摘要:

AbstractThe potent antimetabolite, 2‐fluoro‐L‐histidine, has been synthesized from 2‐fluoroimidazole with nonexchangeable3H labeling in the side chain. 2‐Fluoro‐4‐iodoimidazole was N‐tritylated, was subjected to metal‐halogen exchange with n‐butyllithium, and the carbanion formylated with DMF. The imidazole‐4‐aldehyde was condensed with hippuric acid, the azlactone was solvolyzed with methanol, and the trityl group was removed by selective reduction with PtS2. The resultinq 2‐fluoro‐α‐benzamidoacrylic ester was reduced with tritium gas and the blocking groups were removed successively with base and with acylase I to produce the L‐enantiomer

ISSN:0362-4803    

DOI:10.1002/jlcr.2580230102

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe title compound was synthesized with a specific activity of 30 Ci mmol−1and with radiochemical purity of 96% by iodination of the sulphoxide followed by catalytic tritiation of an isolated fraction. Iodination and reduction studies on model peptides are reported. Alternative philosophies for preparing tritiated peptides are critically discusse

ISSN:0362-4803    

DOI:10.1002/jlcr.2580230103

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe syntheses of [benzimidazole‐2‐14C]omeprazole, [benzimidazole‐2‐13C]omeprazole, [35S]omeprazole and [2‐pyridyl‐14C‐methyl]‐omeprazole are described. The first three compounds were prepared from the approprlate isotopically labelled carbon disulphide. The key step in the synthesis of [2‐pyridyl‐14C‐methyl]omeprazole is nucleophilic alkylation of a 1‐ethoxypyridinium salt using [14C]methyl magnesium idodide. This is the first time that a reaction of this type has been used to prepare a 2‐[m

ISSN:0362-4803    

DOI:10.1002/jlcr.2580230104

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractDezaguanine mesylate (CI‐908 mesylate, 3‐deazaguanine mesylate, 6‐amino‐1,5‐dihydro‐4H‐imidazo[4,5‐c]pyridin‐4‐one methanesulfonate,7), a new antitumor agent, was labeled in‐the 2‐position by use of a new synthesis to 3‐deazaguanine. Thus, methyl 4‐(hydroxymethyl)‐1‐(triphenylmethyl‐1H‐imidazole‐5‐carboxylate (10) was converted with thionyl chloride to the corresponding chloromethyl‐derivative11, which was treated with [14C]‐potassium cyanide to afford the labeled penultimate intermediate, methyl 5‐(cyanomethyl)‐1H‐imidazole‐4‐carboxylate (12). Ring closure of12with methanolic ammonia and subsequent salt f

ISSN:0362-4803    

DOI:10.1002/jlcr.2580230105

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe synthesis of two benzamide derivatives labelled with carbon‐14 at the carboxamide position is described. The radioactive label was introduced by the reaction of 1,3‐dimethoxy‐2‐lithiobenzene with [14C]carbon dioxide to furnish 2,6‐dimethoxy[carboxy‐14C]benzoic acid (2). Halogenation of2with dioxane dibromide or sulphuryl chloride followed by reaction with thionyl chloride led to the corresponding labelled acid chlorides. These were reacted with (S)‐2‐(aminomethyl)‐1‐ethylpyrrolidine (5) and converted into [14C]remoxipride (6) and [14C]racloprid

ISSN:0362-4803    

DOI:10.1002/jlcr.2580230106

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractVeralipride was labelled with trideuteromethyl groups first in the o‐methoxy and later in both o‐and m‐methoxy positions respective to the benzamide functions. Hydroxylated benzaldehydes were the starting materials and (CD3)2SO4the labelling substance. A known synthesis was followed for veralipride‐d3. This synthesis was extensively modified in the final steps for veralipride‐d6by introducing an ester exchange reaction which increased the over

ISSN:0362-4803    

DOI:10.1002/jlcr.2580230107

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe preparation of75Se‐ebselen (75Se‐PZ 51) in a high radiochemical yield (∼40 %) and with a specific activity of 240 mCi/mM (8.9 GBq/mM) is described. It entails a very simple, fast and one‐pot procedure starting from elemental75Se‐selenium.75Se‐diselenosalicylic acid4is initially prepared as the key intermediate which is transformed into a corresponding dichloride5‐before reacting with aniline to yield the desired75Se‐ebselen.Identity and purity of the labelled compound were controlled by comparison in TLC, HPLC and MS with an authent

ISSN:0362-4803    

DOI:10.1002/jlcr.2580230108

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe synthesis of the title compound is described from heptadeuterated isopropyl alcohol in six steps. Overall yield obtained was 6%.

ISSN:0362-4803    

DOI:10.1002/jlcr.2580230109

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractA method for transformation of readily available beta‐vinyl 99% carbon‐13 enriched derivatives of protoporphyrin‐IX dimethyl ester (3‐5) into the less accessible alpha‐vinyl labelled isomers (6‐8) is described. The procedure involves thallium(III) promoted vinyl carbon rearrangement, and proceeds through 2,2‐dimethoxyethyl (e.g.10), formylmethyl (e.g.11), 2‐hydroxyethyl (e.g.12) and 2‐chloroethyl (e.g.13) porphyrins; the rearranged vinyl groups are regenerated from 2‐chloroethyl in the last step by treatment with base. No evidence of vinyl carbon scrambling in the sequence is observed, and spectroscopie data of the

ISSN:0362-4803    

DOI:10.1002/jlcr.2580230110

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY

摘要:

AbstractThe radioiodination of 4‐trimethylsilylbenzyl bromide in acetic acid with no carrier added I‐125 and I‐123 iodide ion and N‐chlorosuccinimide (NCS) is a rapid, high yielding process which produces high specific activity 4‐[I‐125 or I‐123]iodobenzyl bromide. This radiolabelled alkylating agent has been efficiently reacted with N,N‐dimethylaniline and triphenylphosphine to generate radiolabelled quaternary ammonium and phosphonium salts, and should be useful for labelling other biologically important molecules which possess suitable nucleophilic fu

ISSN:0362-4803    

DOI:10.1002/jlcr.2580230111

出版商:John Wiley&Sons, Ltd.    

年代:1986

数据来源: WILEY