摘要:

AbstractA new method of synthesis of DL‐[7‐14C]indospicine and DL‐2‐amino‐[7‐14C]pimelic acid and their nonradioactive equivalents is reported. The combined radiochemical yield of both compounds, starting from potassium [14C]cyanide was 15.3%. Indospicine was isolated as the

ISSN:0362-4803    

DOI:10.1002/jlcr.2580241103

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe synthesis of3H ‐diosgenin,3H ‐esmilagenin and3H ‐tigogenin (three potential hypocholesterolemic agents) was accomplished by low pressure hydrogenation of commercial (Sigma D 1634) diosgenin with3H ‐gas. The mixture of3H materials obtained was separated by silica gel G‐60 column chromatography by use of a benzene: ethyl acetate (8:2 v/v) solution. Purification of each sapogenin was by TLC chrom

ISSN:0362-4803    

DOI:10.1002/jlcr.2580241104

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe title synthesis can readily be carried out on a 50 mg scale or more, starting with the 54/46mixtureofE‐ andZ‐5‐bromoalcohols obtained from the sodium borohydride reduction of the ketone. The key feature on which the synthesis dependes is the fact that theZ‐trimethylsilyl bromoether is reduced by zinc borohydride (and ‐deuteride) in benzene much faster than the

ISSN:0362-4803    

DOI:10.1002/jlcr.2580241105

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractSpecifically labelled L‐phenylalanines have been prepared using a variety of classical synthetic methods in combination with phenylalanine ammonia lyase (PAL) enzyme activity of the yeastRhodosporidiumtoruloidesATCC 10788 orRhodotorulaglutinisIFO 0559, respectively. Thus, L‐[2‐2H]phenyl‐[2‐2H]alanine (5) was formed from (E)‐[2,2′‐2H2]cinnamic acid and ammonia in 46% yield, whereas L‐phenyl‐[2‐13C,15N]alanine (9) was obtained from (E)‐[2‐13C]cinnamic acid in 45% overall yield using an 8.3‐fold excess of15NH4Cl and repeating the reaction after recovery of unchanged labelled material. Generally, labelled cinnamic acids were recovered in pure form from the reaction mixture, with a loss of 6‐8%. Likewise, unchanged15NH3was reisolated as15NH4Cl after steam distillation with overall losses of less than 4%. Labelled cinnamic acids were prepared by Knoevenagel condensations between appropriately labelled benzaldehydes and malonic acids. [2‐2H]Benzaldehyde was obtained from 2‐bromotoluene by decomposition of the corresponding Grignard reagent with2H2O and subsequent oxidation. Since simple molecules, most of them commercially available in labelled form or otherwise easily accessible, may serve as starting material, and due to its defined stereochemistry, the reaction catalyzed by PAL opens a short and attractive route to speci

ISSN:0362-4803    

DOI:10.1002/jlcr.2580241106

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe synthesis of the bromoprazosin, in which bromination and acylation of furoic acid were completed by means of very simple method was described. The reductive catalyzed debromination with tritium gas afforded the (3H)‐prazosin. Its specific activity and radiochemical purity were 22.6 Ci/mmol and 98% respectivel

ISSN:0362-4803    

DOI:10.1002/jlcr.2580241107

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractPreparation of carbon 14‐labelled “Spy Dust”, 5‐(4‐nitrophenyl)‐2,4‐[5‐14C]pentadienal is described. The facile synthesis of 4‐nitro[formyl‐14C]benzaldehyde from 1‐iodo‐4‐nitrobenzene by reaction with K14CN/CuCN, followed by reduction with diisobutylaluminum hydride provided this key intermediate in 50% yield. Subsequent treatment with the resonance‐stabilized ylide, formylmethylenetriphenylphosphorane,

ISSN:0362-4803    

DOI:10.1002/jlcr.2580241108

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractA new antihypertensive agent, GYKI‐12743, has been labelled with carbon‐14 via a six‐step synthesis. The label was introduced by chain elongation of an appropriate precursor using potassium [14C]cyanide as radioactive starting material. A satisfactory overall yield, 44.7 %, relative to KCN was ach

ISSN:0362-4803    

DOI:10.1002/jlcr.2580241109

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe syntheses of two analogues of low‐density lipoprotein (LDL) labelled with123I or131I was optimized for radiopharmaceutical application. Rabbit LDL was employed due to its usefulness in pre‐clinical experimentation, although the parameters which were optimized also pertain to human LDL. LDL was iodinated directly with exchange‐labelled [123I]ICI to produce injectable [123I]LDL in 40% radiochemical yield within 30 min. A derivatized version of LDL, [123I]TC‐LDL, was produced in about 30% radiochemical yield within 75 min by radioiodination of tyramine‐cellobiose (TC) viain situoxidation of123I−followed by cross‐linking to LDL using cyanuric chloride. Quality control tests indicated that both radioiodinated LDL and TC‐LDL were very similar in character to the nati

ISSN:0362-4803    

DOI:10.1002/jlcr.2580241110

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractTwo syntheses of radiolabelled spiro‐piperidyl‐rifamycins are described.1. A five steps synthesis (Scheme 1) was performed to give 4‐deoxo‐3,4‐[2‐spiro‐(N‐[14C]methyl‐4‐piperidyl)]‐(1H)‐imidazo‐(2,5‐dihydro)‐rifamycin S ([14C]LM 118), in an overall radiochemical yield of ∼ 20%, 98% radiochemically pure and with a specific activity of 440 MBq/mmol (11.9 mCi/mmol) starting from [14C]methyl iodide1.2. A three steps synthesis (Scheme 2) was performed to give 4‐deoxo‐3,4‐[2‐spiro‐(N‐2‐methyl[1‐14C]propane‐4‐piperidyl)]‐(1H)‐imidazo‐(2,5‐dihydro)‐rifamycin S ([14C] rifabutin) in an overall radiochemical yield of ∼38%, 97% radiochemically pure with a specific activity of 1.27 GBq/mmol (34.32 mCi/mmol). 1‐(2‐Methyl[1‐14C]propan

ISSN:0362-4803    

DOI:10.1002/jlcr.2580241111

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

Abstract2‐Diethylaminoethyl phenylacetate was labelled by14C in two positions:‐ on the carboxylic group by means of14C‐phenylacetic acid.‐ on the aminoethanol part using14C ethanolamine as intermediate.Biodistribution studies were performed in rats for the two labellings after i.v. administration of the c

ISSN:0362-4803    

DOI:10.1002/jlcr.2580241112

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY