摘要:

AbstractAniline (IV), specifically13C labeled in the 4‐ or in the 3,5‐position (IVa and IVb), has been synthesized with 55% yield from13C labeled p‐nitrophenol (II). The reduction of the NO2group and the removal of the OH group was performed in one step by reduction and hydrogenolytic cleavage of p‐nitrophenol‐methanesulfonate (III), prepared in 90% yield from (II). From (IV) a number of specifically13C labeled monosubstituted benzenes C6H5Y (Y = CN, Hal, NO2) are easily a

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240302

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractSeveral synthetic routes to the two title compounds are presented. S‐Benzyl‐[18O3]phosphorothioate was synthesised in 68% yield from phosphorus trichloride. Adenosine 5′‐[18O3]phosphate was synthesised in two steps from adenosine in 44

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240303

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractPropylproline and N‐demethyl‐lincomycin, two intermediates in lincomycin biosynthesis, were prepared in radiolabeled form. [14C]‐labeled N‐demethyl‐lincomycin was synthesized by a resting cell suspension of a lincomycin negative mutant ofStreptomyces lincolnensisthat was fed methylthiolincosaminide and uniformly labeled [14C]‐tyrosine. [14C]‐N‐demethyl‐lincomycin was isolated from the culture medium by ion exchange chromatography and reverse phase‐ion pair high pressure liquid chromatography. [14C]‐propylproline was generated by the base hydrolysis of [14C]‐N‐demethyl‐lincomycin and isolated by anion exchange chromatography. The products had radiochemical purities greater than 95% and specific

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240304

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe extension of the N‐permethylation reaction of amines to aromatic amines with strong electron withdrawing substituents in o‐ and p‐ positions is reported. A comparison of this method with other “best” last step synthetic methods reported in literature is given. The reaction could be extended to the syntheses of N‐permethyl‐derivatives of amines of the type CH3‐nDnby use of formaldehyde, dideuteroformaldehyde, sodium borodeuteride and ‐hydride. Label conservation in the reaction is complete: the final step in the reaction involves H−(or D−) transfer from the reducing agent to a reactive species. The MS of the labelled compounds revealed extensive label excange in the ionization chamber. A new homogeneous procedure for the N‐permethylation, especially suited for larger scale pre

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240305

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThe synthesis of tritium labelled 2‐(3′‐carboxypropyl)‐3‐imino‐6‐para‐methoxyphenyl‐2,3‐dihydropyridazine, a new, specific, water‐soluble and chemically stable GABA antagonist at the GABAAreceptor site is reported. The synthesis involves an N‐2 endo‐alkylation of 3‐amino‐6‐p‐methoxyphenyl‐pyridazine with ethyl γ‐bromocrotonate, reductive tritiation of the crotonic doubl

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240306

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractThis article describes a three step‐selective deuteration method of 1‐methyl and 3‐methylxanthine, after protection of the N‐7 position by chloromethylpivalate and alkylation by trideuteromethyl iodide; yielding 1‐C2H3and 3‐C2H3t

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240307

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractA semi‐synthetic method for the preparation of deuterated leukotriene B4(2H8‐LTB4) from eicosatetraynoic acid (ETYA) is described which involves reduction of ETYA to deuterated arachidonic acid (2H8‐AA) with deuterium gas and then biological conversion of this material to2H8‐LTB4by rat peritoneal polymorphonuclear leukocytes

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240308

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractSynthesis and chromatographic separation of (E) and (Z) isomers of (ring‐U‐14C) hexanal phenylhydrazone2: (ring‐U‐14C) phenylhydrazine hydrochloride 1 was synthesized from labelled aniline hydrochloride, and purification was accomplished by reverse phase low pressure liquid chromatrography. The crude free base of1was condensed with hexanal to give a mixture of (E) and (Z) isomers of2. The conditions for their separation by reverse phase HPLC were optimized on an analytical column and then used for the preparative work which was the most effective and fastest method.Structure and configuration of (E) and (Z) isomers of (ring‐U‐14C) hexanal phenylhydrazone (SA = 13.3 mCi/mmol) were proven by1H‐NMR and mass

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240309

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractPreparations of specifically labeled α‐ and γ‐[14C]allyl phenyl ether are desc

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240310

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY

摘要:

AbstractHomovanillic acid (4‐hydroxy‐3‐methoxyphenylacetic acid) was labeled with tritium by exchange reaction in tritiated water catalyzed by sulfuric acid. The product was obtained in good yield and specific activities sufficient be utilized in metabolic experiments. Reactions carried out under identical conditions, but in the presence of deuterated water gave a product in which all the aromatic hydrogens and those α ‐ to the carboxyl group were replaced with deuterium indicating that the tritium‐labeled homovanillic acid was labeled in these

ISSN:0362-4803    

DOI:10.1002/jlcr.2580240311

出版商:John Wiley&Sons, Ltd.    

年代:1987

数据来源: WILEY