摘要:

AbstractThe current‐voltage curves of various alternant and non‐alternant hydrocarbons were measured in 75% and 96 % dioxane‐water. In many cases the limiting current of the first reduction wave corresponds to the overall addition of one electron. From the effect of the increase of the percentage of water and the addition of hydrogen iodide on the limiting current and on the half‐wave potential of the first and the second wave, evidence was obtained about the reduction mechanism. The primary steps of the reduction are: R + e →←R′ and R′ + e →←R″ the standard potential determined by the first electron addition is less negative than that of the second step.When the rate of proton addition to R′ is low with respect to the rate of diffusion of R′, the first wave is a one‐electron wave and the second wave involves the reduction to R″. When R′ reacts with a proton in the electrode surface layer, the reduction proceeds according to:The reduction mechanism is discussed in detail and compared with the experimental results reported in this paper

ISSN:0165-0513    

DOI:10.1002/recl.19540730502

出版商:WILEY‐VCH Verlag    

年代:1954

数据来源: WILEY

摘要:

AbstractOn montre que la condensation deTschitschibabindes esters maloniques monosubstitués avec la 2‐aminopyridine et la 4‐méthyl‐2‐aminopyridine n'est pas entravée par la présence de radicaux encombrants dans la molécule de ces esters, et que l'on aboutit, dans tous les cas examinés, aux dérivés de l'homopyrimidazole attendus. Ces observations plaident en faveur de l'hypothèse selon laquelle le mécanisme de la condensation deTschitschibabincomporte l'intervention des formes énoliques des

ISSN:0165-0513    

DOI:10.1002/recl.19540730503

出版商:WILEY‐VCH Verlag    

年代:1954

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19540730504

出版商:WILEY‐VCH Verlag    

年代:1954

数据来源: WILEY

摘要:

AbstractA combustion method for accurate isobutanol determination in dilute aqeous solutions, to be used for serial determinations, is given.

ISSN:0165-0513    

DOI:10.1002/recl.19540730505

出版商:WILEY‐VCH Verlag    

年代:1954

数据来源: WILEY

摘要:

AbstractAfter a historical review of the development of goniometers for crystal measurements, a description is given of an improved, modernized construction.It is emphasized that the instrument in its present form can be used for routine measurements without difficulty by any chemist with a minimum of crystallographic knowledge.

ISSN:0165-0513    

DOI:10.1002/recl.19540730506

出版商:WILEY‐VCH Verlag    

年代:1954

数据来源: WILEY

摘要:

AbstractThe synthesis of vitamin D33 C14is described. Special attention has been paid to the technique of the photochemical conversion of 7‐dehydro‐cholesterol 3C14(small quantities) and to the isolation of the labelled vitamin D3from the irradiation mixture. Some biological experiments are briefly communica

ISSN:0165-0513    

DOI:10.1002/recl.19540730507

出版商:WILEY‐VCH Verlag    

年代:1954

数据来源: WILEY

摘要:

AbstractZur Prüfung der bactericiden Wirkung von quaternären Bis‐(2‐oxyäthyl)‐ammonium‐verbindungen mit höheren Kohlenwasserstoffresten wurden Decyl‐, Hexadecyl, Octadec‐9‐enyl, 11‐Cyclopent‐2′‐enyl‐n‐undecyl‐ und 13‐Cyclopent‐2′‐enyl‐n‐tridecyl‐bis‐(2″‐oxyäthyl)‐amine und die entsprechenden Amine, welche die den im Chaulmoograöl vorhandenen Fettsäuren entsprechenden Reste enthalten, hergestellt und mit Benzylchlorid umgesetzt.Diese quaternären Ammonium‐salze besitzen eine hohe bactericide Wirksamkeit. Sie töten innerhalb von 2.5 Minuten S. aureus

ISSN:0165-0513    

DOI:10.1002/recl.19540730508

出版商:WILEY‐VCH Verlag    

年代:1954

数据来源: WILEY

摘要:

AbstractTo aconic acid, first described in literature byKekulé, the structure of a β,γ‐butenolide was given byFittigandBeer.In 1947CampbellandHuntput forward arguments for an α,β‐butenolide structure. These arguments were based on a new synthesis of the acid and a comparison of the U.V. absorption spectrum of aconic acid with those of mesaconic acid and itaconic acid. Close inspection of the properties of aconic acid shows however thatCampbellandHunt's synthesis of aconic acid is not proving for its structure.Moreover these authors drew their spectral conclusions only from curveshapes, so we found it necessary to repeat the U.V. measurements at lower wave lengths. The rightness of the structure proposed byCampbellandHuntcould b

ISSN:0165-0513    

DOI:10.1002/recl.19540730509

出版商:WILEY‐VCH Verlag    

年代:1954

数据来源: WILEY

摘要:

AbstractFrom aconic acid with an excess of diazomethane a nitrogen‐containing compound is formed. The structure was established to be methyl 3,4‐(4′,5′‐Δ1‐pyrazolino) aconate. Heating of this compound resulted in the splitting off of a molecule of nitrogen and the formation of a methyl‐substituted aconic acid ester hitherto unknown in

ISSN:0165-0513    

DOI:10.1002/recl.19540730510

出版商:WILEY‐VCH Verlag    

年代:1954

数据来源: WILEY

摘要:

AbstractIn view of the lack of any systematic work already mentioned in the literature on the Hofmann reaction with amides containing two or more simple aryl groups in α‐ or β‐position, work was taken up on the Hofmann rearrangement of diphenylacetamide and ββ‐diphenylpropionamide, to serve as examples of αα‐ and ββ‐arylaliphatic amide respectively. Results indicated that while no special difficulty was encountered with ββ‐diphenylpropionamide, diphenylacetamide could be converted to the corresponding amine only in a more concentrated alkali solution than is customarily employed.Experiments carried out to ascertain the optimum conditions for the successful Hofmann rearrangement of diphenylacetamide yielded, in dilute alkali solution, a new secondary reaction product – a Schiff's base,viz.N‐benzhydryl‐benzophenone‐imine, instead of the expected benzhydryl‐amine. A theoretical explanation has been submitted in support of this abnormal observation.Benzhydrylamine has also been obtained through the Lossen rearrangement of N‐benzoyl‐diphenylacethydroxamic acid in about 20% yield; a by‐product,viz.N‐Nî‐di

ISSN:0165-0513    

DOI:10.1002/recl.19540730511

出版商:WILEY‐VCH Verlag    

年代:1954

数据来源: WILEY