bluuebunny/crossref_metadata_2025_split huggingface dataset:
The decomposition of some alkyl acetates
Authors: Houtman J. P. W. , van Steenis J. , Heertjes P. M. 
Published: September 2010

AbstractThe decomposition at high temperatures over glass‐wool of the acetic acid esters of butanol‐1, butanol‐2, 2‐methylpropanol‐1, 2‐methylpropanol‐2, 2‐methylbutanol‐1, 3‐methylbutanol‐1 and hexadecanol‐1 to acetic acid and the corresponding alkene was investigated. It was found that glass‐wool is not the active catalyst for the reaction. In some cases a small amount of isomerism of the double bond could be detected. Some observations on the reaction mechanism are included.
The insecticidal constituents of pachyrrhizus erosus urban. I
Authors: Meijer Th. M. 
Published: September 2010

AbstractA review of the literature concerning investigations, chemical as well as insecticidal of the seeds of Pachyrrhizus erosus Urban is given. The fatty‐oil content and the content of material that may be extracted with ether have been determined for a number of samples and recorded in a table. The oil extract varied from 20.0–22.9 per cent, the ether extract from 1.0–2.0 per cent. The latter has been found to be very toxic for caterpillars of the cabbage butterfly. Chemical investigation of the ether extract led to the isolation of several substances, one of which, called pachyrrhizone, had the composition C21H16O7, with a melting point of 248° C and a specific optical rotation in chloroform of − 95°. An oxime was prepared, with a melting point of 269–272°C. One OCH3 group was present. A dehydro compound C21H16O7 was formed by treatment with iodine and sodium acetate, ring‐fission probably taking place. A compound called pachyrrhizonic acid C21H16O11 was obtained by the action of alcoholic potash, a tentative formula for this derivative is given. On oxidation with potassium permanganate a substance C9H10O5, melting point 183–184° C. was formed, to which the constitution of 2‐methoxyhydroquinone‐4‐hydroxy acetic acid was given. The investigation is to be continued.
Untersuchungen über Indolderivate VIII. Einige vorläufige Versuche über den Einfluss des (Pseudo‐)‐Katalysators bei der Bildung von Indolderivaten aus Phenylalkylamino‐propanonen
Authors: Verkade P. E. , Lieste J. , Meerburg Frl. W. 
Published: September 2010

AbstractFestgestellt wurde, dass die Bildung von Indolderivaten aus Phenylalkylaminopropanonen unter Einfluss von Zinkchlorid und von Salzsäure auf typisch verschiedene Weise verläuft. Letztere Substanz hat eine viel stärkere spaltende Wirkung auf das α‐Arylaminoketon als erstere und lässt dadurch die Bildung von Indolderivaten unter Umlagerung mehr oder weniger in den Vordergrund treten. Mit Zinkchlorid als (Pseudo‐)Katalysator tritt praktisch nur wahre Ringschliessung auf. Der Unterschied zwischen der Wirkungsweise beider (Pseudo‐)Katalysatoren liess sich für präparative Zwecke verwenden.
Δ5,6‐acetoxy‐3 β‐hydroxy‐17‐nor‐cholenic acid lactone, a by‐product of the cholesterol oxidation
Authors: Veer W. L. C. , Goldschmidt St. 
Published: September 2010

AbstractThe isolation of the semicarbazone C47H69O7N3, from a semicarbazone fraction of the cholesterol oxidation is described. This semicarbazone is a double compound between trans‐dehydroandrosterone acetate semicarbazone and a lactone C25H36O4, previously described by Miescher and Fischer. The structure of this lactone was examined and proved to be Δ5,6‐acetoxy‐3 β‐hydroxy‐17‐nor‐cholenic acid lactone.
Investigations on sterols: I. A new synthesis of 7‐dehydrocholesterol (provitamin D)
Authors: Buisman J. A. Keverling , Stevens W. , Vliet J. V. D. 
Published: September 2010

AbstractA new synthesis of 7‐dehydrocholesterol (provitamin D3) from cholesterol is described, which gives a higher yield than the well known Windaus synthesis. The synthesis is carried out via a 7‐bromocholesteryl ester, from which hydrogen bromide is eliminated to give an ester of 7‐dehydrocholesterol.Careful hydrolysis of the impure 7‐bromocholesteryl benzoate affords either 7‐α‐ or 7‐β‐hydroxycholesteryl‐3 benzoate depending on the reagent. The two epimeric 7‐bromocholesteryl benzoates are prepared from the hydroxy‐compounds by interaction with phosphorus tribromide; the two hydroxy‐compounds are regenerated by hydrolysis.
Note on the theory of ionic association
Authors: Broer L. J. F. 
Published: September 2010

AbstractThe derivation of the Fuoss distribution function for ion pairs in a strong electrolyte is discussed. An improvement of this function is proposed which is adapted to the calculation of the number of associated pairs. In a simple case the association is computed with the corrected and uncorrected functions and compared with the exact value obtained from the law of mass action.
Researches on heat of combustion V: Correction for heat exchange between calorimeter vessel and its surroundings
Authors: Coops J. , van Nes K. 
Published: September 2010

AbstractIn order to be able to calculate readily the so‐called “radiation” correction in calorimetric measurements, the jacket‐temperature must be kept constant and the contents of the calorimeter vessel must be stirred at a constant speed. This article describes a thermo‐regulator for this purpose, in which the fluctuations are not greater than 0.002°.For every calorimeter used for accurate work, it is desirable to investigate beforehand whether the heat exchange between the vessel and the jacket satisfies Newton's equation. With the help of recent data it has been investigated how wide the air layer may be before convection occurs. This is necessary in order to obtain a system which satisfies Newton's equation.Finally, various methods of approximation for calculating the “radiation” integral are discussed.
The ozonization of naphthalene and its homologues: (Remarks on a paper by J. P. Wibaut and J. van Dijk, “The ozonization of 2,3‐dimethylnaphthalene” etc.)
Authors: Kooyman E. C. 
Published: September 2010

AbstractSome amplifying remarks are made on the paper by Wibaut and van Dijk concerning the ozonization of 2,3‐dimethylnaphthalene and 1,4‐dimethylnaphthalene.It is shown that the experimental results may be interpreted in accordance with former conclusions regarding the bond structure of the naphthalene molecule, viz. that a double bond seems to be available at the α,β‐positions only.
Discussion of the structure of a few polychloro compounds with the help of raman effect data
Authors: Gerding H. , Rijnders G. W. A. 
Published: September 2010

AbstractSome remarks are made concerning the structures of a heptachlorobutane and two pentachlorobutanes prepared by Prins and of a dodekachlorohexane of van der Linden.The structures of two fractions obtained by distilling a mixture of cis‐ and trans‐tetrachloropropene‐1 are discussed with the help of Raman effect data and dielectric measurement results given in this paper. No definite conclusion could be drawn, although in particular the Raman results make it probable, that the higher boiling fraction agrees with the cis isomer. Isomers due to hindered rotation about the CC single bond are present for this isomer also.The open chain compound C5Cl8 has the formula CCl2 = CCl. CCl = = CCl. CCl3 as was already made probable by Prins. Taking account of hindered rotation around the single bond, and stereoisomerism caused by one of the double bonds, a trans‐trans configuration seems by far the more probable one on steric grounds.Liquid decachlorohexadiene C6Cl10 possesses ‐ according to the Raman data ‐ the structure CCl3. CCl = CCl. CCl = CCl. CCl3. The presence of two conjugated double bonds in this molecule is highly probable. The conversion of solid C6Cl10 ‐ CCl2=CCl. CCl2. CCl2. CCl = CCl2 according to Prins ‐ into liquid C6Cl10 would therefore be coupled with the displacement of two double bonds.
Researches on sulphanilamide, para‐amino‐benzoic acid and their derivatives. III: Ultraviolet absorption spectra and potentiometric titrations
Authors: Havinga E. , Veldstra H. 
Published: September 2010

AbstractWith the aim of providing more facts for the discussion of the mode of action of the sulphonamides and of p‐aminobenzoic acid, the ultraviolet absorption spectra are recorded for a number of sulphanilamide derivatives, p‐aminobenzoic acid and related compounds.Moreover their electrochemical properties are determined by potentiometric titration.The results obtained permit a more detailed discussion of the state of these molecules in neutral solution, of the differences between p‐aminobenzoic acid and its isomers and of those between sulphanilamide and its heterocyclic derivatives.Furthermore the separate position of compounds like p‐aminomethylbenzoic acid and of p‐aminomethyl‐benzenesulphonamide (Marfanil) is clearly indicated.
The isomerization equilibria of the butanes, pentanes, hexanes and heptanes
Authors: van Eijk van Voorthuijsen J. J. B. 
Published: September 2010

AbstractIn continuation of the experiments described in a publication by Schuit and co‐workers we determined, partly re‐determined, the equilibrium positions of the isomerization reactions of the paraffin hydrocarbons of 4 to 7 carbon atoms.In spite of the use of a very active AlCl3 catalyst the following hydrocarbons were not formed under the conditions applied:C5: dimethylpropane (neopentane); C7: 2,2‐dimethylpentane (neoheptane); 3,3‐dimethylpentane and 3‐ethylpentane.Conversely, neoheptane (the only one of those four hydrocarbons that was available) remained completely unattacked under the same conditions.The results of our measurements were compared with experimental and thermodynamically calculated data from the literature. In the case of the butanes, pentanes and hexanes the agreement with the thermodynamic equilibrium position was moderate to good, in the case of the heptanes rather considerable deviations were found.
Dérivés des Nitrophénylsulfonyl‐Guanidines
Authors: Backer H. J. , Moed H. D. 
Published: September 2010

AbstractLa réaction des nitrobenzènesulfochlorures sur la guanidine engendre les mono‐nitrophénylsulfonyl‐guanidines. Comme produits secondaires, on obtient les bis‐nitrophénylsulfonyl‐guanidines, qu'on peut préparer également en introduisant un second groupe nitrophénylsulfonyle dans les composésmono. Ce dernier procédé offre la possibilité d'obtenir les composés‐bis mixtes, ayant deux groupes nitro en position différente. Les composés‐bis étant solubles dans les alcalis, les deux groupes nitrophénylsulfonyle doivent être liés à deux atomes d'azote différents.Lorsqu'on fait agir les nitrobenzènesulfochlorures sur la diméthylguanidine asym. et sur la tétraméthylguanidine sym., on n'obtient que les produits mono‐nitrophénylsulfonyle; il n'y entre pas un second groupe substituant.La réaction des nitrophénylsulfochlorures sur la p‐nitrophénylguanidine et sur la diphénylguanidine sym. donne naissance à plusieurs produits.
The calculation of maxima in vapour‐pressure curves
Authors: Korvezee A. E. , Dingemans P. , Dijkgraaf L. L. 
Published: September 2010

AbstractA simple approximate relation is derived for the temperature of the maximum occurring in the vapour‐pressure lines of saturated solutions of a number of non‐volatile substances of high melting point in a volatile solvent. The derivation is analogous to that for saturated solutions of one dissolved substance.This formula, although derived only for ideal mixtures, is found to give reasonably satisfactory results for a series of vapour‐pressure curves determined in this laboratory in non‐ideal systems.
Some 4.4′‐diformyl‐α,ω‐diphenoxyalkanes and their derivatives
Authors: Neish William J. P. 
Published: September 2010

AbstractSome 4,4′‐diformyl‐α,ω‐diphenoxyalkanes have been prepared by reacting the sodium salt of p‐hydroxybenzaldehyde with α,ω‐dibromoalkanes. These compounds were oxidised by alkaline potassium permanganate solution to the corresponding α,ω‐diphenoxyalkane‐4,4′‐dicarboxylic acids. The diformyl compounds were reacted with malonic acid yielding acrylic acid derivatives which have the melting‐point characteristics of mesomorphic substances. Hippuric acid has been shown to condense readily with the diformyl products yielding mono‐ and bis‐azlactones.
Action of cyclohexylamine on aromatic halogeno‐nitro‐compounds
Authors: Blanksma J. J. , Wilmink G. F. 
Published: September 2010

AbstractThe action of cyclohexylamine on 1‐chloro‐2‐nitrobenzene, 1‐chloro‐4‐nitrobenzene, 1‐chloro‐2,4‐dinitrobenzene, and 1‐chloro‐2,4,6‐trinitrobenzene has been investigated. The nitro‐cyclohexylaminobenzenes so found were nitrated and 2,4,6‐trinitrophenylcyclohexylnitramine, a colourless explosive product, similar to 2,4,6‐trinitrophenylmethylnitramine or the well‐known explosive, tetryl, was obtained.
The detection of small amounts of carbonate
Authors: van Dalen E. , de Vries G. 
Published: September 2010

AbstractAn apparatus design is described for testing for carbonates by means of baryta water, with which the sensitivity is improved to 1 μg in 0.05 ml and the certainty in judgement appreciably increased in comparison with the test by means of phenolphthaleine, by the removal of the disturbing action of the CO2 in the air.
The crystal structure of aluminium chloride
Authors: Ketelaar J. A. A. , MacGillavry C. H. , Renes P. A. 
Published: September 2010

AbstractAluminium chloride crystallizes in an ionic layer lattice. The dimensions of the monoclinic cell and the position of the chlorine atoms, given by Ketelaar in a previous investigation, are confirmed. The position of the Al‐atoms is different; instead of the ionic structure described in this paper, Ketelaar found a molecular lattice of “octahedral” molecules, fig. 1a. The structure appears to be in conflict with the result of the Raman investigation of solid AlCl3 by Gerding and Smit, which suggested a packing of “tetrahedral” molecules, fig. 1b.
Vapour‐liquid equilibria in ternary systems. IV. The system water‐ethanol‐trichloroethene
Authors: Reinders W. , de Minjer C. H. 
Published: September 2010

AbstractThe position of the ternary and of the three binary azeotropic points has been determined for the system water‐ethanol‐trichloroethene. The ternary point was found at: 6.1% water, 15.9% ethanol and 78.0% trichloroethene.The procedure for dehydrating 95% ethanol by means of benzene has been compared with that in which trichloroethene is used in place of benzene.
Vapour‐liquid equilibria in ternary systems. VI. The system water‐acetone‐chloroform
Authors: Reinders W. , de Minjer C. H. 
Published: September 2010

AbstractThe heterogeneous equilibria between liquid and vapour phases in the system water‐acetone‐chloroform have been investigated at a pressure of 760 mm. It appears that a saddle point occurs in the two‐liquids area of this system and that in addition a minimum occurs in the liquid surface. The positions of these two points have been determined. The vapour phase corresponding to the minimum does not form a minimum in the vapour surface as a result ow which this vapour is not condensed on rectification as a separate fraction. This minimum gives rise to the unusual phenomenon that the boiling point of some ternary mixtures does not rise on continued rectification but falls.
On the structure of p‐aminophenyl‐sulphonylguanidine and bis‐(p‐aminophenyl‐sulphonyl)‐guanidine
Authors: Goldschmidt St. , Ruttink J. 
Published: September 2010

AbstractThe preparation and properties of p‐aminophenylsulphonylguanidine and of bis‐(p‐aminophenylsulphonyl)‐guanidine are described in this article.
An apparatus for the colour measurement of dyed textiles
Authors: Heertjes P. M. , van den Heuvel E. , Lotichius J. 
Published: September 2010

AbstractProceeding from the Keuffel & Esser Color Analyzer a photo‐electric apparatus was designed, which can render good service for the colour measurement of dyed textiles.The reflection at one or more wave lengths is determined and taken as a colour coordinate when studying the relation between the quantity of dyestuff on the fibre and the resulting colour.
The colorimetric determination of nickel. As Ni(4) dimethylglyoxime
Authors: Haar K. Ter , Westerveld W. 
Published: September 2010

