摘要:

AbstractL‐dihydroxyphenylalanine‐2H3, L‐tyrosine‐2H2, dopamine‐2H3, 3‐methoxytyramine‐2H3, homovanillic acid‐2H2, homovanillic acid‐2H5and vanillylmandelic acid2H2were prepared by hydrogen‐deuterium exchange under acidic or basic conditions. 4‐hydroxy‐3‐methoxy phenylethyleneglycol‐2H3was prepared from vanillylmandelic acid‐2H by reduction with LiA12H4. The isotopic yield for L‐dihydroxyphenylalanine was 90% and for the other compounds>99%. These labelled compounds could be used as internal standards in the mass fragmentographic analysis of the protium species in tissues and body fluids as well

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100202

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractAlpha‐methyldopa hydrochloride, specifically labelled with13C in the benzylic position, was prepared for use in biotransformation studies. Carbonation of the lithio derivative of 3,4‐dibenzyloxybenzene with13CO2(64 atom percent) was followed by LiA1H4reduction of the resulting benzoic acid. Oxidation with CrO3provided the benzaldehyde which was condensed with nitroethane to form the phenylnitropropene, Reduction of this phenylnitropropene with Fe/HOAc gave the corresponding phenyl‐2‐propanone which was converted to its hydantoin derivative. Base hydrolysis of the hydantoin followed by debenzylation in concentrated hydrochloric acid gave the desired alpha‐methyldopa hydrochloride in 16% over

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100203

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractThe preparation of lysergic acid [14C1]‐diethylamide is described. [14C1]‐Diethylamine was synthesised in three steps; sodium [14C1]‐acetate was treated with thionyl chloride giving [14C1]‐acetyl chloride which was reacted with ethylamine to give N‐ethyl‐[14C1]‐acetamide. Reduction of this amide with lithium aluminium hydride gave [14C1]‐diethylamine which on treatment with a lysergic acid‐imidazole complex gave the

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100204

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

Abstract2‐(2‐Pyridine)‐1‐(3‐chlorophenyl)‐2‐phenyl‐1‐methylethanol (I), containing tritium uniformly distributed in the 2‐phenyl ring, was synthesized in two steps with tritiated benzene as the labelled starting material.An improved procedure was employed for the coupling of m‐chloroacetophenone and 2‐benzylpyridine. The higher melting of two enantiomeric pairs, known for its hypocholesteremic activity in rats, was isolated and found to have a chemical purity of>95% and a specific act

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100205

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractThe synthesis and purification of suitable radioactive tracers for organic solid state self diffusion experiments is described. Particular attention is paid to the isotope effect which requires two tracers containing different radioactive isotopes, and with as large a mass difference as possible. The latter is accomplished by incorporating a stable isotope in one of the tracers. Active preparations of adamantane, dl‐camphene, bromopentamethyl‐ethane, and hexamethylethane are repor

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100206

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractLes auteurs décrivent les améliorations qu'ils ont apportées aux proaédés déjà connus de synthèse de la DL‐lysine, marquée à 1′15N en α ou en ϵ La bis N α N ϵ‐chloracétyl lysine, nécessaire pour réaliser le dédoublement de la DL lysine sous l′action de l'acyclase est préparée avec un bon rendement à l'aide du chlo

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100207

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

Abstract18Oxygen labeled 17α‐hydroperoxyprogesterone has been synthesized via a 3‐step reaction sequence in an all‐glass, high vacuum transfer system. The hydroperoxidation reaction was found to proceed smoothly only, when an adequate oxygen pressure in the reaction vessel is maintained. Comparisons are made between the mass spectral fragmentations of the ordinary16O, and the isotopically labeled180–17α‐hydroperoxyprogesterones. Their NMR‐spectra display a splitting of the 18‐, and 31‐methyl signals, probably due to the coexistence of two finite conformations of the

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100208

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractA procedure for the site‐specific labeling of indole derivatives has been developed. The procedure utilizes the blocking and activating properties of thep‐toluenesulfonyl group which allows for the facile metalation at the 2‐position of indole withn‐butyllithium and incorporation of deuterium upon reaction with2H2O. Removal of thep‐toluenesulfonyl group is achieved by treatment with sodium in liquid ammonia and occurs with retention of

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100209

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractThe selective tritiation of the methylene carbon atom of the carcinogens, N‐fluoren‐3‐yl‐and N‐fluoren‐1‐ylacetohydroxamic acid, has been investigated. The synthesis of N‐[9‐3H]fluoren‐3‐ylacetohhydroxamic acid involves hydrogenolysis of 3‐aminofluoren‐9‐one to [9‐3]fluoren‐3‐amine with LiAl3H4‐A1C1‐. The tritiated amine is oxidized to 3‐nitro‐[9‐3H]fluorene with m‐chloroperoxybenzoic and the labeled nitro compound is partially hydrogenated to the3H‐hydroxamic acid with 10% Pd–C catalyst in presence of acetic anhydride and triethylamine or dimethylaniline. N‐[9‐3H]fluoren‐1‐ylacetohydroxamic acid may be obtained from 1‐aminofluoren‐9‐one by the same procedure. However, N‐[9‐3H]fluoren‐2‐ylacetohydroxamic acid cannot be prepared in this way because reduction of 2‐aminofluoren‐9‐

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100210

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractL'acide NN dichloro‐2, ethyl p amino phényl‐4, butyrique est marqué par14C en trois positions différentes:sur le carbone portant la fonction carboxylique à partir de K14CN.uniformément sur les quatre carbones du groupement dichloroéthyl à partir d'oxyde d'éthylène radioactif.sur le carbone placé en α de la fonction carboxylique à

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100211

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY