bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetic analysis of organic halides. Part. IV. Analysis of macromolecular polyhalides
Authors: Salomon G. , Koningsberger C. 
Published: September 2010

AbstractChlorination products derived from natural rubber and some synthetic polymers have been subjected to kinetic analysis with aniline at 100° C and piperidine at 20° C. The influence of the chlorinating agent on the structure of the reaction products has been elucidated.It is shown that allylic chloride groups, the rubber dichloridemagnified imageand rubber polychlorides can be identified and separated kinetically.By a combination of kinetic and infrared analysis the structuremagnified imagecan be proved as the primary reaction product of direct chlorination.
The directive influence of the N‐oxide group during the nitration of derivatives of pyridine‐N‐oxide
Authors: den Hertog H. J. , Kolder C. R. , Combé W. P. 
Published: September 2010

AbstractThe nitration of some mono‐substituted derivatives of pyridine‐N‐oxide containing a bromine atom, an ethoxy‐ or a methyl‐group in positions 2 or 3, has been investigated.When these compounds are heated With a mixture of fuming nitric acid and sulphuric acid, a nitro‐group is introduced into the 4‐position. It appears that the course of the nitration is not influenced by the presence of the bromine atom, the ethoxy‐ or methyl‐group in the nucleus. A 4‐nitro‐compound is obtained even from 2‐ethoxypyridine‐N‐oxide, the nitro‐group entering the meta‐position with respect to the strongly ortho‐para directing ethoxy‐group.
Polymerisation of methylchavicol: Dimerisation coupled with hydration
Authors: van der Zanden J. M. , de Vries G. 
Published: September 2010

AbstractThe action of 43 % sulphuric acid on methylchavicol

has afforded metanethole, m.p. 135°, along with a mixture of substances, which can be shown to contain in all probability isoanethole and from which two products melting at 76.5° and 94°, respectively, could be isolated. The structures of these two products has been determined.
The U.V. absorption spectra of p. Amino‐salicylic acid and some related compounds (I)
Authors: v. d. Stelt C. , Rekker R. F. , Nauta W. Th. 
Published: September 2010

AbstractThe U.V. absorption spectra of p.amino‐salicylic acid were measured both in water and in ethanol. The results of these measurements show that there is no discrepancy between the work ofWaya.o. andDraina.o. as was suggested by the latter authors.In addition the U.V. absorption spectra of some related compounds were measured.
1,1‐Dichlorodienes‐1,3: I. Preparation of 1,1‐dichlorobutadiene and of 1,1‐dichloro‐n‐hexadiene
Authors: Kooyman E. C. 
Published: September 2010

AbstractPyrolysis of 1,1,1,3‐tetrachlorobutane at 450‐460° C gives 1,1‐dichlorobutadiene‐1,3; from 1,1,1,3‐tetrachlorohexane 1,1‐dichlorohexadiene‐1,3 was obtained.These new dienes have an ultra‐violet absorption maximum at 2430 and 2465 Å, respectively. They polymerize to viscous oils on standing, but do not react with maleic anhydride or sulphur dioxide.
On the quantitative analysis of gas mixtures, which contain nitrogen as well as the various oxides of nitrogen
Authors: Meyer G. , Voogel P. 
Published: September 2010

AbstractA method has been worked out to determine nitrogen in the presence of the various oxides of nitrogen by the processes of gas analysis. According to this method, the gas is divided into three fractions, which consist respectively of nitrogen, nitrogen peroxide and a mixture of nitrous oxide and nitric oxide, after which the two latter fractions are analysed. The volumetric determination of gases, which contain nitrogen peroxide, is not required for this analysis.We believe that the accuracy of the method described by us is certainly not worse than that of the customary titrimetric methods of determination.
O‐hetero‐analogues of steroids
Authors: Bolt C. C. 
Published: September 2010

AbstractSeveral 1,2‐cyclopentano‐2,5‐dimethyldecalone‐6‐propionic acid‐5 derivatives have been prepared by ozonization of ▵4‐3‐ketosteroids, followed by reduction with sodium and ethanol, yielding hydroxycarboxylic acids. In neutral or acid solution ring closure occurs to the lactones. The resulting 4‐oxa‐3‐ketosteroids probably have the cholestane configuration. This group of substances crystallize readily from the usual organic solvents.
Investigations on organic fungicides: V. Chemical constitution and fungistatic activity of aliphatic bisdithiocarbamates and isothiocyanates
Authors: Klöpping H. L. , van der Kerk G. J. M. 
Published: September 2010

AbstractIn this paper, the investigations on the relations of structure to antifungal activity of sulphur compounds described in the previous publication of this series are extended to bisdithiocarbamates and isothiocyanates. The most active sulphur fungicide described in the literature so far, disodium ethylenebisdithiocarbamate, is surpassed by a new fungicide mentioned below, viz. ethylene diisothiocyanate. It is suggested that the antifungal action of bisdithiocarbamates is primarily attributable to the formation in situ of the corresponding diisothiocyanates.
On the reactions of the lithium compound of 2,6‐dimethylpyridine with benzyl chloride, benzoic anhydride or benzonitrile
Authors: de Jong J. I. , Wibaut J. P. 
Published: September 2010

AbstractWhen 2 mol. of phenyllithium are allowed to react with 1 mol. of lutidine and the mixture is then treated with an excess of benzyl chloride, α‐methyl‐α′‐(dibenzyl‐methyl) pyridine (I) is produced along with α‐methyl‐α′‐phenylethylpyridine (VI). The statement of Bergmann and Rosenthal, that α,α′‐bis‐(phenylethyl)pyridine (II) should be produced in this reaction, is incorrect.When 2 mols. of phenyllithium are allowed to react with 1 mol, of lutidine and the product is treated with an exces of benzoic anhydride, a derivative of lutidine is produced, which, contrary to the opinion of Kloppenburg and Wibaut, is to be considered as the benzoate of the enol form of 2‐phenacyl‐6‐methylpyridine (VIIb).(VIII). By the interaction of 2 mols. of phenyllithium and 2 mols. ofThe action of 1 mol. of phenyllithium and 1 mol. of benzonitrile on 1 mol. of α,α′‐lutidine leads to the formation of 6‐methyl‐2‐phenacylpyridine (VIII). By the interaction of 2 mols of phenyllithium and 2 mols of benzonitrile on 1 mol. of α,α′‐lutidine, a complicated reaction takes place with the formation of a compound C21H19N3, to which a tricyclic structure (XI) is ascribed.
Kinetical experiments on ozonisation reactions: I. Apparatus
Authors: Boer H. , Sixma F. L. J. 
Published: September 2010

AbstractA description is given of the apparatus used for the kinetic measurements on ozonisation reactions described in part II1).A constant stream of a mixture of ozone and oxygen of variable but constant (within 3‰) composition is electrolytically generated by a stabilized generating device.A thermostat suitable for temperatures between 0° and −70° C, varying within 0.04° C, is described.The solubility of ozone in chloroform has been determined.
Preparative chromatographic separation of glycine, sarcosine and dimethylglycine using starch
Authors: Sluyterman L. A. Æ. , Veenendaal H. J. 
Published: September 2010

AbstractGlycine, methylglycine (sarcosine) and dimethylglycine can be quantitatively separated in starch columns using water‐alcohol 2:1 (v/v) as eluting agent. If amino acid hydrochlorides are to be separated, the eluting agent must be acidified with HCl.Likewise the partial separation of some peptides has been achieved by applying water‐alcohol 2:1.
Etude Spectrographique et Thermogravi‐Metrique de Quelques Antimoniates
Authors: Dupuis Thérèse 
Published: September 2010

AbstractCette étude porte sur les antimoniates de potassium, sodium, baryum, argent et plomb, considérés à l'état solide, à froid, et après déshydratation par chauffage. Pour chacun d'eux, on a enregistré le spectre d'absorption infrarouge, entre 600 et 2000 cm−1 et la courbe de thermolyse, entre 20° et 1000° C, afin, 1° de vérifier la formule de Pauling pour les produits non chauffés, 2° de connaitre la structure des corps qui en dérivent par chauffage.
Etude des Produits de Condensation du Benzaldehyde Avec la Methylamylcetone et la Methylisobutylcetone
Authors: Metayer Maurice 
Published: September 2010

AbstractL'auteur étudie la condensation du benzaldéhyde sur la méthylisobutylcétone et la méthylamylcétone. Les propriétés chimiques des styryl‐alkyls cétones obtenues sont investies.
Reaction products of primary β‐hydroxy‐amines with carbonyl compounds. II. Molecular refraction and infrared spectrum
Authors: Bergmann Ernst D. , Zimkin E. , Pinchas S. 
Published: September 2010

Abstract
The condensation of a number of carbonyl compounds with ethanolamine and with amino‐alcohols having a tertiary hydroxy‐ and a primary amino‐group, has been studied. The molecular refraction and the infrared spectrum have been used to distinguish between the oxazolidine and Schiff's base structures which are both possible for the condensation products.
Aromatic and α,β‐unsaturated carbonyl compounds, on the whole, tend to form Schiff's bases, saturated carbonyl compounds oxazolidines, with ethanolamine. Introduction of C‐alkyl groups into the ethanolamine system favours the formation of oxazolidines even with aromatic aldehydes and ketones.
In the infrared spectrum of simple CN‐compounds in alcoholic solution, a solvation effect has been observed. Also, the tautomerisability of substances containing the system CH−1—CN, to HC  C—NH has been demonstrated.
The (non‐conjugated) CN double bond absorbs in the infrared at about 1670 cm−21 whilst the oxazolidine system is characterised by three bands (1149—1185; 1116—1139; 1086—1118 cm−1) in the 1100—1200 cm−1 region.
The similarity of the infrared spectra of all heterocyclic substances of the general type magnified image is stressed.
Reaction products of primary β‐hydroxy‐amines with carbonyl compounds. IV. Infrared and ultraviolet absorption spectra of ethylenediamine derivatives
Authors: Bergmann Ernst D. , Meeron E. , Hirshberg Y. , Pinchas S. 
Published: September 2010

Abstract
Eight ketones and p‐chlorobenzaldehyde have been condensed with ethylenediamine. Only cyclohexanone and its methyl‐derivatives give imidazolidines; in all other cases, double Schiff's bases are formed. The assignment of structures is based on the infrared spectrum.
The infrared spectra of two hexahydropyrimidine derivatives have been studied for the sake of comparison.
The ultraviolet spectra of the double Schiff's bases have been measured.
The similarity in the infrared spectrum of 1,3‐dioxolanes, oxazolidines, imidazolidines and thioxolanes is stressed. Two representatives of the last class of compounds have been prepared and their physical properties studied.
Reaction products of primary β‐hydroxy‐amines with carbonyl compounds. VII. Oxazolidines derived from N‐methylethanolamine
Authors: Bergmann Ernst D. , Zimkin E. , Pinchas S. 
Published: September 2010

AbstractThe preparation of ten N‐methyloxazolidines, their molecular refraction and infrared absorption spectrum are reported. The molecular refractions show a depression which is ascribed to the oxazolidine ring. The infrared absorption spectra consist of a number of bands in the 1050–1190 cm−1 region, characteristic of the magnified image group and the tertiary nitrogen.
Reaction products of primary β‐hydroxy‐amines with carbonyl compounds: VIII. Variation thermique de la réfraction moléculaire
Authors: Metzger Jacques 
Published: September 2010

AbstractDeux problèmes de tautomérie posés par l'étude expérimentale de certains dérivés de condensation de β‐hydroxyamines primaires avec des composés carbonylés sont envisagés à la lumière de la technique réfractométrique. L'étude de la Réfraction Moléculaire (R.M.) à 20° permet de confirmer l'hypothèse de cette tautomérie. La variation thermique de cette R.M. ajoute un argument supplémentaire et permet de prévoir le sens de l'évolution de la tautomérie en fonction de la température. Un mécanisme raisonnable est proposé pour expliquer cette transformation tautomère.
Thermal quantities of some cycloparaffins. Part III. results of measurements
Authors: Kaarsemaker Sj. , Coops J. 
Published: September 2010

AbstractThe heats of combustion, melting points, heats of fusion, boiling points, refractive indices and in four cases the densities have been determined on selected samples of the cyclanes with 4 to 9 C‐atoms; some hitherto unknown transition points were discovered and the heats of transition measured. The heats of vaporisation at 25° are estimated. Results of the measurements are discussed.
Reductive alkylation of 2‐aminopyridine and 2‐aminopyrimidine
Authors: Kaye Irving Allan , Kogon Irving C. 
Published: September 2010

AbstractN‐Monosubstituted 2‐aminopyridines are formed in high yield when the corresponding Schiff bases are refluxed in formic acid‐cumene solution. For the preparation of N‐monosubstituted 2‐aminopyrimidines, refluxing 2‐aminopyrimidine and an aldehyde in formic acid seems preferable. The products are readily purified, and yields are increased by vacuum distillation followed by recrystallization. A procedure which is satisfactory for the preparation of 2‐aralkylideneaminopyridines gives N,N′‐benzilidene‐bis‐2‐aminopyrimidine from benzaldehyde and 2‐aminopyrimidine.
Hydrolyse et Aminolyse DBS 1,1,1,1‐Disulfure‐Disulfones. (Propriétés du groupe sulfonyle XXVI)
Authors: Backer H. J. 
Published: September 2010

AbstractAprès l'étude de l'hydrolyse de (CH3S)2C(SO2CH3)22) on a examiné les dérivés portant un ou plusieurs groupes phényle au lieu de méthyle.L'hydrolyse acide de ces composés conduit à des esters de l'acide dithiocarbonique; outre des esters connus on a obtenu ainsi le di‐ester mixte de méthyle et de phényle.L'hydrolyse basique expulse un groupe méthylthio ou phénylthio. qui est reraplacé par l'hydrogène. Lorsque les deux fonctions thioéther ne sont pas égales, l'hydrolyse s'accomplit en deux directions.La pipéridinolyse réussit dans la plupart des cas aisément avec dégagement de chaleur. Pour les composés à deux fonctions thioéther différentes, la préférence entre les deux groupes diffère de celle observée pour l'hydrolyse alcaline.
The use of glass electrodes for the measurement of activities of metal ions
Authors: van Schuylenborgh J. , Vervelde G. J. 
Published: September 2010

AbstractGlass electrodes of the “mixed electrode” type can be used with advantage to measure activities of metal ions in systems of known pH, containing only one kind of metal ions. The use of a valve electrometer adapted to very high input resistances made it possible to use robust bulb electrodes of a high chemical and electrical resistance. These electrodes appeared to be very suitable for this purpose and produced remarkably reproducible figures.The relationship between the potentials measured and the ion concentrations was examined theoretically and found to be in agreement with the assumption, that glass behaves as a weak acid and that the potentials are essentially membrane potentials in a Donnan system.
Arenicochrome, a new pigment from arenicola marina L: Isolation and composition
Authors: van Duijn P. 
Published: September 2010

AbstractArenicochrome, a green granular pigment in the epithelial cells of Arenicola marina L., first described histologically and histochemically by Lignac, was extracted from the worm by means of ammoniacal alcohol containing cyanide. After chromatography on aluminium oxide, crystallization of the pigment as a potassium salt was achieved. The formula of this salt proved to be (C21 H15 S2 O14 K3)n where n = 1 or n = 2. Of the three salt‐forming groups (minimum formula) one has a pK of 5.7; the dissociation of this group is accompanied by a colour‐shift from orange to blue. The two remaining groups are of a strong acid character. The absorption spectra of the compound at different pH values are reported. Some biological problems resulting from the investigation are briefly discussed. In addition some other properties of he pigment are mentioned.
The adsorption of nitrogen, hydrogen and their mixtures on silica gel
Authors: van der Waarden M. , Scheffer F. E. C. 
Published: September 2010

AbstractAdsorption isotherms of hydrogen and nitrogen on silica gel were determined up to equilibrium pressures of approx. 800 mm mercury and at temperatures between +300 and —195°C. The adsorption of nitrogen‐hydrogen mitxures at a total equilibrium pressure of 760 mm mercury was determined at 0, —78 and —183°C.At 0 and —78°C the adsorption of hydrogen is increased by the presence of nitrogen and the adsorption of nitrogen is reduced by the presence of hydrogen; at —183°C the adsorption of hydrogen is strongly reduced by the presence of nitrogen and the adsorption of nitrogen is hardly affected by the presence of hydrogen.The adsorption at temperatures above the critical temperature of the individual gases, as well as that of their mixtures is qualitatively in agreement with the conception that the adsorbed phase is a gas phase condensed under the influence of the adsorbent.
The redox potential as a critical factor in the hill reaction
Authors: Wessels J. S. C. , Havinga E. 
Published: September 2010

AbstractThe photochemical reduction of various quinones and dyes by water in the presence of chloroplasts was studied by measurement of the redox potential during illumination. Whether this Hill reaction will proceed to a measurable degree appears to be determined by the standard potential of the redox substance. With systems having a standard potential of about 40 millivoltsRedox potentials in this paper are given with reference to the normal hydrogen electrode at pH = 6.5, and if possible at a temperature of 16° C.
or lower, no reduction was observed.
The properties of a number of cyclic olefins
Authors: van der Bij J. R. , Kooyman E. C. 
Published: September 2010

AbstractA number of cyclic olefins having six, seven or eight carbon atoms were prepared and some of their properties investigated.The olefins were synthesized by pyrolysis of acetates; olefin contents were determined by means of the ozone addition method. Purities were investigated by ozonolyses, separating and isolating the carbonyl compounds formed by chromatography of the 2,4‐dinitrophenylhydrazones.
The quantum yield of the photo‐decomposition of some aromatic diazonium salts
Authors: de Jonge J. , Dijkstra R. , Wiggerink G. L. 
Published: September 2010

AbstractThe quantum yield of the photo‐decomposition of some aromatic diazonium salts in solution is estimated, using light with a wavelength of 3650 Å.The photo‐decomposition of phenyl‐amino benzene diazonium sulphate is proposed as a suitable actinometer.The quantum yield of the photochemical isomerisation of stable p‐methoxy‐benzenediazo‐cyanide was found to be about 0.35.
The dehydrogenation of hydrocarbons by means of quinones. II. Kinetics of the reaction with chloranil; dehydrogenations with other quinones
Authors: Dost N. 
Published: September 2010

AbstractThe dehydrogenation of hydrocarbons by means of tetrachloro‐p‐benzo‐quinone (chloranil) was found to proceed according to the overall equation: hydrocarbon + quinone → dehydrogenated hydrocarbon + hydroquinone. The kinetic order of the reaction proved to be bimolecular. The rate of reaction depended on the concentration of hydrocarbon and of quinone.A correlation was found to exist between the oxidation‐reduction potentials of a number of substituted quinones and their activity in the dehydrogenation of tetralin to naphthalene.
A investigations in the vitamin A‐series. II. Allylic rearrangements in the vitamin A‐series
Authors: Huisman H. O. , Smit A. , Vromen S. , Fisscher L. G. M. 
Published: September 2010

AbstractBy splitting off water from the intermediate hydroxy‐compounds in the Vitamin A‐series allylic rearrangement takes place into the cyclohexene ring. This rearrangement occurs throughout the whole Vitamin‐A‐series‐ with those hydroxy‐intermediates wherein the hydroxy‐group is in an allyl position with regard to the double bond in the cyclohexene ring.The reason why so many attempts to prepare synthetic Vitamin A in reasonable yields, starting with “key” intermediates other than the C14aldehyde, lead to a failure, has been outlined.
Trityl derivatives of amines: I. N‐trityl derivatives of aromatic primary amines
Authors: Verkade P. E. , Nijon H. , Tollenaar F. D. , van Rij J. H. , van Leeuwen M. 
Published: September 2010

