摘要:

AbstractTritium labeled isoxsuprine hydrochloride was required for drug metabolism studies in these laboratories. This compound was prepared specifically labeled with tritium in the 1‐position by the catalytic reduction of racemic β(R), γ(R)‐ and β(S), γ(S)‐p‐hydroxy‐α‐(1‐phenoxy‐2‐propylamino)‐propiophenone hy

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070402

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractMethyl groups bound to heterocyclic rings may, in certain circumstances, exchange hydrogen for deuterium. This exchange has been studied for alkyl or amino‐alkylpyrimidines in acid medium. The qualitative results obtained as a function of acidity, substituant location and temperature confirm the reaction mechanism proposed by Brown except in the case of amino‐2 dimethyl‐4, 6 pyrim

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070403

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractThe isolation of 6,8‐d2‐catechin/epicatechin 5,7,3′,4′‐tetramethyl ether from the cleavage of a methylated condensed procyanidin with D2O/dioxan resulted in an investigation of deuterium exchange in some related compounds under identical experimental conditions. In the absence of any acidic catalyst, a partial exchange was established in the majority of di‐ and trimethoxybenzenes when heated with D2O/dioxan (3:1) at 95° for 16 hr in Pyrex glass ampules; 1,3,5‐trimethoxybenzene was found to undergo a complete exchange of nuclear hydrogens under these mild conditions. Methylated flavonoids containing a reactive phloroglucinol system also exchanged both nuclear hydrogens at C6and C8with deuterium, but 5,7,3′,4′‐tetramethoxy‐2,3‐trans‐flavan‐3,4‐cis‐diol (2R: 3R

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070404

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractThe tetrachloropropenylium‐ion is proved as intermediate for the exchange of chlorine between 3H‐pentachloro‐1‐propene and AlCl3–(36Cl). The exchange is preferred on C‐3. Chlorine of trichloroacrolein is exchanged with HCl in H2SO4‐solution. —36Cl‐labelled C3‐compounds ha

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070405

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractOn hydrogenation of the 2,6‐bis(phenylhydrazone) of 2,6‐diketopimelic acid with carrier‐free tritium a very low specific activity was achieved, due to the labile C‐T‐bonds in the α‐positions. 2,6‐Diaminopimelic‐4−3H acid of spec. activity 790 mCi/mmole was obtained by catalytic dehydrohalogenation of 4‐chloro‐2,6‐diaminopimelic acid in 1N ammonia. A new, simple apparatus for catalytic trit

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070406

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractThe readily accessible pregna‐5,16‐dien‐3 β‐ol‐20‐one (1) was transformed into 3β‐acetoxy‐pregna‐5,17‐dien‐20‐isopropoxy‐16‐one (9). This compound was labelled by base‐catalyzed isotopic exchange and then reconverted into labelled pregna‐5,16‐dien‐3β‐ol‐20‐one (13). Hydrogenation of this last one furnished the title compound (14). The labelling extent in the 15α,15β and 21 positions was determined by

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070407

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractPurine polyribonucleotides were labeled with tritium in the 8‐position of the purine ring by heating in tritiated water. An increase in the time of reaction raises the specific activity of the products thus obtained. However under these conditions the degree of fragmentation of the polynucleotides also rise

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070408

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractThree isotopically enriched samples of ethylenimine [aziridine] have been prepared, namely, mixtures containing ca. 50% [2‐D]ethylenimine, 25% [2,2′‐D2]ethylenimine, and 25% parent molecule; 97% [15N]ethylenimine and 3% parent molecule; 64% [13C]ethylenimine and 36% parent molecule. Infrared gas spectra showed the samples (ca. 90 mg) to be of high chemical purity (>98 %). The preparations have been used successfully for high‐resolution microwave

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070409

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractSpecifically labelled phenylacetic acid and mandelic acid derivatives, metabolites of L‐Dopa, have been synthesized via the intermediary labelled benzyl alcohols, which were prepared by reduction of the methyl esters of the appropriate benzoic acids. The benzyl alcohols have been converted to the corresponding phenylacetonitriles via the intermediate chlorides and to the cyanohydrins via the intermediate aldehydes in yields significantly higher than previously reported. Overall radiochemical yields of the title compounds were in the order of 25% from14CO2and specific activities ranged from 4–10 mC/mmole. The collated procedures have general applicabil

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070410

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY

摘要:

AbstractInterest for the preparation of14C‐labeled 3,4,3′,4′‐tetrachloroazobenzene for metabolism studies was developed after recent reports indicated that soil micro‐organisms could transform some chlorinated aniline based herbicides into azobenzene compounds. The preparation of tetrachloroazobenzene was carried out in a three‐step synthesis starting with ring−14C‐3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea (Diuron) which was previously prepared in the laboratory. The overall product yield for the synthesis was estimated to be 33.6%, and the specific activity of the labeled

ISSN:0022-2135    

DOI:10.1002/jlcr.2590070411

出版商:John Wiley&Sons, Ltd.    

年代:1971

数据来源: WILEY