摘要:

Abstract3H‐Labelled ubenimex, N‐ (2S,3R)‐3‐amino‐2‐hydroxy‐4‐(o‐3H)phenylbutyrl)‐S‐leucine with a specific radioactivity of 15 mCi/mg was synthesized by a one step catalytic tritiation of N‐ ((2S,3R)‐3‐benzyloxycarbonylamino‐2‐hydroxy‐4‐(o‐bromo)phenylbutyryl)‐S‐leucine benzyl ester previously isolated from a mixture of four optical isomers using preparative high performance liquid chromatography.Chemical and radiochemical purities were over 99% as determined by thin layer chromatography and high performance liquid chromatography using radioisotope detection. By gas chromatography‐mass spectrometric analysis of deuterated ubenimex, the3H‐la

ISSN:0362-4803    

DOI:10.1002/jlcr.2580251202

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

Abstract[14C]Ciladopa (S(−)‐2‐[4‐[[2‐14C]‐2‐hydroxy‐2‐(3,4‐dimethoxyphenyl)ethyl]‐1‐piperazinyl]‐2,4,6‐cycloheptatrien‐1‐ one hydrochloride; AY‐27,110 hydrochloride) has been synthesized in six steps incorporating [14C]carbon dioxide. [7‐14C]Acetoveratrole, obtained from veratric acid via the acid chloride, was brominated and coupled with a troponylpiperazine salt. The resulting ketone was stereospecifically reduced microbiologically to give the S(−) enantiomer of the corresponding alcohol. Two batches of [14C]ciladopa were produced, giving a combined overall yield of 25% from [14C]barium carbonate (sp. act. 44.7 ± 0.6 and 43.4 ± 0.8 μCi/mg; 99.2 and 98

ISSN:0362-4803    

DOI:10.1002/jlcr.2580251203

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractA synthetic procedure for acetaminophen‐d4(4′‐hydroxyacetanilide – 2′,3′,5′,6′‐d4) is described. The preparation was achieved in two steps from nitrobenzene‐d5in an o

ISSN:0362-4803    

DOI:10.1002/jlcr.2580251204

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractA synthetic procedure for [3H]ciprofibrate is described. The radiolabel was introduced by catalytic dehalogenation of bromociprofibrate with tritium gas, as shown in the Scheme.

ISSN:0362-4803    

DOI:10.1002/jlcr.2580251205

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe reaction of [14C]CO2, generated from [14C]BaCO3, with dilithio propiolate (2) at −78°C afforded [1‐14C]‐2‐butynedioic acid (3) Reduction of3with platinum oxide and hydrogen gas gave [1‐14C]‐succinic acid (4) in 74% overall radiochemical yield from [14C]BaCO3with a specific activity of 55.4 mCi/mmol (2.05 GBq/mmol). Reaction of4with dichloromethyl methyl ether in the presence of zinc chloride yielded [1‐14C]‐succinyl chloride (5, 97.5% radi

ISSN:0362-4803    

DOI:10.1002/jlcr.2580251206

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractPreparation of three forms of selectively deuterated trans‐octaethylchlorin (t‐OEC) and octaethylporphyrin‐d2(OEP‐d2) with high isotopic purity using acid catalyzed hydrogen‐deuterium exchange reaction is described. Deuterated t‐OEC labeled at γ,δ‐methine carbons was prepared directly by equilibrating t‐OEC in D2SO4:D2O (6:1, v/v) at room temperature for 20 hours. t‐OEC labeled at all four methine carbons was prepared as above in 72 hours. And t‐OEC labeled at α,β‐positions was obtained by “back‐exchange” of t‐OEC‐d4under the protio condition, H2SO4:H2O (6:1, v/v), in 18 hours. The DDQ dehydrogenation of either dideuterochlorin species resulted in the formation of OEP‐d2. The isotopic purities of all deuterated compounds were over 98 percent except for t‐OEC‐d2(α,β) which was estimated to

ISSN:0362-4803    

DOI:10.1002/jlcr.2580251207

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe compound 6‐chloro‐2,3,4,5‐tetrahydro‐3‐methyl‐1H‐3‐benzazepine (SK&F 86466) was prepared in phenyl‐U‐14C and phenyl‐13C6labeled forms in a six step sequence beginning with the appropriately labeled benzenes. In addition, the N‐desmethyl analog of the carbon‐14 labeled isotopomer and the N‐methyl‐2H3derivative of the carbon‐13 isotopomer were prepared via the N‐(2,2,2‐trichloroethyl) carbamates by hydrolysis and lithium aluminu

ISSN:0362-4803    

DOI:10.1002/jlcr.2580251208

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractA method was devised for the synthesis of 3′,5′‐[2H2]folic acid (d2‐folic acid) for use in studies of folate metabolism in human beings. Labeling was accomplished by catalytic dehalogenation of 3′,5′‐dibromofolate with deuterium gas and palladium/carbon catalyst. d2‐Folic acid was separated from reduced forms and residual 3′‐monobromofolate by chromatography on DEAE‐Sephadex. Analysis by proton NMR and mass spectrometry indicated 70–75% deuteration of the 3′,5′‐positions and lack of

ISSN:0362-4803    

DOI:10.1002/jlcr.2580251209

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractMethods are described for tritiating compounds containing both chlorine or a double bond and bromine by highly‐selective debromination to give the chlorine‐containing or unsaturated3H‐compounds with specific activities of 10–28

ISSN:0362-4803    

DOI:10.1002/jlcr.2580251210

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY

摘要:

AbstractThe title compound has been prepared by two different approaches. The first involved a five‐stage “hot” synthesis where the tritiation step was selective debromination of a cyclic β‐bromo‐α‐β‐unsaturated ketone. The double bond was protected by formal aromatisation. The absolute structure of this intermediate was determined by3H‐FTNMR spectroscopy of its reduction product. Cadralazine was also labelled in its side chain by reduction of the appropriate ketone with high specific activity sodium borotritide. Both labelled products had specific activities of 18 Ci/mmol and radiochemical

ISSN:0362-4803    

DOI:10.1002/jlcr.2580251211

出版商:John Wiley&Sons, Ltd.    

年代:1988

数据来源: WILEY