AbstractA description is given of a colorimetric determination of nickel as Ni(4) dimethylglyoxime, but in contrast to the customary methods, use is made of persulphate as oxidizing agent. The influence of other metallic ions has been investigated too.It appears that, of the elements investigated Ag must be removed, while the alkaline earth metals give a sulphate precipitate which can be removed by centrifuging. The determination of Ni in the presence of Mn, Fe, Cu and Co presents the greatest difficulties. In many cases we have succeeded finally in determining nickel in the presence of these elements without removing them. Thus it is possible to determine accurately 5% Ni and over in manganese, 0.25% and over in iron, 0.05% and over in copper and 0.05% and over in cobalt.In general it has been established that the highest accuracy is obtained when full attention is paid to the following points:
the avoidence of ammonia
the regulation of the amount of dimethylglyoxime
the acidity of the solution.
If one of these points is not in order, the degree of accuracy becomes less. This is the case in the determination of Ni in the presence of cobalt, copper, in which case the presence of ammonia is a necessary condition for the formation of the colour.It can be remarked that this method is extensively applied in our laboratory in the determination of Ni in chrome‐iron. Mo and W compounds.
Refractometric investigations on unbranched alkenes with a terminal double bond. The refraction equivalent of the >C  C< bond
Authors: Geldof H. , Wibaut J. P. 
Published: September 2010

AbstractThe preparation of the alkenes with a terminal double bond from C5to C10, C12, C16and C18inclusive in a high degree of purity is described. The refractive indices have been measured at 20° C and 25° C for 9 wavelengths and the densities measured at the same temperatures. After discussing the calculation of the refraction equivalent for the CH2group and the increment for the double bond according toEisenlohr, our experimental material has been used to calculate by the method of least squares, the refraction equivalents of the CH2group and the double bond for 9 wavelengths and the dispersion equivalents at 20° C and 25° C according to theLorentz‐LorenzandGladstone‐Daleformulae. The value for the terminal double bond [H2]1according to the method used byEykmanhas also been determined. In this way it has been possible to obtain accurate values for the refraction increment of the double bond, for the refraction equivalent of the CH2group and for the dispersion in the series of 1‐alkenes. The values we have obtained for the refraction equivalent of the double bond differ considerably from those ofEisenlohr, which are at present in general use.
Sur la Réactivité du Dibenzofuran et de Ses Isologues
Authors: Buu‐Hoï Ng. Ph. , Royer René 
Published: September 2010

AbstractDans ce travail, on examine le comportement du dibenzofuran vis‐à‐vis de quelques réactifs‐types: chlorures d acides gras, aromatiques ou hétérocycliques, brome libre, N‐bromosuccinimide. On compare ensuite la réactivité du dibenzofuran à celles de ses isologues tels que les carbazoles, le dibenzothiophène et le fluorène. Il est montré que le dibenzofuran possède une grande tendance à donner des dérivés 3,6‐disubstitués tout comme les carbazoles, mais sa réactivité est beaucoup moindre, quoique légèrement supérieure à celle du dibenzothiophène. Au cours de ces recherches, de nombreux corps nouveaux appartenant à la série du dibenzofuran, à celle du dibenzothiophène, et à celle du fluorène sont décrits; certains d'entre eux font l'objet d'études physiologiques (pouvoir oestrogène, par exemple).
The vapour pressure of aqueous solutions, saturated with respect to ammonium nitrate and sodium nitrate
Authors: Dingemans P. , Dijkgraaf L. L. 
Published: September 2010

AbstractThe vapour pressure of the four‐phase equilibrium: water vapour‐saturated solution‐solid NH4NO3‐solid NaNO3 has been measured from 10° C to the end of this line, i e. the eutectic of the binary system NH4NO3)‐NaNO3.We found this eutectic to lie at 121.1 ± 0.1° C and at a composition of 78.2 percents by weight of NH4NO3, and 21.8 percents by weight of NaNO3.The vapour pressure line has a maximum at 94.0° C and a pressure of 82.4 mm Hg.Previously deduced formulae for the calculation of maxima in vapour pressure lines and for the calculation of metastable eutectics, are found in this case also to give good agreement with the experimental results.
Researches on the alkoxy‐amino‐nitrobenzenes: V.) Fission of the methyl group in the nitration of 1‐alkyloxy‐2‐(p‐toluenesulphonyl)methylaminobenzenes with dilute nitric acid
Authors: Bosma G. S. K. , Verkade P. E. 
Published: September 2010

AbstractNitraiton of 1‐alkyloxy‐2‐(p‐toluenesulphonyl)methylaminobenzenes with 10% nitric acid at 80‐85° leads to the formation of 1‐alkyloxy‐2‐(p‐toluenesulphonyl)amino‐5‐nitrobenzenes. Under these conditions the methyl group attached to nitrogen is split off.
Carbonyl‐substituted naphthoquinones: Part II. Ketones of the type C10H7O2COCH2R
Authors: Spruit C. J. P. 
Published: September 2010

AbstractIn a previous publicationC. J. P. Spruit, Rec. trav. chim. 66, 655 (1947).
) we dealt with the preparation and properties of a number of derivatives of naphthyl‐2‐methylketoneThe name ‐ acetyl ‐ for the side chain, adopted in Part I for the sake of brevity, is abandoned for the substitution products. It is felt that the present nomenclature is not entirely satisfactory, especially for the quinones.
, substituted in various positions of the nucleus. This paper describes some compounds, derived from 1,4‐dihydroxynaphthyl‐2‐methylketone and 1,2‐dihydroxynaphthyl‐3‐methylketone by substitution in the methyl group.Although it has been found possible in some cases, to introduce the grouping ‐COCH2R directly into derivatives of naphthalene, by far the most convenient way has been found in the photochemical bromination of 1,4‐dihydroxynaphthyl‐2‐methylketone. The bromine atom in the resulting 1,4‐dihydroxynaphthyl‐2‐bromomethylketone is reactive, and may be replaced by other groups.
The structure of the formylation (OXO) products obtained from olefines and watergas
Authors: Keulemans A. I. M. , Kwantes A. , van Bavel Th. 
Published: September 2010

AbstractA number of pure olefines with up to 8 C atoms was subjected to formylation, a process by which CO and H2 are added to the olefine followed by hydrogenation of the aldehydes obtained to the corresponding alcohols. The structure of the alcohols was determined by converting them by careful dehydration and hydrogenation into the corresponding paraffins. The paraffins were analysed by analytical rectification and determination of physical constants. From the results a number of rules are derived, which make it possible to predict the structure of the alcohols to be obtained from a given olefine. The formylation reaction presents in many cases a convenient way of synthesizing new alcohols and hydrocarbons, some of which are described.
The chemistry of 2‐aminofluorene: 1. Reaction of 2‐aminofluorene with pyruvic acid
Authors: Neish W. J. P. 
Published: September 2010

Abstract2‐Aminofluorene condenses with pyruvic acid to yield the cinchoninic acid, 6‐methyl‐2,3‐(fluoreno)2′,1′‐pyridine‐4‐carboxylic acid. The compound is readily decarboxylated to 6‐methyl‐2,3‐(fluoreno‐2′1′)‐pyridine]. The possible significance of the cinchoninic acid structure for chemical carcinogenesis is discussed.
On the reaction between 5‐aminoacenaphthene and pyruvic acid
Authors: Neish W. J. P. 
Published: September 2010

Abstract6‐Methyl‐[acenaphtheno‐5′,4′‐2,3‐pyridine]‐4‐carboxylic acid has been prepared by reacting 5‐aminoacenaphthene with pyruvic acid in ethanol. The compound was decarboxylated by soda‐lime to give 6‐methyl‐[acenaphtheno‐5′,4′‐2,3‐pyridine].