摘要:

AbstractTert.‐Butyloxycarbonyl‐l‐14C‐glycyl‐L‐tryptophyl‐L‐methionyl‐L‐aspartyl‐L‐phenylalaninamide /I/, H‐l‐14C‐glycyl‐L‐tryptophyl‐L‐methionyl‐L‐aspartyl‐L‐phenyl‐ alaninamide /II/ and tert.‐butyloxycarbonyl‐l‐14C‐aminooxyacetyl‐L‐tryptophyl‐L‐methionyl‐L‐aspartyl‐L‐phenyl‐alaninamide /V/ of differ

ISSN:0362-4803    

DOI:10.1002/jlcr.2580190402

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractA procedure is described for incorporating tritium into the 3‐CH2side chain of synthanecine A, and preparing the carbamate, 2,3‐bis‐N‐ethylcarbamoyloxymethyl‐l‐methyl‐3‐pyrroline, a hepatotoxic pyrrolizidine alkaloid analogue. The pyrrolizidine amino alcohol, retronecine, can be tritium labelled i

ISSN:0362-4803    

DOI:10.1002/jlcr.2580190403

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe synthesis ofthreo‐dl‐methylphenidate (Ritalin®,1),threo‐dl‐p‐hydroxymethylphenidate (3),threo‐dl‐ritalinic acid (2), andthreo‐dl‐p‐hydroxyritalinic acid (4) with deuterium incorporated in the piperidine ring is described. These compounds were synthesized for use as internal standards for mass fragmentographic assays of methylphenidate and its metabolites. The synthetic scheme described resulted in less than 0.05%2H0in the piperidine ring in any

ISSN:0362-4803    

DOI:10.1002/jlcr.2580190404

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe synthesis of the specifically labelled versatile prostaglandin intermediate1bis described which involves the preparation of 2,2,3,3 (2H4)butyliodide6bvia homogenous catalytic deuteration of the acetylene4. Examples for the preparation of prostaglandins and extensive spectroscopic data are included.

ISSN:0362-4803    

DOI:10.1002/jlcr.2580190405

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe preparation of tritiated tamoxifen generally labelled, and also specifically labelled in two separate positions is described. The generally tritiated material was prepared by an acid catalysed exchange reaction which produced labelled material of low molar specific activity [4.7 mCi/mmol].Both specifically tritiated products were derived from tritium labelled intermediates which were used in synthetic procedures to produce tritiated tamoxifen. [G‐3H]Bromobenzene was used to incorporate the label in the 1‐phenyl ring, and tamoxifen with a specific activity of 401 mCi/mmol was obtained. The reductive tritiation of a 3, 5‐dibromo precursor and subsequent synthesis gave tamoxifen with a specific activity of 19.5 Curies/

ISSN:0362-4803    

DOI:10.1002/jlcr.2580190406

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractSelective incorporation of deuterium by platinum‐catalyzed exchange for six ribonucleosides and two 2′‐deoxyribonucleosides has been studied as a function of catalyst/substrate ratio, temperature, time and concentration. In addition to exchange of carbon‐bound hydrogens in purines, pyrimidines and pyrrolo[2,3‐d]‐pyrimidines, reactions involving D2‐saturated D2O as solvent were used to effect extensive exchange of ribose hydrogens, principally at C‐2′. Reduction‐exchange of uridine was used to prepare 5,6‐dihydrouridine‐5,5,6,6,‐d4, and 4‐amino‐5,6‐dihydro‐7‐(β‐D‐ribofuranosyl)pyrrolo[2,3‐d] pyrimidine‐2,5,5,6,6‐d5from tubercidin. Sites and extent of deuteration were determined by m

ISSN:0362-4803    

DOI:10.1002/jlcr.2580190407

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractCommercial (l)‐carnitine chloride was N‐demethylated by the action of sodium benzenemercaptide in warm N,N‐dimethylformamide. The product 4‐(N,N‐dimethylammonio)‐3‐hydroxybutanoic acid chloride salt was isolated in good yield by ion exchange chromatography. Methylation of the product by14C ‐iodomethane in dry methanol produced biologically active 4‐N‐ Me‐14C ‐(l)‐carnitine chloride of high specific ac

ISSN:0362-4803    

DOI:10.1002/jlcr.2580190408

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe synthesis of SL‐75.212 (BETAXOLOL) labelled with carbon 14 : 1‐[4‐(2‐cyclopropyl methoxyethyl‐[1‐14C]) phenoxy]‐3‐isopropul amino‐2‐propanol :13was achieved by a twelve step sequence from [14C] carbon dioxide.Carbonation with14CO2of the Grignard reagent1gave 4‐benzyloxy [carboxyl‐14C] benzoic acid:2(87 % yield).2was successively treated in diethyl ether solution with diazomethane and lithium aluminium hydride giving rise to [7‐14C] 4‐benzyloxybenzyl alcohol4(82 % yield). Alcohol4was transformed into the corresponding chloride 5 when exposed to thionylchloride in ether.5was condensed with NaCN in DMF to give the nitrile6which was hydrolysed into the acid7isolated in a 75% overall yield from Ba14CO3.7gave the alcohol9by successive treatments with diazomethane and LiAlH4in ether.9with NaH gave the corresponding alkoxide which when condensed with bromomethylcyclopropane gave the ether10purified by silicagel column chromatography and isolated with an overall yield of 71 % from Ba14CO3. Hydrogenolysis of10gave the phenol11. The epoxide12was secured by condensation with epichlorhydrin in presence of NaOH. After purification by silicagel column chromatography10was opened with isopropylamine leading to the target compound BETAXOLOL13isolated as the hydrochloride. After extensive purification by Sephadex G‐10 column chromatography, SL 75.212 [ethyl‐1‐14C] was obtained in an overall yield of 26% from barium [14C] carbonate and a radiochemical purity better than 99%

ISSN:0362-4803    

DOI:10.1002/jlcr.2580190409

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractSix deuterated androstanediols were synthetised. The position of deuterium atoms on the molecule were checked by mass spectrometry and1H or13c nuclear magnetic resonance. The per cent of d0, d1,… dn‐molecules were calculated.The use of such labelled molecules in the fields of isotopic dilution‐mass fragmentography as carriers and/or internal standards is disc

ISSN:0362-4803    

DOI:10.1002/jlcr.2580190410

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY

摘要:

AbstractThe work presented illustrates a practical sequence requiring relatively simple and inexpensive aoparatus, and using the commercially available isotopic sources, to produce L‐alanine from M+3 (13C2,15N) to M+12 (13C3,15N, D4,18O2

ISSN:0362-4803    

DOI:10.1002/jlcr.2580190411

出版商:John Wiley&Sons, Ltd.    

年代:1982

数据来源: WILEY