摘要:

AbstractThe radiochemical synthesis of a κ‐subtype opiate receptor ligand, [11C](±)U‐50488H, was accomplished either in two steps or by direct methylation with [11C]iodomethane. The radiotracer was purified using reversed phase semipreparative HPLC. The average specific activity was 1830 mCi/μmole (calculated at the end‐of‐synthesis; EOS) for the direct methylation and 2140 mCi/μmole EOS for the two‐step one‐pot synthesis. The average time of synthesis including formulation was approximately 22 minutes for the direct methylation and 27 minutes for the two‐step

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310202

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe synthesis of polyethylene glycols [α‐Hydro‐ω‐hydroxypoly(oxy‐1, 2‐ethanediyl)‐dx], deuterated in the chain, up to the lenght of the chain of 20 carbons was achieved by reaction of ethylene glycol‐d, with iodi

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310203

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractWe have developed a stereoselective route to isotopically labeled L‐aspartic acid using L‐serine as a chiral precursor. Labeled serine, prepared biosynthetically was N‐protected by conversion to the N‐t‐Boc derivative. (N‐t‐Boc)‐[3−13C]Serine is cyclized to its β‐lactone which was treated with potassium [13C]cyanide to yield L‐β‐[3,4−13C2]cyanoalanine. Hydrolysis of the cyanoalanine yielded L‐[3,4−13C2]aspartic acid. Similarly, L‐[4−13C]aspartate was produced from L‐serine and K13CN. Using this route, the L

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310204

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractUtilizing sodium [1−14C]propionate as a precursor, [14C]FK‐506, labeled at carbon atoms 10, 16, 18, 21a, 24, and 26, was produced by fermentative biosynthesis. Extractive isolation followed by chromatographic purification provided material of purity suitable for metabolism stud

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310205

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe synthesis of [1,3,5‐13C3]‐ and [2,4,6,7‐13C4]benzoic acid (5aand5b) from [2‐13C]‐ and [3‐13C]sodium pyruvate (1aand1b), forin vitroandin vivotracer studies using13C nuclear magnetic resonance (NMR) spectroscopy, is reported. After condensation of1to [13C]methyldihydrotrimesic acids2using sodium hydroxide, decarboxylation to [13C]uvitic acid3was carried out using conc. sulfuric acid. Additional decarboxylation of3was achieved with cupric oxide and quinoline, and the resulting [13C]toluenes4were effectively trapped, using a simplified decarboxylation apparatus. Compounds4were subsequently oxidized to5using potassium permanganate without further purification. The overall yields of5from1were 26–28 %, with isotopic purities of 96–98 %. In addition, the assignments for13C NMR signals of benzoic acid were firs

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310206

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractS‐γ‐[(4‐Trifluoromethyl)phenoxy]benzenepropanamine‐[1‐14C] maleate has been prepared in six steps fromR‐(‐)1‐phenyl‐1,2‐ethanediol. The isotope was incorporated by the reaction of NaCN‐[14C] with thetert.butyldimethylsilyl ether ofR‐(‐)1‐phenyl‐1,2‐ethane‐diol 2‐tosylate. Borane reduction and arylation, followed by salt formation yieldedS‐γ‐[(4‐trifluoromethyl

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310207

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

Abstract14C‐Labeled 1,2‐dihydro‐5‐imidazo [1,2‐a]pyridin‐6‐yl‐6‐methyl‐2‐oxo‐3‐pyridinecarbonitrile hydrochloride monohydrate6was synthesized in 5 steps from 6‐bromoimidazo [1,2‐a] pyridine using [2‐14C] cyanoacetamide as the source of the radiolabel. The key intermediate, 1‐imidazo [1,2‐a] pyridin‐6‐yl‐2‐propanone3was prepared by the selective ozonolysis of the propenyl group of 6‐(2‐methylpropen‐3‐yl) imidazo [1,2‐a] pyridine2under acidic conditions followed by the reduction with sodium sulfite. The chemical yield of6from 4‐dimethylamino‐3‐imidazo‐[1,2‐a]pyridin‐6‐yl‐3‐buten‐2‐one4and the radiochemical yield from [2‐14C] cyanoacetamide were both 57%. The radiochemical p

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310208

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractThe synthesis of an isotopically labelled terpene synthon (4) is described. The usefulness of this terpene synthon in the synthesis of Δ1‐THC metabolites is shown by preparation of (±)‐[2H10]‐Δ1‐THC‐7‐oic acid (5) by condensation of4with [2H7]‐olivetol. Compound5is suitable as internal standard for mass spec

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310209

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractAn enzymatic method is described which makes it possible to synthesize labelled purine deoxyribonucleotides from corresponding labelled purine ribonucleotides using the RDP‐reductase system of ether‐treated E. coli E125 ce

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310210

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY

摘要:

AbstractImproved procedures for the radiosynthesis of α‐[11C]methyltryptophan and α‐[11C]methyl‐tryptophan methyl ester were studied. Following α‐deprotonation of tryptophan methyl ester benzaldimine with LDA, 60 – 80% of no carrier added [11C]iodomethane was incorporated in 5 minutes at 27 – 30°C. After HPLC purification, radiochemically pure α‐[11C]methyl‐tryptophan or its methyl ester was produced with minimum chemical contamination from tryptophan. The [11C]methyl‐tryptophan synthesized, however, was

ISSN:0362-4803    

DOI:10.1002/jlcr.2580310211

出版商:John Wiley&Sons, Ltd.    

年代:1992

数据来源: WILEY