摘要:

Abstract7‐Chloro‐1,3‐dihydro‐5‐(2‐fluorophenyl)‐1‐methyl‐2H‐1,4‐benzodiazepin‐2‐one (Fludiazepam) (I), an anti‐anxiety agent, was labelled with carbon‐14 at C‐5 position for metabolic studies. The reaction sequence for the synthesis is shown in Fig. 2. o‐Fluorobenzoic‐14C acid (IV) was prepared in 65% yield by carbonation of o‐fluorophenyllithium with carbon‐14C dioxide. The acid (IV) was condensed with N‐(4‐chlorophenyl)‐N‐ methylethylenediamine, followed by Bischler‐Napieralski cyclization of the resulting amide with phosphorus pentoxide and phosphorus oxychloride to afford 7‐chloro‐2,3‐dihydro‐5‐(2‐fluorophenyl)‐1‐methyl‐1H‐1,4‐benzodiazepine‐5‐14C (VII) in good yield. Oxidation of VII by N‐bromosuccinimide in aqueous solution of sodium bicarbonate gave

ISSN:0362-4803    

DOI:10.1002/jlcr.2580130401

出版商:John Wiley&Sons, Ltd.    

年代:1977

数据来源: WILEY

摘要:

AbstractNornicotine‐2,4,5,6‐d4and its N′‐nitroso derivative were synthesized from pyridine‐d5. Initially, pyridine‐d5was brominated in fuming D2SO4to give 3‐bromopyridine‐d4. Treatment of this material with n‐butyllithium and dry ice followed by acidification gave nicotinic acid‐2,4,5,6‐d4. Conversion of this substance to the acid chloride hydrochloride (via thionyl chloride) followed by treatment with absolute ethanol gave ethyl nicotinate‐2,4,5,6‐d4. The ester was condensed with N‐trimethylsilyl‐2‐pyrrolidinone in the presence of n‐butyllithium and diisopropylamine to give, after hydrolysis and decarboxylation, myosmine‐2,4,5,6‐d4. Reduction of this material with sodium borohydride gave nornicotine‐2,4,5,6‐d4. Conversion to the N′nitroso derivative

ISSN:0362-4803    

DOI:10.1002/jlcr.2580130402

出版商:John Wiley&Sons, Ltd.    

年代:1977

数据来源: WILEY

摘要:

AbstractBenzene oxide ‐[U‐14C] was prepared from benzene ‐(U‐14C) by modifications of methods described for the inactive compound.Benzene oxide‐[3.6–3H] was prepared by decomposition of 3.6‐bis‐trimethylsilyl‐1,4‐cyclohexadiene with tritiated water. bromination of the 1,4‐cyclohexadiene‐[3,6‐3H] so obtained. epoxidation and dehydrobromination.With the latter method benzene oxide‐[3,6–3H] can be prepared at a much lower cost and higher specific activi

ISSN:0362-4803    

DOI:10.1002/jlcr.2580130403

出版商:John Wiley&Sons, Ltd.    

年代:1977

数据来源: WILEY

摘要:

AbstractThe title compound was prepared from 4‐ethylthio‐1‐naphalenesulfonyl chloride in a two‐step synthesis with an overall yield of 56%. An alternative one‐step synthesis from 4‐ethylsulfonyl‐1‐naphthalenesulfonyl chloride was found to be unsuitable for ni

ISSN:0362-4803    

DOI:10.1002/jlcr.2580130404

出版商:John Wiley&Sons, Ltd.    

年代:1977

数据来源: WILEY

摘要:

AbstractA convenient synthesis of the14C‐labelled chloromethyl ketone analog of leucine is reported. Modification of previously published conditions allowed for the facile synthesis of: 2–14C‐3‐amino‐1‐chloro‐5‐methylhexan‐2‐one hydrochloride in four steps from 1‐14C‐DL‐leucine in 85.7% yield. This represented a four‐fold improvement over yields reported previously

ISSN:0362-4803    

DOI:10.1002/jlcr.2580130405

出版商:John Wiley&Sons, Ltd.    

年代:1977

数据来源: WILEY

摘要:

AbstractLabeled ruthenocenes were prepared by heating substituted ferrocenes with103RuCl3involving (Π‐ligand)‐(Π‐ligand) exchange. Coproportionation and disproportionation of a mixture of a radioactive metallocene compound and an inactive one in the presence of catalytic amounts of FeCl3or RuCl3provided a variety of labeled metallocenes in a simple one step pr

ISSN:0362-4803    

DOI:10.1002/jlcr.2580130406

出版商:John Wiley&Sons, Ltd.    

年代:1977

数据来源: WILEY

摘要:

AbstractThe synthesis of 2‐ethyl‐2‐phenyl‐d5‐glutarimide (glutethimide‐d5) and its mass fragmentometry i

ISSN:0362-4803    

DOI:10.1002/jlcr.2580130407

出版商:John Wiley&Sons, Ltd.    

年代:1977

数据来源: WILEY

摘要:

AbstractThe carbon of the N‐ethyl group of the side‐chain of atabrine (I) has been labelled with carbon‐14 as part of a metabolic study of this compound. The overall radiochemical yield was 38% based on ethyl‐1–1

ISSN:0362-4803    

DOI:10.1002/jlcr.2580130408

出版商:John Wiley&Sons, Ltd.    

年代:1977

数据来源: WILEY

摘要:

AbstractFluorine‐18 produced via the reaction chain6Li(n,α)t,16O(t,n)18F by reactor irradiation of Li2CO3was directly recovered in carrier‐free form with a 90% yield by repeated extractions with water. A simple apparatus was used for simultaneous extraction and fast loading of an exchange resin with 18F. Dowex 1×4 in the acetate form was found to be best suited for a gas phase 18F‐for‐Br exchange in α‐bromofatty acid esters. The 18F‐loaded exchange resin was brought into a gas chromatographic column followed by an analytical column for the separation of the 18F‐labelled product from the unchanged bromine compound. The dynamic technique combines synthesis and purification and allows a fast and carrier‐free production of 18F‐α‐fluorofatty acid esters with boiling points up to about 300 °C. α‐fluoroacetic acid ethyl ester and α‐fluorovaleric acid methyl ester have been labelled carrier‐free with yields of 64% (at 170 °C) and 39% (at 190 °C), respectively. Kinetic studies on the yield determining

ISSN:0362-4803    

DOI:10.1002/jlcr.2580130409

出版商:John Wiley&Sons, Ltd.    

年代:1977

数据来源: WILEY

ISSN:0362-4803    

DOI:10.1002/jlcr.2580130410

出版商:John Wiley&Sons, Ltd.    

年代:1977

数据来源: WILEY