ISSN:0362-4803    

DOI:10.1002/jlcr.2580310102

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractN.N‐Dimethyl‐[β‐(3,4‐Diacetoxy‐6‐123I‐Iodophenyl)]ethylamine (IDDE) was synthesized by the iododemercuration reaction with [123I]‐NaI and Chloramine‐T. The iodinated compound was deprotected with BBr3, acetylated and purified by HPLC to give the final product in 43% radiochemical yield. The radiochemi

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310103

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractIn order to corroborate a mechanisms proposed for the fragmentation of the molecular ion of heterosides, involving a hydride migration from the aglycome to the osidic unit, the 4‐[2H2]‐10‐[2H3]‐labelled neryl and geranyl‐β‐D‐glucosides9and10have been synthesised.Deuterated ketone1was prepared in>99% isotopic abundance by base catalysed exchange with [2H2]‐water, and was reacted under Wittig‐Horner conditions furnishing the corresponding α, β‐unsaturated esters3and4.Selective reduction of the ester group can be performed with DIBAl‐H, whereas LiAlH4give a secondary reduction of the CC double bond.The published procedure (13) for the β‐D‐glucosidation of alochols has been modified in order to optimise conditions on the deuterated nerol and geraniol.By comparison of collision spectra (NICI/CAD) of pure deuterated and undeuterated neryl and geranyl‐β‐D‐glucosides the proposed fragmen

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310104

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

Abstract(+)‐S‐145 and S‐1452, thromboxane A2receptor antagonists, were labelled with3H and14C for studies on the metabolic fate and characterization of receptor binding.3H and14C were incorporated into the benzene ring in the phenysulfonylamide side chain with specific radioactivities of 26.4 Ci/mmol and 8.73 mCi/mmol, respectively. The common key intermediate, amine12awas synthesized in eight steps from4afor facile labe

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310105

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

Abstract3‐O‐Methyl‐2‐ and 6‐[18F]‐fluorodopa were synthesized in 8% radiochemical yield by the direct fluorination of a protected L‐dopa derivative with [18F]‐acetyl hypofluorite. The 2‐ and 6‐fluoro isomers were separated and purified by

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310106

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe high‐affinity muscarinic receptor antagonist (R,R) I‐QNB(1)[(R)‐(‐)‐1‐Azabicyclo [2.2.2]oct‐3‐yl‐ (R) ‐ (+) ‐α‐hydroxy‐α‐(4‐[127I]iodophenyl)‐α‐phenyl Acetate (6a)] has been labeled with iodine‐123 to give a suitable ligand for SPECT (Single photon emission computed tomography) imaging of the human brain. The radiolabeling is achieved using a copper(I) assisted nucleophilic exchange mechanism(2)to give high specific activity (R,R)123I‐QNB in reasonable overall yield (36%). The radiolabeling reaction is carried out in the presence of excess reducing agent and the product (R,R)123I‐QNB purified on a Sep‐Pak cartridge eliminating the need for h.p.l.c. purification the synthesis of the precursor (127I‐QNB) for the radiolabeling step is a modification of the procedure reported by Rzeszotarskiet. al(3)(R)‐α‐Hydroxy‐α‐(4‐nitrophenyl)‐α‐phenylacetic acid was produced from 4‐nitrobenzophenone and resolved as reported. The methyl ester of the acid was synthesised then the nitro group converted to an amino group to give Methyl, (R) ‐α‐hydroxy‐α‐ (4‐aminophenyl) ‐a‐ phenyl acetate. The iodo compound Methyl, (R) ‐α‐hydroxy‐α‐ (4‐iodophenyl)‐α‐phenyl acetate was produced from the amino compound via the diazonium salt. Transesterification of the iodo compound with (R) ‐3‐quinuclidinof gave (R, R) ‐f271‐QNB.The (R,R) 123I‐QNB pro

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310107

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe new ligands 1,6‐dimethoxy‐3,4‐hexanedione dioxime (DMHD) and 1,6‐diethoxy‐3,4‐hexanedione dioxime (DEHD) were synthesized and their boron containing99Tc/99mTc complexes, formed by reduction of pertechnetate with BH4‐, were isolated, purified and characterized by IR/UV/VIS spectroscopy and FAB mass spectrometry. These rather stable cationic complexes differ significantly in lipophilicity as assessed by their octanol/saline partition coefficients and HPLC capacity factors. Unexpectedly the organ uptake and clearance of both complexes in mice proved to be very similar with only the uptake of99mTc‐DMHD in the kidneys

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310108

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe solid‐state catalytic hydrogenation (SCH) of unsaturated precursor compound and the high‐temperature solid‐state catalytic isotope exchange (HSCIE) showed that the total incorporation of isotope and its distribution between the α‐and β‐positions of the alanine molecule can be modified by changing the temperature of solid state reactions. Tritium incorporation at high‐temperatures proceeds in a manner which retains the configuration of the asymmetric α‐carbone atom.3H NMR analysis of tritiated isotopomers was used for the investigation of solid‐state reactions. The HSCIE reaction proceeds selectively at 140 °C and only part of the molecules is in the the tritium spillover reaction zone. At 220°C HSCIE proceeds evenly along the whole mass to give unifor

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310109

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310110

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310111

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY