摘要:

Abstract[5′‐3H]‐5‐Chloro‐2′,3′‐diodeoxy‐3′‐fluorouridine (1; R = [3H]) was prepared at a specific activity of 10.2 Ci/mmol suitable for development of a radioimmunoassay procedure. The synthetic sequence employed controlled oxidation of unlabelled1to the 5′‐aldehyde (2), isolation as the imidazolidine adduct (3), regeneration of the free aldehyde, reduction with [3H]NaBH4, and purification by preparative TLC. The radio

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360802

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractF‐18 labeled SR46349B, a highly potent and selective 5‐HT2receptor antagonist, was synthesized as a potential radioligand for PET studies of brain 5‐HT2receptors. Nucleophilic aromatic substitution oftrans‐1‐(2‐nitrophenyl)‐3‐(4‐methoxymethoxyphenyl)‐2‐propenone (10) with NCA [18F]fluoride in the presence of potassium carbonate and kryptofix‐222, followed by HCl hydrolysis, gave F‐18 labeled12, which was purified by a novel combination of C‐18 Sep‐Pak and silica column chromatography. Subsequent condensation of [18F]ketone12with Me2NCH2CH2ONH2gave a mixture of [18F]SR46349B and its geometric isomer, which was separated by high performance liquid chromatography. The three step hot synthesis of [18F]SR46349B required 170 min. and gave a specific activity of 1140 Ci/mmol, 5% radiochemical yield (EOB)

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360803

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

Abstract[α‐11C]Benzoyl chloride was synthesized and purified by normal phase HPLC. [11C]MK‐996 ([11C]N‐[[4′[(2‐ethyl‐5,7‐dimethyl‐3H‐imidazo [4,5‐b]pyridin‐3‐yl)methyl][1,1′‐biphenyl]‐2‐yl]sulfonyl]‐benzamide), a potent and selective ligand for the AT1receptor, was prepared byN‐benzoylation of L‐159,221 with [α‐11C]benzoyl chloride in tetrahydrofuran using lithium bis(trimethylsilyl)amide as a base. The radiotracer was purified by semi‐preparative reverse‐phase HPLC. The average specific activity was 1162 mCi/μmol calculated at end‐of‐synthesis (EOS). The average time

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360804

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractA new route to semisynthetic Taxotère®,1. is described using the mixed anhydride obtained from 2,4,6‐trichlorobenzoyl chloride and [3‐14C]‐cinnamic acid6, for the esterification of 7,10‐O‐diTroc‐10‐deacetylbaccatin III,4. Hydroxyamination on the unsatured C‐2′,3′,deprotection of the C‐7,10‐Troc groups of the ester7gave Taxotère®1. [3′‐14C]Taxotère®9(specific activity: 50 mCi/mmol) was obtained from [3

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360805

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe condensation of ethyl acetoacetate‐13C4and ethyl bromoacetate‐13C2afforded, in seven steps, (1,2,3,4,5‐13C5) 5‐(diethylphosphono)‐2‐pentanone ethylene ketal9. The reaction of this labelled compound with 7‐[[(1,1‐dimethylethyl)‐dimethylsilyl]oxy]‐1,6,6a,7,8,9,9a, 9b‐octahydro‐6a‐methyl‐[6aS‐(6aa,7a,9aβ,9ba)] cyclopental[f][1]benzopyran‐3 (2H)‐one13gave the benzindenone14which was converted to (1,2,3,4,10,19‐13C6)testosterone17then, into (1,2,3,4,10‐13C5) 19‐nortestos

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360806

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

Abstract1‐[13CD3]‐9‐cis‐Retinoic acid was prepared in 8 steps from 2,6‐dimethylcyclohexanone. Alkylation of 2,6‐dimethylcyclohexanone under LiHMDS/MnBr2/13CD3I gave the corresponding labeled 2‐[13CD3]‐2,2,6‐trimethylcyclohexanone4in good yield. Further functionalization of4to 6‐[13CD3]‐β‐cyclocitral6proceeded through a Shapiro reaction. Aldehyde6was condensed with ethyl 3,3‐dimethylacrylate to afford the corresponding bicyclic pyranone7. Reduction of7to lactol8, followed by acid‐catalyzed ring opening gave the 9‐cis‐aldehyde9. Wittig‐Horner olefination and saponification afforded the title compound in good overall yiel

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360807

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractWe describe herein, a novel synthesis of the previously unreported compound, 4,6‐dibromo‐2‐pyridone(3)and its use in the preparation of [3H]‐RS‐91309, a potassium channel modulator. This key intermediate,(3), was reduced with carrier free tritium gas to furnish [4,6‐3H]‐2‐pyridone(9)having a specific activity of 50 Ci/mmole. Condensation of(9)with epoxide(10), followed by elaboration of the resulting chromene methyl group of(12)gave [3H]‐RS‐91309(14)whose specific activity was also 50 Ci/mmole. This chemistry, as well as the solution of several microscale related stoichiometry pr

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360808

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

Abstract3‐[Methyl‐13C]xanthine, 7‐[Methyl‐13C]xanthe, 1,3‐[Dimethyl‐13C2]xanthine (theophylline‐1,3‐[13CH3]2), 1,7‐[Dimethyl‐13C2]xanthine (paraxanthine‐1,7‐[13CH3]2), and 3,7‐[Dimethyl‐13C2]xanthine (theobromine‐3,7‐[13CH3]2) were synthesized by nucleophilic substitution reaction (SN2) from xanthine (X) and iodomethane‐[13C]. The 3‐isobutylparaxanthine‐7‐[13CH3] was prepared from 3‐isobutyl‐1‐methylxanthine (IBMX). The compounds were purified by reverse phase semipreparative liquid chromatography and their ch

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360809

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe title compound was prepared by the LiAlT4reduction of 5‐fluoro‐3‐[3‐[4‐(5‐methoxy‐4‐pyrimidinyl)‐1‐piperazinyl]‐3‐oxopropyl]‐1H‐indole. The radiochemical purity of the product was 98.9% and the specific activity was calculated as 53.0 Ci/mmol from HPLC analyses and 55.6 Ci/m

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360810

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractEmodin, a precursor of chrysophanol in the biosynthesis of cynodontin byPyrenochaeta terrestris, has been tritiated with a high specific radioactivity (12.5 Ci/mmol) by hydrogenolysis of bromomethyl emodin.

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360811

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY