摘要:

AbstractN‐[4‐[4‐(2‐Pyrimidinyl)‐1‐piperazinyl]butyl]bicyclo‐[2.2.1]heptane‐2,3‐di‐exo‐carboxyimide dihydrogen citrate (tandospirone), a novel anxiolytic agent, was labeled with carbon‐14 individually at the imido carbonyl group and the pyrimidinyl ring. The synthesis of carbonyl‐labeled tandospirone was achieved according to the scheme shown in Fig. 3. Diels‐Alder reaction of maleic anhydride (2) with cyclopentadiene (3) afforded theendoanhydride (4), which was transformed into the imide (5) by treating with ammonia water. Thermal isomerization of theendoimide (5) and subsequent chromatographic separation gave the pureexocompound (6). Catalytic hydrogenation of6followed by alkylation with 1,4‐dibromobutane (8) yielded the bromide (9a). Condensation of9awithN‐(2‐pyrimidinyl)piperazine (10a) followed by treatment of the resulting disubstituted piperazine (11a) with citric acid afforded [carbonyl‐14C]tandospirone (1a). The overall yield of1awas 22% from2.The similar method was applied to the synthesis of pyrimidinyl‐labeled tandospirone as shown in Fig. 4. Condensation of 2‐chloro[2‐14C]pyrimidine (12) with anhydrous piperazine gave the pyrimidinylpiperazine (10b).N‐alkylation of10bfollowed by treatment with citric acid afforded [pyrimidinyl‐2‐14C]tandospi

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310602

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractTwo types of multi‐labelled urocanic acids with stable isotopes,i.e., [3‐2H,1′,3′‐15N2]urocanic acid and [2,3,5′‐2H3,2′‐13C,1′,3′‐15N2]urocanic acid were synthesized by the enzymatic reaction ofDL‐[3,3‐2H2,1′,3′‐15N2]histidine orDL‐[2,3,3,5′‐2H4,2′‐13C,1′,3′‐15N2]histidine with histidine ammonia‐lyase (Pseudomonas fluorescens) at pH 9.0. The reaction ofDL‐[2,3,3,5′‐2H4,2′‐13C,1′,3′‐15N2]histidine was achieved in D2O buffer system (pD 9.0) to avoid the enzyme‐catalyzed hydrogen exchange at C‐5′ of the imidazole ring. The isotopic purities were demonstrated to be 94 atom%, based upon the ion intensities in the region of the molec

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310603

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

Abstract[14C]‐Sch 42427 was synthesized by two different methods, resulting in incorporation of the label in different parts of the molecule. In the first synthesis [benzyl‐α‐14C]‐Sch 42427 was synthesized in overall 1.7% yield via a 6 step procedure, using [14C]‐trimethyl sulphoxonium iodide as the source of label. The second synthesis gave rise to [SO2‐14CH3]‐Sch 42427, which was prepared via a 2 step procedure from [14C]‐sodium thiomethoxide. Radiochemical purities were greater than 99% for both batches, and analysis by chiral hplc failed to detect any of the undesire

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310604

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractCarbon‐14 labeled Gadoteridol, [1,4,7‐Tris(carboxymethyl)‐10‐(2‐hydroxy‐1‐[14C]propyl)‐1,4,7,10‐tetraazacyclododecanato]gadolinium, was prepared from 1‐[14C] propylene oxide in a total yield of 30.4% and a radiochemi

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310605

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractAmong the CCK‐B receptor agonists reported to date, the two modified peptides BC 264 and BC 254 display a high affinity and selectivity for this binding site and are highly protected from enzymatic degradation. Recently, we reported the biological properties of a tritiated analog of this agonist, [3H]pBC 264, which fullfils all the criteria required for in vitro as well as in vivo studies of the CCK‐B receptor. On the other hand, BC 254 displays a high affinity for the CCK‐B binding sites in the guinea‐pig (K1= 0.56 nM) while its affinity in the rat is more than 60‐fold lower, a difference which could be due to the occurrence of CCK‐B receptor subtypes. In the present paper, we report the synthesis of [3H]pBC 264 and of the new tritiated ligand [3H]pBC 254 using [3H] NPS (N‐succinimidyl[2,3‐3H]propionate) as labelling agent. These two probes have high specific activity (70–100 Ci/mmol) and will enable extensive studies of the CCK‐B receptor

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310606

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractEpoxides are known mutagenic and carcinogenic metabolites of alkenes. During current toxicological investigations in our laboratory, we have monitoredin vivoepoxide levels using gas chromatography/mass spectroscopy isotope dilution assays. These assays require the use of deuterated analogues for the expected epoxide metabolites. To determine whether butadiene monoepoxide is formedin vivofollowing inhalation of 1,3‐butadiene, deuterated butadiene monoepoxide, a compound that is not commercially available, was needed. To meet this need, we developed a method using monoperoxyphthalic acid to synthesize [d6]‐butadiene monoepoxide from [d6]‐1,3‐butadiene with a reaction time of 50 min and a 94

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310607

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractTheS‐enantiomer of γ‐[(4‐trifluoromethyl)phenoxy]benzenepropanamine‐[3‐14C] hydrochloride has been prepared in eight steps from acetophenone‐[carbonyl‐14C]. The key step in the synthesis involved the enantioselective reduction ofR‐2‐chloroacetophenone‐[1‐14C] with (‐)‐diisopinocampheylchloroborane in an 86.5% yield. The chlorohydrin was converted toR‐phenyloxirane‐[1‐14C], which was subsequently converted to the correspondingR‐cyanohydrin by reaction with TMS‐CN/CaO. Borane reduction and arylation, followed by salt formation yieldedS‐γ‐[(4‐trifluoromethyl)pheno

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310608

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractA simple one step synthesis of deuteriated vanillin from 3,4‐dihydroxybenzaldehyde and iodomethane‐d3in strongly basic medium is descri

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310609

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310610

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310601

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY