摘要:

AbstractLa carbonatation avec14CO2du Mméthylthiométhyllithium a fourni l'acide méthylthio‐2 acétique(14C‐1) avec un rendement de 83%, dont la réduction par LiA1H4a conduit au méthylthio‐2 éthanol‐1 (14C‐1) qui a été transformé en chlorure correspondant par action de la tri‐n‐octylphosphine et CCl4. Le chlorure condensé sur le sodio acétamicomalonate d'éthyle a fourni le (méthylthio‐2 éthyl) acétamidomalonate d'éthyle (14C03) qui a été saponifié en monoester dont la décarboxylation a produit le DL‐méthylthio‐4 acétamido‐2 butyrate d'éthyle (14C‐3). L'hydrolyse par l'α‐chymotrypsine donne la N‐acétyl‐L‐méthionine (14C‐3) que l'on sépare du méthylthio‐4 acétamido‐2‐D‐butyrate d'éthyle (14C‐3). Par hydrolyse chlorhydrique on aboutit respectivement à la L‐méthionine (14C‐3) et à la D‐méthionine (14C‐3) dactivité spécif

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100112

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractThe exchange reaction of carboxyl groups with carbon dioxide has been studied in thermal decomposition of aliphatic dicarboxylic acid disodium salts. It has been found that exchange takes place under given experimental conditions. In some cases the process results in considerable exchange even in lower conversion ranges therefore it is of significance in the field of isotopes techniques.

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100113

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractDi‐(1,3‐dimethylbut‐2‐enyl‐[4‐3H1]mono‐, di‐and trisulphides have been synthesised via the common intermediate S‐(1,3‐dimethylbut‐2‐enyl‐[4‐3H1] thiouronium bromide (I). Protonation of a mixture of 2‐methylpenta‐1,3‐and ‐2,4‐dienes during formation of (I) was shown to be accompanied by a large kinetic isotope effect such that protonation was 8–

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100114

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractN‐(Feruloyl‐2‐14C)‐glycine‐2‐3H (IX) was obtained with an acceptable yield (43%) starting from O‐methoxycarbonyl‐ferulic acid‐2‐14C (IV) and glycine‐2‐3H ethyl ester (VI). The latter two compounds were first condensed into N‐(O‐methoxycarbonyl‐feruloyl‐2‐14C)‐glycine ‐2‐3H ethyl ester (VII) using anisoyl chloride (X) and the mixed anhydride method (?). Subsequently VII was transformed into N‐(feruloyl‐2‐14C)‐glycine‐2‐3H (IX) by alkaline hydrolysis. The specific activities of the compound were respect

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100115

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractThe syntheses of 3‐methyl‐4‐phenyl‐3‐butenamide, an hypolipemic compound, labelled 1‐14C (VIII) and N,N‐dideutero (XI) are described. The 2‐methyl‐3‐phenyl‐2‐propenyl chloride (VI), reacting with cuprous cyanide‐14C, gave the 3‐methyl‐4‐phenyl‐3‐butenonitrile‐1‐14C (VII) which, treated with hydrochloric acid‐water, gave the 3‐methyl‐4‐phenyl‐3‐ butenamide‐1‐14C (VIII). The 3‐methyl‐4‐phenyl‐3‐butenonitrile (X), treated with hydrochloric aci

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100116

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractThe preparation of 2, 6‐dimethoxy [U‐14C]phenol was carried out in five steps from [U‐14C]phenol. [U‐14C]Phenol was converted to 2‐[U‐14C]phenoxy‐5‐nitrobenzophenone which was sequentially hydroxylated with hydrogen peroxide‐acetic acid to give the di‐orthohydroxylated phenolic intermediate, 2‐(2′',6″‐dihydroxy [U‐14C]phenoxy)‐5‐nitrobenzophenone. Methylation of this intermediate and subsequent scission of the aryl ether link with piperidine gave the required di‐orthosubstituted phenol. An alternative sequence was investigated for the conversion of 2‐(2″‐hydroxy‐phenoxy)‐5‐nitrobenzophenone to 2‐(2″,6″‐dimethoxyphenoxy)‐5‐nitrobenzophenone but it gave a poorer overall yield with a

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100117

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100118

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

Abstractα‐Dihydrograyanotoxin II has been labelled with tritium at the C‐10 and C‐19 positions by catalytic hydrogenation of grayanotoxin II. Pd‐catalyzed reduction in tetrahydrofuran produced the α‐form exclusively. The compound was obtained with specific activity 1.21 Ci/mmole and with 99% radio‐ch

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100119

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100120

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY

摘要:

AbstractInterest in labeled compounds which can be studied as brain metabolites and can be detected in vivo has led to production of carbon‐11 labeled acetoacetic acid (1‐11C‐acetoacetic acid). This synthesis, which was designed specifically for use with short‐lived isotopes, utilizes a solution of the stable enolate anion of acetone, generated by the reaction of CH3Li and isopropenyl acetate, to which the11CO2is added to produce the labeled acetoacetic acid in ∼55% yield with a synthesis time of only 40 minutes from the end of bo

ISSN:0022-2135    

DOI:10.1002/jlcr.2590100121

出版商:John Wiley&Sons, Ltd.    

年代:1974

数据来源: WILEY