摘要:

AbstractA new procedure has been developed for the synthesis of14C‐labeled glutethimide with an improved yield from K14CN. In this procedure benzyl cyanide prepared from benzyl chloride and K14CN was almost quantitatively monoethylated by an ion‐pair extraction method using 50% excess of tetrabutylammonium hydroxide as the catalyst. Michael addition of methyl acrylate to monoethylbenzyl cyanide followed by hydrolysis with H2SO4gave glutethimide which was then nitrated (HNO3+ H2SO4) and catalytically reduced to aminoglutethimide. The best result was obtained when the intermediatepara‐nitroglutethimide was isolated in pure form by crystallization and then reduced in the presence of 10% Pd/C. When the nitration product (which was a mixture of isomers) was reduced without purification, isolation of purep‐aminoglutethimide was more difficult and the yield was muc

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210302

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractAn enzymatic method is described for the synthesis of11C‐labelled (−)‐epinephrine in which the [11C]methyl group is sequencially transferred from L‐[methyl‐11C]methionine to (−)‐norepinephrine via S‐adenosyl‐L‐[methyl‐11C]methionine respectively by the enzymes L‐methionine‐S‐adenosine transferase (M.A.T) and phenylethanolamine‐N‐methyl transferase (P.N.M.T). Chromatographically pure11C‐epinephrine having a specific activity approximately 200 Ci/mmol is obtained 35 minutes after the synthesis of the starting compound L‐[methyl‐11C]methionine.Preliminary results are presented for the dynamics of the distribution of the11C‐epinephrine in org

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210303

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractA practical 2‐step synthesis of 3‐amino‐1‐methyl‐5H‐pyrido[4,3‐b]indole‐1‐14C is described, starting from 2‐cyanomethyl indole and carbonyl‐la

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210304

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

Abstract[14C]‐Tolrestat(N‐[[5‐(trifluoromethyl)‐6‐methoxy‐1‐naphthalenyl]‐[14C]‐thioxomethyl]‐N‐methylglycine; [14C]AY‐27, 773), a new aldose reductase inhibitor, was prepared by incorporating [14C]carbon dioxide. The intermediate, 6‐methoxy‐5‐trifluoromethyl‐[1–14C]‐naphthoic acid, prepared by carbonation of the corresponding lithiated derivative, was condensed with sarcosine methyl ester hydrochloride, converted to the thioamide and hydrolyzed. [14C]Tolrestat, having a specific activity of 52.7 μCi/mg was obtained in 26% overall yield from [14C]barium carbonate a

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210305

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractCarbon‐14 and tritium labeled (1,4‐dioxaspiro[4.5]dec‐2‐ylmethyl)guanidine sulfate, or guanadrel sulfateGuanadrel sulfate is the USAN name for (1,4‐dioxaspiro[4.5]dec‐2‐ylmethyl) guanidine sulfate.(1) were synthesized. The carbon‐14 label was incorporated into the dioxolane ring portion of guanadrel sulfate. The tritium labels were introduced into the cyclohexane ring portion of the molecule, at the beta and gamma positions with respect to the ketal linkage. The ketal resulting from the reaction of the original 2‐cyclohexen‐1‐one with 3‐phthalimido‐1,2‐propanedial contained a double bond in the β‐γ position rather than the α‐β postion of the original 2‐cyclohexen‐1‐one. This double bond shift provided a convenient method of introducing tritium into the 3‐and 4‐positions of cyclohexanone. P

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210306

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractDeuterium labelled thiomuscimol (6) was synthesizedviacatalytic deuteration in strongly basic C2H3O2H‐2H2O (9:1) of 3‐methoxy‐4‐bromo‐5‐(N‐methoxycarbony Iaminomethyl)isothiazole (3). The replacement of bromine by deuterium was accompanied by partial exchange of the side chain methylene protons for deuterium and by complete reesterification of the methoxycarbonyl group. Acid catalyzed deprotection of the reduction product 3‐methoxy‐4‐[2H]‐5‐(N‐[2H]methoxycarbonylamino[2H]methyl)isothiazole (5) gave 6 with only minor loss of deuterium fro

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210307

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractHigh specific activity (43.7 Ci/mmol) D‐3‐(2‐naphthyl)‐[2,3,‐3H] alanine (7) was obtained by reduction of methyl 2‐N‐acetylamino‐3‐(2‐naphthyl) acrylate (5) with carrier free tritium in the presence of (Ph3P)3RhCl followed by enzymatic resolution and hydrolysis. Reductions of5and other substrates catalyzed by Pd/C afforded products of low to medium specific activity (0.1–17 Ci/mmol).A synthetic approach which maximizes the specific activity, guarantees specificity of label, and may be applied toward the preparation of any tritiated (or14C) peptide is suggested.The synthesis of the decapeptide [D‐3‐(2‐naphthyl)‐[2,3‐3H]alanine6]LHRH (12) at 45.7 Ci/mmol, using

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210308

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

摘要:

AbstractA low cost, high yield synthesis of tetrachloroisophthalo‐[14C]‐nitrile (TCIN) is described. Direct replacement of iodine in 3‐iodobenzonitrile using14C‐labeled cuprous cyanide, and vapour phase chlorination yields [14C]‐TCIN, with maximum utilisation of the radiolabel. Alternative and unsuccessful routes are also briefly

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210309

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY

ISSN:0362-4803    

DOI:10.1002/jlcr.2580210301

出版商:John Wiley&Sons, Ltd.    

年代:1984

数据来源: WILEY