bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cyclo‐isomérisation de quelques benzylallylsulfones et de la phénylallylsulfone (les propriétés du groupe sulfonyle VIII)
Authors: Backer H. J. , Dost N. 
Published: September 2010

AbstractLa benzylallylsulfone, chauffée avec de l'acide sulfurique concentré, donne un isomère cyclique, dérivé du benzothiacyclohexane.Afin d'étudier le mécanisme de cette cyclo‐isomérisation, les auteurs ont examiné l'influence de substituants dans le noyau aromatique. La présence de groupes nitro diminue la tendance à la cyclisation, ce qui s'accorde avec l'hypothèse qu'elle repose sur une substitution électrophile. Seules les nitro‐benzylallylsulfones o et p se cyclisent, et cela à des températures plus élevées. L'opposition de l'isomère m à la cyclisation peut étre imputée à l'effet désactivant du groupe nitro sur l'hydrogène qui devrait étre substitué.Les méthylbenzylallylsulfones, chauffées avec de l'acide sulfurique, ne subissent pas la cyclisation attendue, par ce qu'elles sont sulfonées. Une solution sulfurique de fluorure de borium s'est montrée un catalyseur très actif pour la cyclo‐isomérisation. En présence de ce catalyseur, le dérivé méthylé m se cyclise aisément à la température ambiante. La cyclisation de l'isomère o se produit moins facilement et celle de l'isomère p n'a pas réussi.La cyclisation de la phénylallylsulfone a donné un dérivé de thianaphtène.
On the state of oxalic acid dissolved in water
Authors: Snethlage H. C. S. 
Published: September 2010

AbstractAn apparatus for the determination of solubilities is described. The solubility of oxalic acid in water from 0°‐80° has been measured. The form of the temperature‐solubility curve shows that oxalic acid 2 aq. at the melting point is partially dissociated into anhydrous oxalic acid and water.From the solubilities at lower temperatures the heat of solution is calculated, correcting for the electrolytic dissociation. The value is in good accord with that which was found experimentally.It is concluded that in a solution of oxalic acid in water at temperatures below 70° practically all the molecules present are bound to (at least) two molecules of water, but that at higher temperatures an increasing dissociation into anhydrous acid and water takes place
Note sur l'acide 2,3,5‐Triiodo‐Benzoïque
Authors: Olivier S. C. J. , Combé W. P. 
Published: September 2010

AbstractOn a amélioré le mode de préparation de l'acide 2,3,5‐triiodobenzoïque, substance intéressante au point de vue physiologique. Le rendement qu'on obtient avec la nouvelle méthode est notablement supérieur aux rendements obtenus au moyen des diverses méthodes décrites jusqu'à présent.Pour le composé à l'état pur on a trouvé le point de fusion de 230.8°‐231.2°, tandis qu'on trouve dans la littérature des chiffres variant de 223°‐224° à 225‐227°.
Condensation products of β‐ionone with 2‐methyl‐ and 2,4‐dimethylpyridine: An attempt to synthesize vitamin a
Authors: Arens J. F. , van Dorp D. A. , van Dijk G. M. 
Published: September 2010

Abstractβ‐Ionone has been condensed with the lithium derivatives of α‐picoline and of 2,4‐dimethylpyridine to form the carbinols VI (R = H) and VI (a) (R = CH3).These condensation products were dehydrated with oxalic acid to VII. In the case of 2,4‐dimethylpyridine the polyene VII (R = CH3) was isolated in a cis and a trans form.The original purpose of these experiments was to hydrolyse the pyridine ring in order to obtain derivatives of vitamin A. This, however, could not be achieved. The bases as such had no vitamin A activity.The condensation products of α‐picoline with crotonic and sorbic aldehyde have also been prepared.
Colorants Polyméthiniques à Substitution Carboxylée dans la Chaîne
Authors: Bruylants P. , van Dormael A. 
Published: September 2010

AbstractLes auteurs décrivent la synthèse de carbocyanines asymétriques, de mérocarbocyanines et d'une rhodacyanine portant un groupement carboxyle ou carbalcoxy en position β de la chaîne, aux dépens de dérivés oxalylméthyléniques du benzothiazole. Les données optiques des nouveaux colorants sont renseignées.
Derivatives of triaza‐indolizines
Authors: Cook J. W. , Gentles R. P. , Tucker S. Horwood 
Published: September 2010

Abstract3‐Amino‐1,2,4‐triazole (I) has been found to react readily with suitable derivatives of cyclopentanone and cyclohexanone (for example, their hydroxymethylene derivatives and the corresponding keto‐esters) to form tricyclic compounds of the triaza‐indolizine class. The structural relationships between these various triaza‐indolizine derivatives are discussed.
Recherches sur les Alcaloïdes de L'erythrophleum: 13ème Communication): L'hydrolyse de la cassamine et de l'érythrophlamine
Authors: Engel B. G. , Tondeur R. , Ruzicka L. 
Published: September 2010

AbstractDans le mémoire qui précède, ainsi que dans deux brièves notesL. Ruzicka, Pl. A. Plattner, B. G. Engel, Experientia 1, 160 (1945); B. G. Engel et R. Tondeur, Experientia 4, 430 (1948).
), nous avons donné la description de deux alcaloïdes nouveaux tirés de l'écorce d'Erythrophleum et de leurs sels. Nous désirons maintenant décrire les résultats de l'hydrolyse de ces deux alcaloïdes.
Some observations on tetraethylthiuram disulphide
Authors: Fredga Arne 
Published: September 2010

AbstractTetraethylthiuram disulphide (antabuse, abinyl) has the character of a pseudo‐halogen. In organic solvents it reacts with several metals giving salts of diethyldithiocarbamic acid. Copper gives at fir a able cupric salt, but on prolonged treatment with the metal a cuprous salt is obtained. The cuprous salt and an excess of disulphide immediately give the cupric salt. Diethylthiocarbamic acid, containing only one sulphur atom, gives only a cuprous salt.
Synthese von Farbstoff‐Antipoden für Histologische Färbungen I
Authors: Kögl F. , Faber J. G. , de Boer Z. C. 
Published: September 2010

AbstractDie Frage, ob die Antipoden asymmetrisch gebauter Farbstoffe durch Wolle und Seide verschieden stark gebunden werden, ist bereits Gegenstand mehrerer Untersuchungen gewesen. In der vorliegenden Arbeit wurde die gleiche Fragestellung auf die histologische Färbung von tierischen Geweben übertragen. Zur Kernfärbung dienten spiegelbildliche Phenazin‐Derivate, die durch Kondensation von d‐ und l‐Campherchinon mit 2,3,6,7‐Tetraaminophenazin synthetisiert wurden. Die histologische Prüfung erfolgte bei normalen und bei malignen Geweben. Die durch d‐ und l‐Farbstoff hervorgerufenen Färbungen zeigten bei der visuellen Beobachtung praktisch keinen Unterschied in der Intensität.
The nature of the cessation reaction in free radical initiated additions of carbon tetrachloride to χ‐olefines: (Preliminary communication)
Authors: Kooyman E. C. 
Published: September 2010

AbstractEvidence is presented that the main chain‐breaking step in the free radical initiated addition of carbon tetrachloride to χ‐olefines consists in the reaction between a trichloromethyl radical and the χ‐methylenic group of the olefine, which leads to the formation of a molecule of chloroform and a stabilized allyl‐type radical which is incapable of continuing the chain.
Sur la présence de lédol dans une cistacée (cistus ladaniferus L)
Authors: Sabetay Sébastien , Gilly Pierre 
Published: September 2010

AbstractLes auteurs ont réussi à isoler à partir de l'essence de Ciste‐Labdanum de l'Estérel le lédol, alcool sesquiterpénique tricyclique tertiaire.
Dimerization of methylchavicol and of ethylchavicol with loss of hydrogen and ring formation. 1,2‐dianisylbenzene and 1,2‐diphenetylbenzene. A free radical as hydrogen acceptor?
Authors: van der Zanden J. M. , de Vries G. 
Published: September 2010

AbstractThe structure was determined of two products obtained respectively upon the polymerization of methylchavicol and of ethylchavicol. An attempt is made to give a plausible explanation of their formation.
The ethene‐water system
Authors: Diepen G. A. M. , Scheffer F. E. C. 
Published: September 2010

AbstractThe p‐t relations of the three‐phase equilibria in the system ethene‐water were determined from −15 to +20° C at pressures from 0 to 60 atmospheres. A dissociating compound, ethene hydrate, occurs, which is stable above the critical point of ethene and whose composition was determined by an indirect thermodynamic method and found to be C2H4.7 H2O.The system exhibits metastable immiscibility. The corresponding metastable three‐phase equilibrium was measured from 0 to 9.7° C.
The solubility of water in supercritical ethene
Authors: Diepen G. A. M. , Scheffer F. E. C. 
Published: September 2010

AbstractA method was worked out for determining the solubility of water in the fluid phase in the system ethene‐water, in which a solid compound, ethene‐hydrate, occurs. Several measurements were performed at 15.0 and 25.0° C. The solubility of water in the liquid phase was even found to attain twenty times the theoretical value.
L'action du diazométhane sur le bis‐méthylsulfonyl‐nitrométhane (les propriétés du groupe sulfonyle X)
Authors: Backer H. J. 
Published: September 2010

AbstractLe diazométhane réagissant sur le bis‐méthylsulfonyl‐nitrométhane donne naissance à un produit inflammable, qui manque des propriétés propres à un dérivé méthylé.L'auteur suppose que, sous l'influence des sulfonyles, le groupe nitro fixe le diazométhane, en conduisant, après la perte d'azote, à l'époxyde d'une imine. A froid déjà, le produit se dédouble en aldéhyde formique et bis‐méthylsulfonyl‐(iso) nitrosométhane.Le schéma, proposé pour la réaction du diazométhane, est appuyé par les résultats de celle du diazoéthane.Le composé (iso)nitroso, qui est peu stable en solution aqueuse, donne des dérivés incolores de méthyle et d'acétyle. Le composé est un acide, dont les sels sont colorés en jaune. L'auteur admet pour ces sels une structure nitroso, qu'il attribue à l'influence des groupes voisins de sulfonyle.
The stability of hydrocyanic acid at elevated temperatures
Authors: Sporzynski A. , Salter H. L. 
Published: September 2010

AbstractExplosions of hydrocyanic acid during storage are believed to result from the rapid uncontrolled polymerization of the acid, leading to a sudden increase in pressure of the gaseous concomitants.Cobalt oxalate or its admixture with nickel oxalate constitute outstanding stabilizers for hydrocyanic acid and are particularly effective in reducing risk of explosion (American and British patents have been claimed).Analysis indicates that their action is due to a liberation of oxalate ion into solution by hydrocyanolysis.The deterioration of hydrocyanic acid may be conveniently observed by a measurement of conductivity changes.Water is a main factor in deterioration, a proportion over 5% impairing to a very high degree the stability of hydrocyanic acid.An unprotected steel surface also exercises an adverse effect which may be eliminated by suitable (e.g. oxalate) coatings.
The action of atomic hydrogen on hexadecene‐1, hexadecane and linseed oil
Authors: Boelhouwer C. , Heertjes P. M. , Houtman J. P. W. , van Steenis J. , Waterman H. I. 
Published: September 2010

AbstractThe reaction of hydrogen atoms, prepared according to Langmuir by passing a stream of hydrogen over a glowing tungsten wire, with liquid hexadecene‐1, hexadecane and linseed oil is described.With hexadecane saturated higher molecular hydrocarbons are formed. With hexadecene hydrogenation as well as polymerization occurs, the polymerization products being partly unsaturated. With linseed oil conjugation of the double bonds occurs besides hydrogenation and polymerization, but only to a small extent.Interaction of H‐atoms with the double bond proceeds faster than with the saturated part of the molecule, though the last reaction definitely makes a contribution to the overall reaction. Formation of unsaturated products from the corresponding saturates hardly occurs.Other literature is reviewed in connection with the present work.
Décomposition Spontanée du Bis‐Méthylsulfonyl‐Isonitrosométhane: (Les propriétés du groupe sulfonyle XI))
Authors: Backer H. J. 
Published: September 2010

AbstractLe bis‐méthylsulfonyl‐isonitrosométhane est un produit peu stable qui, à la température ambiante, subit des décompositions compliquées. On a pu isoler ou démontrer sept produits de décomposition.Un de ces produits est la diméthyldisulfone, composé inconnu jusqu'ici et difficilement accessible. On explique sa naissance en admettant un doublement du radical méthylsulfonyle.Un produit plus compliqué, dont la formation accompagne celle de la disulfone, présente la formule empirique C4H10O5N2S2. On y peut attribuer la composition d'un dérivé d'oxadiazolidine (tétrahydrofurazane).
L'action de Diazométhane sur le Bis‐Méthylsulfonyl‐Isonitrosométhane: (Les propriétés du groupe sulfonyle XII )
Authors: Backer H. J. 
Published: September 2010

AbstractLe diazométhane réagit sur le bis‐méthylsulfonyl‐isonitrosométhane (III) de façon compliquée; on a pu isoler cinq produits à l'état pur. Les produits primaires sont l'éther méthylique (IV) et un isomère instable que nous considérons comme un dérivé d'éthylène‐hydroximine (V). Le chauffage de cet isomère donne naissance à la diméthyldisulfone.L'action prolongée du diazométhane sur l'éther méthylique (IV) conduit, par l'intermédiaire d'une triazoline peu stable (VI), à deux produits stables: un dérivé d'éthylène‐méthoximine (VII) et un triazole (IX). On peut diriger la décomposition de la triazoline (VI) de telle façon que l'on obtient exclusivement soit l'un soit l'autre des deux produits finaux (VII et IX).
The adsorption of carbon disulphide vapour flowing through a tube filled with activated charcoal
Authors: Vreedenberg H. A. 
Published: September 2010

AbstractThe course of the adsorption of carbon disulphide vapour from a mixture of air and CS2, which flows through a long tube with activated charcoal, is calculated as a function of the time and of the place in the tube. For this purpose the analogous theory on the increase of the temperature of a solid in a furnace, through which a hot liquid or gas flows, can be used. The results of the theory are recorded in fig. 2 to 4 inclusive, the meaning of which follows from the formulae (9), (14) and (15) (see further the elucidation in § 4). Some of the conclusions, which can be derived from them, are compared with the results of various experiments.
On the theory of ionic conductivity in crystals
Authors: Haven Y. 
Published: September 2010

AbstractA survey is given of the existing theories of the ionic conductivity in crystals.The experimental log x ‐ 1/T curves usually consist of two straight parts with different slopes. This shape can be explained by several mechanisms (Smekal, Jost and others). For the conductivity of mixed crystals, where the solute introduces additional vacancies, we derived a formula (formula III) which gives the conductivity as a function of the concentration of the solute and of the temperature. This formula also explains the kink in the conductivity curve.A method has been given which makes it possible to choose between the explanations for the kink in the conductivity curve in a given case. It is based on an analysis of the transition region between the two straight parts of the curves, and was applied to the conductivity of Li‐halides and LiHl‐MgHl2 mixed crystals. It was found that in this case the kink in the conductivity curves could be described by formula III and not by the mechanisms proposed by others.
Bromo‐derivatives of 3‐hydroxypyridine
Authors: Den Hertog H. J. , Schepman F. R. , de Bruyn J. , Thysse G. J. E. 
Published: September 2010

AbstractDescriptions are given of methods for the preparation of eight bromoderivatives of 3‐hydroxypyridine.2,4,6‐Tribromo‐3‐hydroxypyridine was obtained as reaction product in the bromination of 3‐hydroxypyridine in aqueous solution. When the bromination was carried out with the bimolecular quantity of bromine in pyridine as a solvent, 2,6‐dibromo‐3‐hydroxypyridine (m.p. 163°) could be isolated. We have not been able to confirm the observations of Fischer and Renouf who report the formation of a dibromo‐3‐hydroxypyridine (decomposition point: 200°) by the action of bromine water on 3‐hydroxypyridine.Finally some reactions of 2,4,6‐tribromo‐3‐hydroxypyridine are described.
Stabilisation of montmorillonite sols by chemical treatment. Part. II. Effect of polymetaphosphates, sodium metasilicate, oxalate, citrate and orthophosphate on Na and Ca montmorillonite sols
Authors: van Olphen H. 
Published: September 2010

AbstractThree different causes are concluded to contribute to the stabilisation of montmorillonite sols by polymeric phosphates, sodium metasilicate and sodium oxalate:
a charging effect due to adsorption of the anions to the edges of the micelle plates.
a decrease of the sodium ion activity in the mixture of stabilizer and flocculating salt.
an inactivation of strongly flocculating calcium ions by complex formation or precipitation.
The mechanism of the reaction between ozone and aromatic compounds. (Preliminary communication)
Authors: Wibaut J. P. , Sixma F. L. J. , Kampschmidt L. W. F. , Boer H. 
Published: September 2010

AbstractThe velocity of ozonisation of a number of aromatic compounds has been determined. Boron trifluoride and aluminium chloride exert an accelerating influence on ozonisation. On the basis of our experimental results it is probable, that the ozonisation of aromatic compounds takes place by an electrophilic reaction mechanism.
Rate of dissolution of solid substances. Part II (Chemical dissolution)
Authors: van Krevelen D. W. , Krekels J. T. C. 
Published: September 2010

AbstractThe rate of dissolution of benzoic acid granules in alcaline aqueous solutions has been studied. A formula of the kinetics of this chemical dissolution process has been derived. Mass transfer coefficients for film‐like flow of the dissolving agent can be correlated by the same dimensionless equation as in the physical dissolution process.
Synthesen auf dem Auxin‐Gebiet. III. Ein einfaches Strukturanalogon von Auxin‐a. 41. Mitteilung über pflanzliche Wachstumsstoffe
Authors: Kögl F. , Ultée A. J. 
Published: September 2010

AbstractDie vorliegende Arbeit behandelt eine Synthese, bei welcher an den Kern des Cyclopentens durch systematischen Aufbau die dem Auxin‐a zugeschriebene hydroxyl‐ und carboxyltragende Seitenkette angegliedert wurde. Der erhaltenen Säure bzw. ihrem δ‐Lacton fehlen die sekundären Butylgruppen des natürlichen Phytohormons. Hiermit dürfte die Unwirksamkeit im Avena‐test zusammenhängen, wie dies bei dem in der vorigen Mitteilung dieser Reihe beschriebenen, einfachen Analogon von Auxin‐b ebenfalls konstatiert wurde. Bei dem anscheinend einheitlichen Kristallisat handelt es sich um eines der vier theoretisch möglichen Racemate des Lactons. Während der leichte übergang in die freie Säure an das Verhalten von Auxin‐a‐lacton erinnert, scheint der Modellstoff durch Bestrahlung mit ultraviolettem Licht nicht verändert zu werden. Zur weiteren Klärung ist daher die Darstellung der stereoisomeren Verbindungen erforderlich.
A new method for the synthesis of furan derivatives: III ). Pyrolysis of δ‐sultones with two double bonds in the ring
Authors: Morel Th. , Verkade P. E. 
Published: September 2010

AbstractIn this paper directions are given for the preparation of furan derivatives by the pyrolysis of δ‐sultones with two double bonds in the ring. The examples relate to nine of the ten possible constitutional types.
Dissociation and tautomerism of some quinone monoximes
Authors: Havinga E. , Schors A. 
Published: September 2010

AbstractAn analysis by counter‐current distribution of the substance of m.p. ∼ 140° C, described as 3‐chloro‐nitrosophenol by Hodgson1) and described as 3‐chloro‐quinone monoxime by other authors4) 5) 2) gave support to the opinion already expressed 2) that this substance has a complex nature. The main component found in the solution of the substance was identical with 3‐chloro‐quinone monoxime (m.p. 182°).
Thermodynamic properties of mixtures of alkanes differing in chain length, III: The system hexane‐dodecane
Authors: van Der Waals J. H. 
Published: September 2010

