摘要:

AbstractBaclofen has been found to bind to receptors in the central nervous system that are specific for γ‐aminobutyric acid (GABA), a well known inhibitory neurotransmitter. This paper describes the synthesis of a radioiodinated analog of baclofen as part of an effort to develop receptor probes useful in single photon emission computed tomography. Preliminary biodistribution studies showed the radioiodinationed analog to be essentially stable to in vivo deiodination and have a distribution profile similar to that of baclof

ISSN:0362-4803    

DOI:10.1002/jlcr.2580280202

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractThe synthesis of the title compound (5) is described. Treatment of 4‐O‐(4,6‐ethylidene‐α‐D‐glucopyranosyl)‐4′‐demethyl‐4‐epipodophyllotoxin with sodium metaperiodate in acetonitrile formed the highly colored 4‐O‐(4,6‐ethylidene‐α‐D‐glucopyranosyl)‐3′,4′‐dioxo‐4‐epipodophyllotoxin (1). Hydrogenation using 10% palladium on carbon produced the 3′,4′‐dihydroxy compound (2). Protection of the 4′ hydroxy was achieved by benzylation (3). Treatment with excess [14C]methyl iodide under basic conditions introduced the label on the 3′ position (4). Deprotec

ISSN:0362-4803    

DOI:10.1002/jlcr.2580280203

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractEnantiomerically pure (2S,3R)‐3‐[(2‐carboxyethyl)thio]‐3‐[2‐(8‐phenyloctyl)phenyl]‐2‐hydroxy[2‐14C]propionic acid ([14C]SK&F 104353) was synthesized from methyl chloro[2‐14C]acetateviaa five step sequence. Darzens Condensation with 2‐(8‐phenyloctyl)benzaldehyde gave atransepoxy ester which underwent epoxide opening with methyl 3‐mercaptopropionate to furnish a pair of regioisomers. The desired isomer was isolated by subjecting the mixture to retroaldol cleavage conditions to remove the unwanted component. Subsequent optical resolution as a derivative of (S)‐proline and hydrolysis of the 2S,3R diastereomer afforded the title compound with a 5

ISSN:0362-4803    

DOI:10.1002/jlcr.2580280204

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractL‐6‐[123I]Iododopa was synthesized by the exchange of123I for bromine on L‐6‐bromodopa in buffer(pH 4) for 35 minutes at 97°C. The synthesis was complete in approximately 1 hour with a radiochemical yield of 50%, a specific activity of 65 Ci/mmol and a radiochemical purity of ≥95%. A non radioactive standard of L‐6‐iododopa was synthesized by the iododemercuration of a mercury‐dopa derivative using I2in chloroform. It was shown that L‐6‐[123I]iododopa accumulated in the rat striatum with striatum:whole brain ratio of 1.36 at 1 hour

ISSN:0362-4803    

DOI:10.1002/jlcr.2580280205

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractTritium‐labelled methyl farnesoate ([3H]‐MF, 6.6 Ci/mmol) was prepared from a tritiated allylic alcohol derivative by an efficient new one‐pot halogen exchange‐reductive dehalogenation sequence. The resulting [3H]‐MF was converted in three steps to a diazomethyl ketone analog, [3H]‐FDK, which can be used for the photoaffinity labelling of MF bindi

ISSN:0362-4803    

DOI:10.1002/jlcr.2580280206

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractMethylenecyclopropyllithium reacts with13C‐ or14C‐oxirane to give labeled 2‐(methylenecyclopropyl)ethanol, which may be converted in three steps to the corresponding coenzyme A thioesters of (methylenecyclopropyl)acetic

ISSN:0362-4803    

DOI:10.1002/jlcr.2580280207

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractA mixture of DL‐[2H6]myo‐inositol‐1‐ and ‐4‐phosphate and (meso)myo‐inositol‐2‐ and ‐5‐phosphate is readily prepared on a 100 milligram scale from the mixed isomers of di‐O‐cyclohexylidene‐[2H6]myo‐inositol by phosphorylation with tetrabenzylpyrophosphate. The deblocked [2H6]myo‐inositol monophosphate isomers are obtained where the relative amounts of racemicmyo‐inositol‐1‐phosphate ≥ ‐4‐phosphate ≥ ‐2‐phosphate ≥ ‐5‐phosphate. In addition a simple synthesis of DL‐myo‐inositol‐1‐phosphate was developed which was found to be

ISSN:0362-4803    

DOI:10.1002/jlcr.2580280208

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractA synthetic procedure for producing isotopically ω‐labelled fatty acids is described. The isotopic label is introduced by reducing an ω‐tosylate with either labelled sodium borohydride or labelled lithium dimethyl cu

ISSN:0362-4803    

DOI:10.1002/jlcr.2580280209

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

Abstract13C labelled (1,2 and 1,12) and perdeuterated derivatives of 2‐phenyl cyclododecanones, as precursors for labelled triplet flexible biradicals to probe magnetic isotope effects at the radical centers on the triplet decay dynamics, were synthesized. Isotopomers of 2‐phenylcyclododecanone‐13C2‐(1,2 and 1,12) were synthesized from cyclododecanone‐13C2‐(1,2) by dibromination, followed by phenylation with lithiumdiphenylcuprate. Cyclododecanone‐13C2‐(1,2) was obtained from 1, 10‐dibromodecane via the following sequence: (1) K13CN; (2) hydrolysis; (3) esterification; (4) acyloin condensation. Perdeuterio‐2‐phenyl cyclododecanone (95% isotopic purity) was prepared from unlabelled 2‐phenyl cyclododecanone by a substitution of deuterium for hydrogen by treatment with excess D2O, catalyzed with D2‐reduced Pt

ISSN:0362-4803    

DOI:10.1002/jlcr.2580280210

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY

摘要:

AbstractA one‐pot reaction scheme leading to14C‐labeled pargyline (N‐methyl‐N‐ propargylbenzylamine) where in the radioactive label from [14C]‐formaldehyde is synthetically incorporated into the methylene group of the propargyl side chain is described. Thus, [14C]‐formaldehyde (aqueous solution) is condensed in solvent dioxane with N‐methyl‐benzylamine andmono‐trimethylsilylacetylene in the presence of cupric acetate dihydrate at elevated temperatures (85–86°) for 24 hrs. The Mannich condensation product is then desilylated and the radiolabeled pargyline is purified by partitioning in ether from acid and base followed by flash chromatography, and isolated as the hydrochloride. The radioactive yield is 58%. This method should be generally applicable for the incorporation of radioactive label into the propargyl methylene group of other drugs containing

ISSN:0362-4803    

DOI:10.1002/jlcr.2580280211

出版商:John Wiley&Sons, Ltd.    

年代:1990

数据来源: WILEY