摘要:

AbstractDans ce travail, on décrit la préparation et les propriétés de plusieurs acides dérivés du thiophène, du 2‐bromothiophène, des 2 thiotolénes, et du 2,5‐diméthylthiophène. Les méthodes utilisées pour préparer ces acides sont l'oxydation des méthylcétones par l'hypobromite de Na, pour les acides nucléaires, et la réactionde Willgerodtpour les acides à carboxyles extranucléaires. De nombreuses amides substituées dérivant de ces divers acides ont été préparées et comparées avec leurs isologues appartenant aux séries benzénique et furanique. A partir des chlorures de certains de ces acides et au moyen de la réaction deFriedel‐Crafts, on a préparé une série de cétones nouvelles, dont certaines ont été converties en α, β, β‐triaryléthènes à noyau thiophène. Avec les mêmes chlorures d'acides et les magnésiens du pyrrol et de l'indol, on a obtenu de nombreuses cétones, dont certaines ont pu être méthylées à l'azote. Quelques autres composés hétérocycliques azotés à noyau thiophène (benzacridines, phénanthridines, benzimidazols) ont aussi été synthétisés; des isologues furaniques de plusieurs des substances ci‐dessus ont été préparés à titre comparatif. Enfin, la chlorométhylation du 2,5‐thiox

ISSN:0165-0513    

DOI:10.1002/recl.19490680102

出版商:WILEY‐VCH Verlag    

年代:1949

数据来源: WILEY

摘要:

AbstractThe curves of partial miscibility of the system methylmethacrylate‐methanol‐water have been determined at 0°, 25° and 50° C, as well as the variation of the density at 25° along the curve of partial miscibility. A graph has been constructed on this basis, which gives the composition of the two coexisting phases of the system from the density of one of the phases. The critical solubility point at 25° C is situated at 32.45% methanol. 38.50% methylmethacrylate and 29.0

ISSN:0165-0513    

DOI:10.1002/recl.19490680103

出版商:WILEY‐VCH Verlag    

年代:1949

数据来源: WILEY

摘要:

AbstractA method is worked out according to which a separate determination of aldoses, fructose, sucrose and fructosan in grass is possible.The contents of these substances in relation to the age of the grass are determined; the fructosan content passed through a peak.Evidence was obtained that the sucrose content was highest on bright sunny days.Sucrose appeared to be the only carbohydrate which showed a distinct diurnal variation.

ISSN:0165-0513    

DOI:10.1002/recl.19490680104

出版商:WILEY‐VCH Verlag    

年代:1949

数据来源: WILEY

摘要:

AbstractThe binary melting‐point diagram of the two isomeric ketones C5Cl6O was determine

ISSN:0165-0513    

DOI:10.1002/recl.19490680105

出版商:WILEY‐VCH Verlag    

年代:1949

数据来源: WILEY

摘要:

Abstract3‐Nitrobenzene‐(1 azo 4)‐1‐naphthol has been examined, as contradictory data concerning it are found in the lit

ISSN:0165-0513    

DOI:10.1002/recl.19490680106

出版商:WILEY‐VCH Verlag    

年代:1949

数据来源: WILEY

摘要:

AbstractMany contradictory data are known concerning the alkalimetric titration of phosphoric acid. The uncertainties, which have received a solution in this investigation, concern:1the correct titration exponent in titration to mono or diphosphate;2the correct composition of crystalline disodium phosphate which turned out to be exactly Na2HPO4. 12H2O;3the inflexion points in the titration curve were found to coincide with the equivalence points.Further a search was made for a suitable and accurate method of carrying out an alkalimetric phosphate determination in phosphates containing calcium, aluminium and iron, because the known methods are all unreliable. A removal of the disturbing metallic ions with the aid of a cation exchanger was found to be the solution. An attempt was made, but without ultimate success, to exclude disturbing fluoride and silicofluoride.The demands, which must be made in alkalimetric titrations on the purity of distilled water, have been sorted out and summarised.

ISSN:0165-0513    

DOI:10.1002/recl.19490680107

出版商:WILEY‐VCH Verlag    

年代:1949

数据来源: WILEY

摘要:

AbstractBy the electrolytic reduction of pyridine 2‐ and 4‐carboxylic acids respectively at a lead or mercury cathode, 2‐ and 4‐methylpyridine, respectively have been obtained in yields of 30‐35%. The reduction product from pyridine 3‐carboxylic acid has not yet been

ISSN:0165-0513    

DOI:10.1002/recl.19490680108

出版商:WILEY‐VCH Verlag    

年代:1949

数据来源: WILEY

摘要:

AbstractThis paper contains data on the rates of “catalytic” deacylation of derivatives ofortho‐ andpara‐nitro‐acetanilide in which steric effects on mesomerism are absent, especially 1‐acetylamino‐2‐nitro‐4‐R‐benzene, 1‐acetyl‐amino‐2‐nitro‐5‐R‐benzene and 1‐acetylamino‐4‐nitro‐6‐R‐benzene. Comparison of these rates with those ofortho‐ orpara‐nitro‐acetanilide gives the (“direct”) influence of the respective substituents inpara‐, meta‐ andortho‐position to the acetylamino group. The results, which will be used in subsequent papers, are nearly

ISSN:0165-0513    

DOI:10.1002/recl.19490680109

出版商:WILEY‐VCH Verlag    

年代:1949

数据来源: WILEY

摘要:

AbstractThis paper contains data on the (pseudo) catalytic deacylation of a number of derivatives ofortho‐nitro‐acetanilide in which steric effects on mesomerism are to be expected. The rate of deacylation found for each compound is discussed in some detail on the basis of current electronic theory.It is shown that the occurrence of steric inhibition of mesomerism can sometimes be used to advantage in the separation of mixtures of isomeric nitroaryl‐acyla

ISSN:0165-0513    

DOI:10.1002/recl.19490680110

出版商:WILEY‐VCH Verlag    

年代:1949

数据来源: WILEY

ISSN:0165-0513    

DOI:10.1002/recl.19490680101

出版商:WILEY‐VCH Verlag    

年代:1949

数据来源: WILEY