AbstractThe reaction of aromatic primary amines with trityl chloride at room temperature and in the presence of an excess of pyridine as a rule leads to N‐trityl derivatives.
Sur L'activité Optique D'échantillons de Mimosine (Leucaenol) de Provenance Différente
Authors: Wibaut J. P. , Schuhmacher J. P. 
Published: September 2010

AbstractUn échantillon de leucaenol qui a été isolé, dans le temps, par Mascré des graines de Leucaena glauca B, provenant de Cochinchine, et que cet auteur décrit comme optiquement inactif est, d'après nos observations, lévogyre: [α]D22=−20°. Cet échantillon est identique ä un échantillon de mimosine (leucaenol) que nous avons isolé des graines de Leucaena glauca B provenant de Java.
Quelques Thiolsulfonates de Trichloro‐Méthyle. (Propriétés du groupe sulfonyle XXVIII )
Authors: Backer H. J. , Westerhuis E. 
Published: September 2010

AbstractLe chlorure trichlorométhanesulfénique CCl3SCl réagit aisément sur les sulfinates de sodium en donnant naissance à des thiolsulfonates de trichlorométhyle: RSO2SCCl3. Plusieurs composés décrits dans nos trois mémoires présentent des propriétés fungicides.
Free‐radical reactions involving sulphur compounds. I. The interaction of 2‐cyano‐2‐propyl radicals and thiols
Authors: Bruin P. , Bickel A. F. , Kooyman E. C. 
Published: September 2010

AbstractThe reaction of thiols (R'SH) with 2‐cyano‐2‐propyl radicals (R), generated by thermal decomposition of 2,2′‐azoisobutyronitrile (RN = NR), was investigated.The radicals (R) readily abstract a hydrogen atom from the thiol (R'SH), producing isobutyronitrile (RH) and thiyl radicals (R'S), whilst their dimerisation product, tetramethylsuccinonitrile (RR), is also formed in appreciable quantities. Using primary, secondary and tertiary thiols respectively, decreasing yields of isobutyronitrile (RH) and increasing yields of tetramethylsuccinonitrile (RR) were obtained. This indicates that the reactivity of thiols towards R decreases in the same order. There appeared to be little difference between toluene‐α‐thiol and n‐octane‐1‐thiol.The thiyl radicals (R'S) combine to form disulphide (R'SSR') and with 2‐cyano‐2‐propyl radicals (R), to form mixed sulphides (R'SR). The latter are formed in far lower yields than both the disulphides and tetramethylsuccinonitrile. This phenomenon may be related to the fact that the CS bond is weaker than could be expected from the energies of the CC and SS bonds.
On the use of matrix‐like arrays as chemical symbols
Authors: Zernike J. 
Published: September 2010

AbstractThe isomorphous replacement of two elements simultaneously by two others is symbolized by a square matrix. Again three such matrices, representing the cyclic replacement of two elements out of three by two others, may be contracted into one matrix of three columns and two rows. In all these the coordinative binding of aluminium is indicated by its place.These symbols may be combined with one another, or with existing symbols concerning the isomorphous replacement of one element by one other. Thus a clear survey of silicate chemistry is obtained.By placing appropriate coefficients above the columns of the matrix, a particular mixed crystal may be represented. On the strength of this, an opinion is advanced as to the most probable composition of sarcolite.
Dérivés 9‐Méthylthio et 9‐Méthylsulfonyle du Thioxanthène‐10‐Dioxyde et leur Hydrolyse: Propriétés du groupe sulfonyle XXX
Authors: Kloosterziel H. , van der Veen W. , Backer H. J. 
Published: September 2010

AbstractAyant complété la série des thioxanthène‐10‐dioxydes, substitués en position 9 par des groupes méthylthio et méthylsulfonyle, les auteurs ont étudié l'hydrolyse acide et basique de ces composés, qui peuvent être envisagés comme des vinylogues de 1,1‐disulfones substituées.