AbstractHeats of mixing at 20° C are given for the system hexane‐dodecane. The results are in agreement with Brønsted's principle of congruence as derived from previous heat of mixing data on other binary alkane systems. The entropy of mixing in the present system is somewhat smaller than that following from Guggenheim's theory for athermal mixtures.
Amides VII. The use of diacylimines in the perkin reaction
Authors: Polya J. B. , Spotswood T. M. 
Published: September 2010

AbstractThe base catalysed reaction between diacylimines and aromatic aldehydes or furfural affords good yields of the expected unsaturated amides. E.g. 3‐(furyl‐2′)‐2‐methyl‐2‐propenoic amide, may be prepared by this method with a yield of 71%. Chloral and 3‐(furyl‐2′)‐2‐propenal give poor yields of the expected unsaturated amides but these yields are higher than those obtained through the normal Perkin reaction. Some aspects of the mechanism of the Perkin reaction are discussed in the light of new experimental evidence.
Titration of adsorbed acids IV
Authors: Tendeloo H. J. C. , Mans A. E. , de Hoogh G. 
Published: September 2010

AbstractThe titration curves of adsorbed isomeric acids are determined. The three hydroxy‐benzoic acids do not show any difference in the adsorbed state notwithstanding the isomerism and difference in acidity.The adsorption of the stereo‐isomerides fumaric and maleic acid results in the difference in acidity between the two acids being strongly reduced; the adsorption‐isotherms of the two isomerides show, that the adsorption of maleic acid is less than that of fumaric acid.We considered hitherto the adsorbed acids as polybasic acids, but it is also possible to take another point of view i.e. the theory of the Donnan‐equilibrium. The fact that the titration curves of adsorbed salicylic acid obtained with NaOH and with Ca(OH)2, do not coincide proves at least qualitatively that we have to do with the distribution of ions between the adsorbed phase and the solution according to the Donnan‐equilibrium.By increasing the amount of adsorbent, primarily the adsorbed acid becomes gradually more weak, thereafter the acidity of the acid appears to increase again.
Oxydation des tétrathioorthocarbonates aromatiques: (Propriétés du groupe sulfonyle XVI)
Authors: Backer H. J. 
Published: September 2010

AbstractL'oxydation ménagée des tétrathioorthocarbonates de phényle et de p‐tolyle, en solution rigoureusement anhydre, conduit aux diaryldisulfones correspondantes. On peut caractériser ces disulfones en les décomposant au moyen de pipéridine; cette scission donne le benzène (toluéne)sulfo‐pipéridide et le benzène(toluène)sulfonate de pipéridine.Apparemment ni les esters aliphatiques, ni les esters aromatiques de l'acide tétrathioorthocarbonique ne donnent finalement des tétrasulfones. La cause de ce fait peut être la surcharge à laquelle l'atome central serait exposé de la part des quatres groupes égaux, avides d'électrons.
Kinetic analysis of organic halides. Part III. Analysis of low molecular polyhalides
Authors: Salomon G. , Ultée A. J. 
Published: September 2010

AbstractThe reactions of polychlorinated ethanes and propanes, with aniline and piperidine, have been studied and the results are compared with data obtained previously for monohalides.Vicinal polychlorides are stable towards aniline at 100° C, but reactive with piperidine at 100° C. Certain polychlorides with >CCl2 or ‐CCl3., groups are distinguished from the former by their ease of reaction with piperidine at room temperature.Mixtures of monochlorides and polychlorides can be subjected to kinetic analysis by a combination of these tests. It is possible to recognise different groups, but a quantitative kinetic separation of the fractions can not always be achieved.Application of this method to chlorinated paraffins with 42 % Cl and 70 % Cl reveals that the distribution of chlorine in these molecules is not at random. The reactivity of these chlorinated paraffins indicates the occurrence of > CCl2 groups.