mg respectively.[phenyl‐U‐14C] Olaquindox was synthesized starting from [U‐14C] aniline (19.8 mmoles; 284.4 mCi). Intermediate products were N‐acetyl[U‐14C]aniline, 2‐nitro‐N‐acetyl[U‐14C] aniline, 2‐nitro[U‐14C] aniline and [U‐14C] benzofurazanoxide. The total yield was 50% as calculated for [U‐14C]aniline. At calibration samples of two preparations showed specific activities of 49.5 and 11.1 μCi/mg r

ISSN:0362-4803    

DOI:10.1002/jlcr.2580180402

出版商:John Wiley&Sons, Ltd.    

年代:1981

数据来源: WILEY

摘要:

AbstractA high yielding synthesis of 5,5‐dideuterocyclophosphamide is described which involves the base catalysed deuterium exchange of 3‐hydroxypropionitrile and subsequent medium pressure catalytic hydrogenation to yield 1‐amino‐2,2‐dideuteropropan‐3‐ol. This compound is condensed with N,N‐bis(2‐chloroethyl)‐phosphoramidic dichloride to yield pure 5,5‐dideuterocyclophosphamide which is readily isolated as a cr

ISSN:0362-4803    

DOI:10.1002/jlcr.2580180403

出版商:John Wiley&Sons, Ltd.    

年代:1981

数据来源: WILEY

摘要:

AbstractA method for preparing specifically labelled propoxylated trimethylolpropane polymers is described.

ISSN:0362-4803    

DOI:10.1002/jlcr.2580180404

出版商:John Wiley&Sons, Ltd.    

年代:1981

数据来源: WILEY

摘要:

Abstract11C‐labelling of methionine residues in a synthetic peptide via the preparation of the corresponding protected, pure homocysteine peptide has been investigated. Complete deprotection of the peptide and specific methylation of the homocysteine residue can be performed in one step in liquid ammonia. As a first application of this method the synthesis of the tripeptide, Z‐Gly‐L‐Hcy (Bzl)‐Gly‐O‐Bzl, and its conversion to Gly‐Met‐Gly and the corresponding labelled Gly‐([11C]‐methyl) ‐ Met‐Gly, is reported. Starting with the protected peptide the labelling was performed in 20 ± 5 min (starting with11CO2), yielding the labelled peptide in 92 ± 5 % radiochemical yield. Analyses and preparative LC ca

ISSN:0362-4803    

DOI:10.1002/jlcr.2580180405

出版商:John Wiley&Sons, Ltd.    

年代:1981

数据来源: WILEY

摘要:

Abstract2,3‐Dihydroxybenzoic acid‐(carboxyl‐14C) can be synthesized in high overall yield from commercially‐available 2,3‐dimethoxybenzoic acid. The synthetic route features the application of a Curtius rearrangement, the thermal decomposition of a carboxylic acid azide to an isocyanate. The method is suitable for the preparation of the title compound on both micro and semimic

ISSN:0362-4803    

DOI:10.1002/jlcr.2580180406

出版商:John Wiley&Sons, Ltd.    

年代:1981

数据来源: WILEY

摘要:

Abstract2′‐Amino‐4′ ‐fluoro‐4‐(4‐hydroxy‐4‐) (3‐trifluoromethylphenyl) ‐ piperidino‐2‐14Cbutyrophenone [ID‐4708‐ (piperidine‐14C]), a neuroleptic agent, was synthesized for use in metabolic studies. The synthesis was achieved by the reaction scheme shown in Fig. 1. 1‐Benzyl‐4‐piperidone‐2‐14C was prepared by Mannich reaction of paraformaldehyde‐14C with ethyl acryloylacetate and benzylamine, followed by treatment with hydrochloric acid, in 65% yield. Grignard reaction of the product with 3‐trifluoromethylphenyl‐magnesium bromide followed by hydrogenolysis gave 4‐hydroxy‐4‐(3‐trifluoromethylphenyl)piperidine‐2‐14C (8), which was condensed with 3‐(6‐fluoro‐2‐methyl‐3‐indolyl) propionic acid to give the 3‐indolylpropionylpiperidine‐14C (10). Conversion of10by reduction, oxidation and then hydrolysis led to ID‐4

ISSN:0362-4803    

DOI:10.1002/jlcr.2580180407

出版商:John Wiley&Sons, Ltd.    

年代:1981

数据来源: WILEY

摘要:

AbstractBoth 2,3,7,8‐ and 1,2,7,8‐ tetrachlorodibenzofuran ‐U14C, specific activity 57 mCi/mmol, have been obtained in low yield but at<98% purityviaPschorr cyclization ofo‐phenoxyaniline ‐U14C, chlorination of the resultant dibenzofuran and separation of the tetrachloro isomers by hplc. The lower yields obtained in the Pschorr cyclization of “hot”o‐phenoxyaniline in comparison with the “cold” material are postulated to result from enhanced homolytic relative to heterolytic cleavage of the “hot” diazonium ion leading to a “hot” free radical which polymerizes. The completely anomalous results observed in the attempted palladium acetate‐mediated cyclization of diphenyl ether‐ U14C are likewise interpreted in terms of the inter

ISSN:0362-4803    

DOI:10.1002/jlcr.2580180408

出版商:John Wiley&Sons, Ltd.    

年代:1981

数据来源: WILEY

摘要:

AbstractThe micro‐procedure involved interaction of benzene with phosphorus trichloride followed by addition of sulphur. Phenyl dichlorophosphine sulphide was condensed with methanol to form 0‐methyl phenylthiophosphono‐chloridate which was allowed to react with the sodium salt of 4‐bromo‐2,5‐dichlorophenol to yield leptophos [O‐(4‐bromo‐2,5‐dichlorophenyl) 0‐methyl phenyl phosphonothioate]. Five radioactive leptophos compounds were prepared by substituting the cold chemicals with the appropriate radioactive precursor (32PCl3, 1‐14C‐benzene,35S,14C‐methanol or tritiated

ISSN:0362-4803    

DOI:10.1002/jlcr.2580180409

出版商:John Wiley&Sons, Ltd.    

年代:1981

数据来源: WILEY

摘要:

AbstractCatechol‐U‐14C and hydroquinone‐U‐14C were prepared from phenol‐U‐14C by mononitration followed by chromatographic separation ofo‐ andp‐nitrophenol‐U‐14C. The nitrophenols were separately hydrogenated, and the resulting aminophenols were converted by diazotization followed by hydrolysis to the title diols. Phenol‐U‐14C was synthesized efficiently from benzene by nitration, reduction, diazotization and hydrolysis. A similar series of reactions beginning with benzene‐U‐13C gave phenol, catechol and hydroquinone containing mo

ISSN:0362-4803    

DOI:10.1002/jlcr.2580180410

出版商:John Wiley&Sons, Ltd.    

年代:1981

数据来源: WILEY

摘要:

AbstractThe addition of NaNO2to aqueous NH4TcO4yielded paramagnetic Tc complexes when reduced in HCl solutions. Similar or identical complexes are produced by reduction of NH4TcO4with hydroxyl amine in acidic, neutral, and basic solutions.

ISSN:0362-4803    

DOI:10.1002/jlcr.2580180411

出版商:John Wiley&Sons, Ltd.    

年代:1981

数据来源: WILEY