摘要:

AbstractAs potential P.E.T. imaging agents for the benzodiazepine receptor, two fluorine‐ 18 labeled analogues of the β‐carbolines were preparedviaN‐ alkylation of the corresponding desbenzyl amine precursors with [18F]fluorobenzyl

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360302

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractTwo14C‐isotopomers of duloxetine HCl (S‐(+)‐N‐methyl‐3(1‐naphthal‐ enyloxy)‐3(2‐thiophene)propanamine hydrochloride), a potent mixed serotonin/norepinephrine uptake inhibitor have been prepared by an asymmetric synthesis. The palladium catalyzed cross‐coupling of 2‐thienoyl chloride (3c) (or its [carbonyl‐14C] isotopomer3d) with vinyl tri‐n‐butylstannane, followed by addition of HCl afforded the key pro‐chiral intermediate chloroketone (5a,b). Chiral reduction with borane in the presence of the appropriate oxazaborolidine catalyst (14aorb) provided theS‐chloroalcohol (7a) and its14C‐labeled counterpart7bor the analogousR‐chloroalcohol (6). Activation of7a,bby reaction with NaI/ acetone, followed by reaction of the corresponding iodoalcohol with methylamine yielded the penultimate aminoalcohols (8a,b). Formation of the alkoxide with NaH, followed by reaction with 1‐fluoronaphthalene yielded duloxetine or its14C‐labeled isotopomer9. Alternatively, reaction of6with 1‐naphthol‐[1‐14C] under Mitsunobu conditions afforded arylether10a,b, which was in turn activated by reaction with NaI/acetone. Subsequent reaction of10c,dwith methylamine followed by salt formation yielded duloxetine or its naphthale

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360303

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

Abstract(n‐Butoxy‐2′,2′,3′,3′,4′,4′,4′‐d7)acetic acid (1) and 2‐(n‐butoxy‐2′,2′,3′,3′,4′,4′,4′‐d7)ethanol (2) have been prepared in high yield fromn‐butanol‐2,2,3,3,4,4,4‐d7.n‐ Butoxy(13C2‐acetic) acid (3) and 1‐n‐butoxy‐2‐hydroxy(13C2‐ethane) (4) have also been synthesized using bromoacetic‐13C2acid as the source of labelled carbon. The main complication in the development of the process was partial conversion of butoxyacetic acid to butyl butoxyacetate d

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360304

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractPreparation of radiolabeled [125I]‐N,N′‐bis(2,3‐dihydroxypropyl)‐5‐(3‐hydroxy‐2‐oxo‐1‐piperidinyl)‐2,4,6‐ triiodo‐1,3‐benzenedicarboxamide, ([125I]‐3H2‐iopiperidol‐A), a nonionic radiographic contrast agent, was achieved by HAuCl4mediated exchange radioiodination. [125I]‐Iopiperidol‐A was isolated by reversed‐ phase HPLC in 83% radiochemical yield. The radiochemical purity of isolated [125I]‐3H2‐iopiperidol‐A was 98.7% and the specific activity was 6.6 mCi/μmol. The role of HAuCl4in facilitating exchange radioiodination of 3H2‐iopiperidol‐A, however, appears to be a complex process not l

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360305

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe synthesis of [1,1,3‐3H]‐2‐vinyl dihydrosphingosine‐1‐phosphate is described. The key step in this synthesis is the reduction of methyl 2‐trifluoro acetamido‐2‐vinyl nonadecanoate‐3‐one by means of3H‐calcium diborohydride. This compound was synthesized to determine whether 2‐vinyl dihydrosphingosine‐1‐phosphate inhibits the PLP‐dependent sphingosine‐1‐phosphate lyase irr

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360306

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractA method for labelling 6,7‐dichloro‐2,3‐dihydroxyquinoxaline (DCQX) in position 2 with carbon‐11 is presented. Diethyl [1‐11C]oxalate was synthesized in a two‐step, microwave‐assisted procedure from no‐carrier‐added [11C]cyanide and was reacted with 4,5‐dichloro‐1,2‐phenylenediamine in sulfuric acid at 150°C for 10 min. [2‐11C]DCQX, isolated by semi‐preparative HPLC, was>99% radiochemically pure with a specific activity ranging between 19 ‐ 26 TBq/mmol. The total time of synthesis was 45–55 min and the isolated, decay‐corrected yields were on the order of 10%, based on the trapped [11C]cyanide. A PET study of its biodistribution after intravenous injection in a male rat revealed that the extraction of [2−11C]DCQX across the

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360307

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe muscarinic cholinergic receptor antagonist dexetimide and its pharmacologically inactive enantiomer levetimide were labelled with the positron emitter bromine‐76. [76Br]4‐Bromodexetide, [76Br]BrDEX, and [76Br]4‐bromolevetimide, [76]BrLEV, were prepared via electrophilic bromodesilylation of 4‐(trimethylsilyl)dexetimide and 4‐(trimethyylsilyl)levetimide with [76Br]NH4. The use of chloramine‐T in acid media resulted in radiochemical yields of 80%. The radiotracers were purified by semi‐preparative reverse‐phase HPLC. Radiochemical and chemical purities were assessed by radio‐TLC and HPLC and found to be 98%. The average time of synthesis including formulation was 60 minutes resulting in average specific activitie

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360308

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractA new method for the preparation of d1‐benzaldehydes from α‐keto acids in 2 steps is repo

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360309

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractThe title compound [14C]BAY w 6341 was synthesized as part of a 4‐step sequence. Starting from diethyl [2‐14C]malonate the final product (8) was obtained with a specific activity of 1.2 GBq/mmol (32.9 mCi/mmol) and a radiochemical purity of>99 % in an overall yield of 1

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360310

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY

摘要:

AbstractAromatic amino groups are replaced with deuterium via a diazonium salt intermediate. Dimethylformamide‐d7is the deuterium donor in this mild replacement method that yields aromatic‐d1products in high isotopic purity. The presence of methyl groups lowers the isotopic purity of the produ

ISSN:0362-4803    

DOI:10.1002/jlcr.2580360311

出版商:John Wiley&Sons, Ltd.    

年代:1995

数据来源: WILEY