摘要:

AbstractSulphur retards the autoxidation of pinene and benzaldehyde and thereby impedes the formation of peroxides. The sulphur is found to be oxidized in a small measure.

ISSN:0165-0513    

DOI:10.1002/recl.19460650102

出版商:WILEY‐VCH Verlag    

年代:1946

数据来源: WILEY

摘要:

AbstractA proof is given that in the condensation product formed by the interaction of malonic ester and β‐aminocrotonic acid ester, namely 2‐methyl‐4,6‐dihydroxypyridine‐carboxylic acid ester, the COOC2H5‐group occupies the 5‐position.This was effected by exchanging the hydroxyl groups for chlorine atoms and subsequently replacing these atoms by hydrogen atoms. The structure of the resulting 2‐methylpyridine‐carboxylic acid ester was established by conversion into the corresponding picrate, carboxylic acid and amide. The identities of these compounds with 2‐methylpyridine‐5‐carboxylic acid ester‐picrate, 2‐methylpyridine‐5‐carboxylic acid and ‐amide were proved by mixed melting points with samples of these substances prepa

ISSN:0165-0513    

DOI:10.1002/recl.19460650103

出版商:WILEY‐VCH Verlag    

年代:1946

数据来源: WILEY

摘要:

AbstractA differential formula is derived, with the aid of which it is possible to compute the mean radius of the particles of a substance whose density and refractive index are known at different values of the temperature or of the pressure.

ISSN:0165-0513    

DOI:10.1002/recl.19460650104

出版商:WILEY‐VCH Verlag    

年代:1946

数据来源: WILEY

摘要:

AbstractFrom measurements of the refractive index and the density of aqueous electrolyte solutions, the radius and the polarizability of the ions Cl−, Br−, I, NO3−, ClO4−, SO4−, NH4+, Rb+, Cs+, Sr++and Ba++are calculated, also the polarizability of the ions Na+, K

ISSN:0165-0513    

DOI:10.1002/recl.19460650105

出版商:WILEY‐VCH Verlag    

年代:1946

数据来源: WILEY

摘要:

AbstractThe complicated deviations from the additivity of the molecular refraction found in electrolyte solutions by Fajans and his collaborators, appear to be the simple consequence of the correction introduced by the author in the Lorentz‐Lorenz formul

ISSN:0165-0513    

DOI:10.1002/recl.19460650106

出版商:WILEY‐VCH Verlag    

年代:1946

数据来源: WILEY

摘要:

AbstractFrom some examples it will be shown that it is possible with the aid of a formula derived by the present writer to compute with a high degree of accuracy the index of refraction of an aggregate from the radii and the polarizabilities of the particles of which it is composed.

ISSN:0165-0513    

DOI:10.1002/recl.19460650107

出版商:WILEY‐VCH Verlag    

年代:1946

数据来源: WILEY

摘要:

AbstractL'oxydation prudente du tétrathioorthocarbonate de méthyle ne donne pas la tétrasulfone correspondante, mais une trisulfone, le tris‐méthylsulfonyl‐méthane. Nous avons essayé d'introduire dans cette trisulfone un quatrième groupe méthylsulfonyle ou un groupe thioéther, que l'on pourrait oxyder ensuite. La réaction du méthylmercaptide et du chlorure méthylsulfonique sur le bromo‐tris‐méthylsulfonyl‐méthane a régénéré la trisulfone. La réaction entre un sulfinate d'argent et le dérivé sodique de la trisulfone n'a pas don

ISSN:0165-0513    

DOI:10.1002/recl.19460650108

出版商:WILEY‐VCH Verlag    

年代:1946

数据来源: WILEY

摘要:

AbstractL'action dup‐nitrobenzènesulfochlorure sur la guanidine en solution faiblement alcaline produirait, selon Winnek, une sulfonamide (lap‐nitrophénylsulfonyl‐guanidine), tandis que Karrer et Epprecht ont obtenu un sel (lep‐nitrobenzènesulfonate de guanidine). Une étude détaillée de cette réaction nous a permis d'expliquer cette différence de résultat. Les observations des auteurs précités sont, toutes les deux, correctes, mais incomplètes. Le produit principal est, soit la sulfonamide, soit (en solution plus alcaline) le sel. Mais, à cǒté de la sulfonamide, il se forme, en quantité notable, une disulfonamide (la bis‐p‐nitrophénylsulfonyl‐guanidine) et, en milieu assez alcalin (K. et E.), on obtient les produits de décomposition des deux sulfonamides.Lap‐nitrophénylsulfonyl‐guanidine engendre, en solution alcaline, lap‐nitrophényl‐guanidine; la bis‐p‐nitrophénylsulfonyl‐guanidine donne naissance à des quantités équimoléculaires dep,p'‐dinitrophényl‐amine et de cyanamide. II se forme, dans les deux cas, la quantité théorique d'anhydride sulfureux.En vue de la comparaison, les auteurs ont examiné ensuite l'action des deux nitrobenzènesulfochlorures isomères (o etm) sur la guanidi

ISSN:0165-0513    

DOI:10.1002/recl.19460650109

出版商:WILEY‐VCH Verlag    

年代:1946

数据来源: WILEY

摘要:

AbstractCe mémoire décrit la préparation et les propriétés de la disulfanilyl‐guanidine. Son activité antibactérienne “in vitro” est plus faible que celle de la sulfanilyl‐guanidine. “In vivo” elle ne prés

ISSN:0165-0513    

DOI:10.1002/recl.19460650110

出版商:WILEY‐VCH Verlag    

年代:1946

数据来源: WILEY

摘要:

AbstractFrom the seeds of Leucaena glauca B, obtained from the Netherlands Indies, we isolated leucaenine which, under the name leucaenol, was first described in 1937 by Mascré, who determined for this compound the empirical formula C4H5O2N. We obtained about 16 g of pure leucaenine (melting point 226°–227° with decomposition) from 1 kg of seeds.From an electrometrical titration the molecular formula of the substance is found to be C8H10O4N2; leucaenine is an α‐amino acidin the molecule of which apyridine ring substituted by hydroxyl occurs. By the action of dimethyl sulphate and alkali on leucaenine we obtained a compound C7H11O3N (I) which could be converted into a N‐methylhydroxypyridone having the composition C6H7O2N (II). This compound is not identical with N‐methyl‐6‐hydroxypyridone‐2 or with N‐methyl‐3‐hydroxypyridone‐2, which hitherto unknown pyridones were obtained by synthesis, and it is likewise not identical with the N‐methyl‐4‐hydroxypyridone‐2 (or N‐methyl‐2‐hydroxypyridone‐4) described by Späth. To the compound C6H7O2N therefore the structure of an N‐methyl‐3‐hydroxypyridone‐4 or of an N‐methyl‐5‐hydroxypyridone‐2 must be assigned; for the present we consider the first structure mentioned the more probable.Leucaenine itself must be considered as a β‐[hydroxypyridyl‐oxy] ‐α‐aminopropionic acid; the positions at which the hydroxyl group and the serine radical are substituted in the pyridine nucleus have not yet been determined, although it follows from our investigation that several positions are impossible. The most probable formula for leucaenine is in our opinion: β‐[3‐(4‐hydroxypyridyl)‐oxy]‐α‐aminopropionic acid. Since the compound isolated by us must therefore be classed among the naturally occurring amino acids we propose to call this substanceleucaenine.The substancemimosineisolated by Renz and by Nienburg and Tauböck from the leaf stems of Mimosa pudica L. and of Leucaena glauca B is very probably identical withleucaenine.From experiments on animals it was found that the administering of leucaenine or of seeds of Leucaena glauca B to rats or mice did not cause the hair to fall out. This result is not in agreement with several statements in the literature, according to which larger mammals, such as hors

ISSN:0165-0513    

DOI:10.1002/recl.19460650111

出版商:WILEY‐VCH Verlag    

年代:1946

数据来源: WILEY