摘要:

Abstract2‐Propyl‐8‐oxo‐1‐[(2′‐(1H‐tetrazole‐5‐yl) biphenyl‐4‐yl)methyl]‐4, 5, 6, 7‐tetrahydrocyclohept imidazole (KT3‐671), which has been found to be a potent and selective angiotesin II receptor antagonist, was synthesized in14C‐labelled form by using potassium[14C]‐cyanide. [14C](KT3‐671) 9 with a specific activity of 1.74GBq/mmol was prepared in four steps in 29.8% overall radio‐chemi

ISSN:0362-4803    

DOI:10.1002/jlcr.2580361002

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractWe describe a method for n.c.a. radioiodination of pyrrolidino tamoxifen (Idoxifene) based on the electrophilic destannylation of tributylstannyl pyrrolidino tamoxifen. The methods of separation using preparative tlc and HPLC give>95% radiochemical purity and>70% recovery.

ISSN:0362-4803    

DOI:10.1002/jlcr.2580361003

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe deuterium labeled form of mosapride citrate, a potential gastroprokinetic agent, was preparedviareduction of ethyl 4‐(4‐fluorobenzyl)‐2‐morpholinecarboxylate (4) with lithium borode

ISSN:0362-4803    

DOI:10.1002/jlcr.2580361004

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe compound Ro 19‐6327, N‐(2‐aminoethyl)‐5‐chloropyridine‐2‐carboxamide, is known to inhibit reversibly and site specifically the enzyme monoamine oxidase B (MAO‐B). The123I‐labelled iodo‐analogue N‐(2‐aminoethyl)‐5‐iodopyridine‐2‐carboxamide (Ro 43‐0463) was investigated successfully in human volunteers by means of SPET (Single Photon Emission Tomography). We developed therefore the synthesis and radiolabelling of the corresponding fluoro‐analogue N‐(2‐aminoethyl)‐5‐fluoropyridine‐2‐carboxamide with18F in order to carry out PET (Positron Emission Tomography) investigations of MAO‐B related neuropsychiatric diseases. For this purpose two synthetic approaches leading to the electrophilic and the nucleophilic methods of18F radiolabelling were undertaken. The nucleophilic approach appeared to be superior when factors such as precursor synthesis, beam time, specific activity and r

ISSN:0362-4803    

DOI:10.1002/jlcr.2580361005

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractWe have reinvestigated the synthesis of [15N2]hydroxymethyl imidazole from dihydroxyacetone, formaldehyde, and labelled ammonia in an attempt to optimize the yield from the isotope. Conversion of the hydroxymethyl imidazole to histidine was accomplished in good yield without the need for picric acid as an ion pairing agent.

ISSN:0362-4803    

DOI:10.1002/jlcr.2580361006

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractA method is described for synthesis of riboflavin selectively labeled in the hydrogens at the 5′‐hydroxymethyl position. In this method, a vitamin B2‐aldehyde‐forming enzyme fromSchizophyllum communeis used to specifically and completely oxidize the 5′‐hydroxymethyl of riboflavin to the 5′‐aldehyde. This reaction is monitored spectrophotometrically by the reduction of 2,6‐dichlorophenolindophenol at 600 nm. Appearance of aldehyde product was directly quantitated by reverse‐phase high‐performance liquid chromatography. Product is extracted from the incubation mixture by phenol after saturation with (NH4)2SO4and then further purified by benzyl alcohol extraction. The 5′‐aldehyde is reduced with appropriately labeled sodium borohydride to yield the vitamin specifically labeled in t

ISSN:0362-4803    

DOI:10.1002/jlcr.2580361007

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe synthesis of racemic [2‐{(4‐Chlorophenyl) (4‐iodophenyl)} methoxyethyl]‐1‐piperidine‐3‐carboxylic acid, (CIPCA) and its radioiodinated analog [125ßI]CIPCA is described. CIPCA was synthesized from 4‐iodobenzoyl chloride in five steps in 16% overall yield. Ammonium sulfate catalyzed solid‐state isotopic exchange of CIPCA with Na125I provided [125I]CIPCA in 34% isolated radiochemical yield at a specific activity of 118 Ci/mmol. [125ICIPCA] demonstrated moderate brain extraction and goodin vivoradiostability in preliminary biodistribution studies conducted in CD‐1 mice. [125I]CIPCA is a potentially useful radiotracer for study of th

ISSN:0362-4803    

DOI:10.1002/jlcr.2580361008

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe antihistamine acrivastine and a metabolite dihydroacrivastine were prepared as their [2H7]‐congeners from [2H8]‐tolualdehyde for use as internal standards in gas chromatography/mass spectroscopy of biological samp

ISSN:0362-4803    

DOI:10.1002/jlcr.2580361009

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractFolic acid plays a key role in nucleic acid biosynthesis, essential for normal cell proliferation and function. Localized folate deficiencies may be related to changes in cytology associated with cancer development; analogs of folic acid, such as methotrexate, are potent chemotherapeutic agents and are widely used either alone or in combination therapy for many types of cancer. In this report we describe the synthesis of a tetra‐deuterated folic acid from perdeuterated toluene. The primary intermediate, N‐(4‐amino [2,3,5,6‐2H4]benzoyl)‐L‐glutamic acid diethyl ester was coupled to N(2′)‐acetyl‐6‐formylpterin to create [2′,3′,5′,6′‐2H4]folic acid. A similar scheme can be used for the preparation of [1′,2′,3′,4′,5′,6′‐13C6]

ISSN:0362-4803    

DOI:10.1002/jlcr.2580361010

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractSyntheses of labelled versions of 5‐HT3receptor antagonists, Alosetron and Lurosetron, are described. [14C]Alosetron was prepared by routes utilizing either Fischer indolisation of an amidohydrazine or palladium‐mediated cyclisation of an aryl enaminone as key steps.2H and13C versions of Alosetron were prepared from suitably labelled imidazoles. Lurosetron was labelled in either the methylene bridge carbon or carbonyl carbon, using14C‐labelled paraformaldehyde or phosgene, respect

ISSN:0362-4803    

DOI:10.1002/jlcr.2580361011

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY