摘要:

AbstractThe incorporation of tritium gas into dioxan, tetrahydrofuran, ethyl acetate, dimethylformamide, dimethylacetamide, dimethylsulfoxide and acetic acid anhydride was studied in the presence of heterogeneous catalysts PdO (Adams), PtO2(Adams), Pd/BaSO4(10%). For the solvents and catalysts investigated the following dependencies were observed:1Wllzbach reaction of the solvents takes only a negligible part in the total incorporation into the solvents.2The traces of exchanging impurities in solvents caused much higher incorporation.3In the case of non exchanging solvents, practically all the radioactivity incorporated is bound on tritium water.

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100402

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractThe preparation of 9α, 11ζ‐tritiated estrone‐3‐methyl ether with high specific activity is described. The following syntheses gave 17α‐CH2X‐derivatives of estradiol (X = CN and SCN) with high specific activity and radiochemical purity higher than 98%. Radiolysis and storage conditions

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100403

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractA synthesis of [24‐3H] (24S)‐cholest‐5‐ene‐3β, 24‐diol (cerebrosterol) in 12.1% radiochemical yield and of its 24‐epimer has been achieved by sodium borotritide reduction of 3β‐hydroxycholest‐5‐en‐24‐one derived from 3β‐hydroxychol‐5‐enic acid by an improved procedure. The epimeric 3β, 24 diols were separated as the dibenzoate esters, for which circular dichroism data are presented in support of the

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100404

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractA convenient synthesis of 5α‐[20β‐2H]pregnane‐3α,20α‐diol and 5α‐[20β‐2H]pregnane‐3β,20α‐diol from 3β‐hydroxy‐5α‐pregn‐16‐en‐20‐one is described. The reaction products are characterized by combin

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100405

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractAccurate knowledge of the stability of (3H)‐uridine, (3H)‐thymidine, and their triphosphates is important for their use as tracers in biological systems. Data for the stability of these compounds at different storage temperatures and in the presence of a stabiliser, ethanol, are presented. The effects observed are discussed in terms of current theories on radiation self‐decompos

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100406

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractIn a new approach to the specific labelling of organic compounds with tritium use is made of isotope exchange with tritium of certain specific hydrogen atoms in organic molecules when stirred with tritium gas in solution at room temperature in the presence of a metal hydrogen transfer catalyst. Specifically labelled tritiated compounds of high specific activity and radio‐chemical purity are obtained.The method can be used for labelling a wide variety of organic compounds including purines, purine nucleosides and nucleotides, aromatic amines and amino acids, carbohydrates and steroids. Numerous examples are cited and possible mechanisms discusse

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100407

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

Abstract1,4‐Dihydro‐1‐methoxy‐6,7‐methylenedioxy‐4‐oxoquinoline‐3‐carboxylic acid (I) (AB‐206), a new synthetic antimicrobial agent, was labelled with carbon‐14 at C‐3 position of the quinolinone ring for metabolic studies. The synthesis was achieved according to the reaction schemes shown in Fig. 1 and 4; which involved a newly devised key‐reaction, the condensation of diethyl malonate‐2‐14C with ethyl orthoformate and 3,4‐methylene‐dioxyaniline in the presence of anhydrous zinc chloride as a catalyst to ethyl α‐carbethoxy‐β‐(3,4‐methylenedioxyanilino) acrylate‐2‐14C (III). The overall radiochemical yield

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100408

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractO,S‐Dimethyl phosphoroamidothioate has been synthesized with32P and with14C in the methoxy and the S‐methyl group. Phosphorus trichloride was reacted with sulfur giving phosphorrus thiochloride. The latter was reacted with methanol in the presence of acridine and calcium oxide yielding O‐methyl phosphorodichloridothioate. Isomerization at 100°C gave S‐methyl phosphorodichloridothioate. Finally, treatment with methanol and ammonia gave O,S‐dimethyl phosphoroamidothioate.32P‐labelled phosphorus trichloride and14C‐methanol were appropriately introduced to yield the desired compound.The intermediates and final product were characterized by NMR, mass spectra and TLC. Products were purified by solvent partition (S‐methyl labelled) and anion exchange chromatography (32P‐labelled). Radiochemical purity was determined by TLC. Liquid Scintillation counting was used to determine specific activities. The32P‐labelled compound had a specific activity of 163 μCi/mM while the14C‐methoxy and S‐methyl compounds had specific activities of 86 a

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100409

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractThe synthesis of 3‐[ 2′,4′,5′‐triethoxybenzoyl‐(carbonyl‐14C)]‐propionic acid (VII) is described. Chloroacetonitrile‐14C (IV) was prepared from chloroacetic‐1‐14C acid (I) according to the well‐known procedure. IV was reacted with 1,2,4‐triethoxybenzene in the presence of ZnCl2and HCl, and the resulting ketoimine hydrochloride was hydrolyzed to 2′,4′,5′‐triethoxyphenacyl‐(carbonyl‐14C) chloride (V) in 66.5% yield. VII was obtained in 66% from ethyl [2′,4′,5′‐triethoxyphenacyl‐(carbonyl‐14C)] malonate (VI) which had been prepared in 57% from V by an application of malonic ester synthesis. The ov

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100410

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractLa synthèse améliorée de la progestérone14C‐4 est décrite. La purification de la progestérone14C‐4 par chromatographie sur colonne de silicate de Mg et CCM préparative a permis l'isolement de deux sous‐produits: isoprogestérone14C‐4 et trioxo‐3,5,20‐seco A‐4,5 pregnane14C‐4, identifiés par spectrométrie RMN et de masse. Rendement radioactif global: 40% par rapport à14CO3Ba, acti

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100411

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY