bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fermentuntersuchungen in der Skeletmuskulatur bei Arteriosklerose und Endangites obliterans
Authors: Schmidt C. G. , Schlief H. , Hillenbrand H. J. 
Published: September 2010

AbstractIn Amputationspräparaten von Patienten mit fortgeschrittener Arteriosklerose und Endangitis obliterans wurde in unmittelbarer Nachbarschaft zu nekrotischen Anteilen der Skeletmuskulatur die Aktivität der Succino‐dehydrogenase, des Succinoxydase‐ und Cytochromoxydase‐Systems, der Hexokinase, ATP‐ase und der sauren und alkalischen Phosphomonoesterasen sowie der Gehalt an Glykogen bestimmt. Im Gegensatz zu den schweren klinischen Erscheinungen mit zum Teil ausgedehnten distalen Nekrosen blieb die Aktivität der Fermente in unmittelbarer Nachbarschaft der Nekrosen unverändert. In den Randzonen von Nekrosen ist dagegen neben starker Verminderung des Glykogenbestandes die Aktivität dieser Fermente herabgesetzt, die der alkalischen Phosphormonoesterasen gesteigert. Trotz der Tendenz zur Generalisierung weisen die Ergebnisse daraufhin, dass die Folgen der Gefässprozesse durch die Ausbildung von Kollateralen auf eng begrenzte Bezirke beschränkt sind.
Studies in contact potentials : I. Determination of the surface potential of some films on tungsten and mercury by the condenser method and a new form of the thermionic method
Authors: Mignolet J. C. P. 
Published: September 2010

AbstractThe author first decribes a new form of the thermionic method based on the shift of resistance characteristics. The resistance of the diode is measured with an A.C. bridge, care being taken to keep the emitter at constant temperature, even in the presence of gas. Cells suitable for tungsten deposits are described. The WH, WXe, and HgXe films have been studied by both the thermionic and the condenser method, and excellent agreement has been found for the surface potentials. For the WH and WN films, the surface potentials obtained are in grave disagreement with those of Bosworth 4) and of Bosworth and Rideal 5, 6) on tungsten wires. It is shown that Bosworth's value cannot refer to a WH film. The work function of a deposit stabilized between 293 and 428° K is close to that of a polycrystalline wire. Sintering increases the work function.
Studies in contact potentials,,: II. The competitive adsorption of hydrogen atoms and molecules on tungsten
Authors: Mignolet J. C. P. 
Published: September 2010

AbstractSurface potential measurements show the adsorption of hydrogen on tungsten to be complex. Besides the negative effect due to the familiar atomic film, a positive effect is observed.Experimental evidence reveals two important points, viz, (i) the positive effect is due to a molecular adsorption, and (ii) at the approach of saturation, the latter is able to compete with the atomic adsorption.The properties of the mixed adsorption of atoms and molecules on a surface are examined theoretically. Three main conclusions are reached. The competition between the atomic and molecular adsorptions may give rise to a special mode of adsorption, consisting in the replacement of atoms by molecules and taking place near saturation on a surface with practically no vacant sites. Through substitution, a molecular adsorption may compete with an atomic adsorption with double the differential heat of adsorption. The saturated mixed film is normally non‐stoichiometric. The model provides a satisfactory explanation of some peculiarities of the positive effect.The high heat of the molecular adsorption (up to 8 kcal/mole) is to be attributed essentially to the charge transfer forces, the contribution of which is much greater than that of the dispersion forces.Using the above ideas, it is shown that the evidence regarding the catalytic hydrogen exchange at low temperature is in favour of the Rideal mechanism.Substitutional adsorption is an activated process. It may account for a part of certain effects frequently attributed to dissolution.
A note on the mercuration of some types of furan derivatives
Authors: Verkade P. E. , Morel Th. , Gerritsen H. G. 
Published: September 2010

AbstractSuitable furan derivatives can be readily mercurated in β‐position. However, the introduction of a chloromercuri group in β‐position proceeds much more slowly than that in α‐position. Some applications of this difference in mercuration rate are discussed.
Intramolecular energy transfer in bimolecular reactions
Authors: Pritchard H. O. 
Published: September 2010

AbstractThe possible contribution of internal degrees of freedom to the activation of simple bimolecular reactions is discussed in terms of a classical model; it is suggested that existing experimental data on the reactions of halogen atoms with isobutane and of sodium atoms with the alkyl halides may prove to be examples of such behaviour.
Excelsin, edestin, and tobacco seed globulin crystals. Preparation, density, and X‐ray measurements
Authors: Drenth J. , Wiebenga E. H. 
Published: September 2010

AbstractThe vegetable proteins excelsin, edestin, and tobacco seed globulin were obtained from seeds, and the purity of the preparations was tested. Crystals were grown from solutions by dialysis against water. Their optical properties were examined and their densities were measured at different water contents. Single‐crystal X‐ray photographs were obtained from excelsin equilibrated with air of various relative humidities, and from tobacco seed globulin and edestin in both the dry and the wet state. The photographs were rather poor, except for excelsin, which, in a certain range of water content, shows reflections corresponding to spacings down to 4 Å. Its Laue symmetry is R 3m. A more detailed X‐ray investigation of excelsin, involving the introduction of heavy atoms into the structure, is in progress.The structures of the three proteins may be represented by approximate close packings of spheres. The molecular weights as calculated from the unit cell dimensions and densities of the dry crystals are 303,000 (± 10,000), 360,000 (± 20,000) and 350,000 (± 20,000) for excelsin, edestin, and tobacco seed globulin respectively.The relationship between the specific volume of excelsin and its water content is discussed.
The oxidation of phenols with copper‐amine catalysts and its relation to the mode of action of tyrosinase: I. The catalytic oxidation of monohydric phenols to orthoquinone derivatives
Authors: Brackman W. , Havinga E. 
Published: September 2010

AbstractIn an attempt to imitate the action of the enzyme tyrosinase by means of simple homogeneous catalytic systems we have found some rapid reactions which convert monohydric phenols directly into amine‐substituted orthoquinone derivatives. These reactions proceed rapidly at room temperature with molecular oxygen as an oxidant and copper‐amine complexes as catalysts. The reactions may be applied to a variety of phenols and of primary or secondary amines.It is argued that the monohydric phenols are primarily converted into the corresponding orthoquinones. Paraquinones are not formed or formed in traces only. The quinones are subject to rapid spontaneous addition reactions with the primary or secondary amines, thus giving rise to substituted catechols, which are oxidized to the corresponding orthoquinones.In the instances studied, the orthoquinone derivatives were formed in high yield. As they are converted easily in the corresponding phenazines and hydroxyquinones, the latter compounds may thus be synthesized in a convenient way from monohydric phenols and naphthols.The present paper deals with the nature of the reaction products only. Kinetics and reaction mechanism are discussed in following papers. The reactions studied in some detail are: The conversion of phenol into dimorpholino‐orthobenzoquinone (yield 64%) and of α‐ and β‐naphthol into 4‐morpholino‐1,2‐naphthaquinone (37 and 84%).The effect of morpholino substituents on the redox potential of quinones has been measured.The following new compounds are described in this paper: 4,5‐dimorpholino‐orthobenzoquinone, 2,3‐dimorpholinophenazine, 4‐morpholino‐1,2‐benzophenazine.
Syntheses, with the aid of (4‐pyridyl)‐magnesium chloride, of 4‐lithiopyridine and of 3‐lithioquinoline
Authors: Wibaut J. P. , Heeringa L. G. 
Published: September 2010

Abstract4‐Chloropyridine can be converted for about 70% into a complex magnesium compound, which reacts in the manner of a Grignard compound with aldehydes or ketones, forming (4‐pyridyl)‐carbinols; with orthoformic ester, (4‐pyridyl)‐methanal‐acetal is formed.The reaction of 4‐lithiopyridine with benzophenone and with ethyl benzoate respectively leads to the formation of (4‐pyridyl)‐diphenyl‐carbinol and to bis‐(4‐pyridyl)‐phenyl‐carbinol respectively. With aromatic nitriles, (4‐pyridyl)‐aryl ketones are formed.The reactions of 4‐lithiopyridine with cyanopyridines or with pyridine‐carboxylic esters lead to the formation of bis‐pyridyl ketones, e.g., bis‐(4‐pyridyl) ketone.Quinolyl ketones are obtained by starting from 3‐lithioquinoline.
Cerimetric determination of hypophosphite
Authors: Sastri M. N. , Kalidas Ch. 
Published: September 2010

AbstractA rapid method for the cerimetric determination of hypophosphite has been worked out, using silver salt as a catalyst. An excess of standard ceric sulphate solution is added to a solution containing hypophosphite acidified with sulphuric acid, and subsequently 2 ml of a 5% solution of Ag2SO4 in conc. sulphuric acid. The mixture is kept at the temperature of a boiling water bath for 20 minutes, and the unreacted eerie sulphate is determined with ferrous ammonium sulphate, after the mixture has been cooled.
Chemical behaviour of 3‐aminopyridine and of 3,5‐diaminopyridine. Syntheses of (3‐pyridyl)‐pyrazolones
Authors: Zwart C. , Wibaut J. P. 
Published: September 2010

AbstractThrough conversion of 3‐nitraminopyridine, two x‐nitro‐3‐aminopyridines are obtained in a very small yield. By bromination of 3,5‐bis‐(acetylamino) pyridine, a small yield of a dibromo derivative is obtained.From 3‐amino‐5‐bromopyridine the following compounds are prepared via the diazonium compound: 3‐bromo‐5‐fluoro‐pyridine, 3‐bromo‐5‐iodopyridine, 3‐bromo‐5‐cyanopyridine, and some azo dyestuffs.From (3‐pyridyl)hydrazine and ethyl acetoacetate 1‐(3′‐pyridyl)‐3‐methyl‐pyrazolone‐5 is obtained; from 3‐amino‐5‐bromopyridine, a (bromopyridyl)‐methylpyrazolone is obtained in an analogous manner.
New musk odorants: The structure of tert.amylated p‐cymene. A new synthesis of polyalkylindans. I
Authors: Weber S. H. , Spoelstra D. B. , Polak Ernest H. 
Published: September 2010

AbstractThe reaction of p‐cymene with tert.amyl alcohol or methylbutenes in the presence of sulphuric acid or with tert.amyl alcohol or tert.amyl chloride in the presence of aluminium chloride according to the Friedel Crafts method, has been found to yield a polymethylindan mixture consisting of 41% of 1,1,2,3,3,5‐hexamethylindan (XXI), 23% of 3‐ethyl‐1,1,3,5‐tetramethylindan (XX), and 12% of 1,1,3,3,5‐pentamethylindan (III). In addition, 1,2,3,3,5‐pentamethylindan (II) and 1,1,2,3,5‐pentamethylindan (I) have been synthesized.Introduction of an acetyl group into the aromatic nucleus of the first four indans results in indanyl methyl ketones having a musk odour, acetyl‐1,1,2,3,3,5‐hexamethylindan (XXVIII) being the most important of these.
Studies on vitamin D and related compounds IV: The pattern of the photochemical conversion of the provitamins D
Authors: Havinga E. , Koevoet A. L. , Verloop A. 
Published: September 2010

AbstractSolutions of about equal amounts of 7‐dehydrocholesterol‐3‐C14 and (inactive) lumisterol3 were irradiated with ultra‐violet light (265‐280 mμ) for short periods of time, resulting in approximately 10% conversion of the provitamin. Similar experiments were performed with labelled ergosterol (obtained by growing yeast in a medium containing acetate‐1‐C14), admixed with inactive lumisterol2 and tachysterol2. Isolation of the compounds present in the irradiated solutions was effected by precipitating the pro‐vitamin D with digitonin and separating the remaining components according to their different rates of reaction with maleic anhydride (tachysterol > vitamin D> lumisterol). The specific radio‐activities of the products isolated gave clear‐cut evidence that lumisterol does not play any part as an intermediate in the main route of the reaction provitamin D → tachysterol nor in the conversion provitamin D → vitamin D. Besides, lumisterol seems to be formed at a relatively low rate under the conditions employed, which are comparable with those generally used in vitamin D synthesis. As to tachysterol, here conclusions were somewhat less definite because this compound has rather a high rate of photochemical formation and decomposition and is difficult to purify. The specific activity measurements, however, strongly supported the conclusion that also tachysterol is not a necessary intermediate in the vitamin D formation. Thus the results are contradictory to the traditional scheme provitamin D magnified image lumisterol magnified image tachysterol magnified image previtamin D ⇄ vitamin D, and are strongly in favour of a reaction pattern of the following type: magnified image
A new method for the preparation of aromatic ISO thiocyanates
Authors: van der Kerk G. J. M. , Pluygers C. W. , de Vries G. 
Published: September 2010

AbstractA new method is given for the preparation of aromatic isothiocyanates from the corresponding dithiocarbamates. The latter compounds are converted into S‐(carboxymethyl) ‐dithiocarbamates, which spontaneously decompose at pH 7 in the presence of certain heavy metal ions to yield isothiocyanates. The reaction mechanism is discussed.
Synthesis of a potential oestrogen 1,3‐dimethyl‐7‐hydroxyphenanthrene‐2 carboxylic acid
Authors: van der Meer S. , Veldstra H. 
Published: September 2010

AbstractWith plant growth substances there exists a certain (spatial) equivalence, as to physiological activity, between tetrahydro α‐naphthoic acids and both β‐substituted α‐napthoic acids and 2,6‐disubstituted benzoic acids.It was tried therefore whether in the highly active oestrogens of the bisdehydrodoisynolic acid type the tetrahydro β‐napthoic acid part could be replaced by a di‐ortho substituted β‐naphthoic acid structure, while retaining activity.For this reason 1,3‐dimethyl‐7‐hydroxyphenanthrene‐2 carboxylic acid was synthesized. In the Allen‐Doisy test, however, only a slight indication of oestrogenic activity was found.
The electrodic behaviour of electro‐deposited manganese dioxide in solutions of different pH Part II
Authors: Issa I. M. , Khalafalla S. E. , Sadek E. A. 
Published: September 2010

AbstractThe potentials of MnO2, prepared by electro‐deposition on a platinum base and containing some lower oxide, vary with the pH of the solution. In acid solutions (pH 1‐5), ΔE/ΔpH amounts to 0.120 with an Eo′ = 1.38 volts at 25° C. From pH 7‐12, ΔE/ΔpH amounts to 0.060 with an Eo′ = 1.125 volts. In acid solutions the electrodes behave like MnO2/Mn+2, and in alkaline solutions like Mn(OH)3/Mn(OH)2 systems. The kinetics of the reaction in alkaline medium are discussed, and an equation expressing the variation of potential with time is developed.
A polarographic determination of glycyrrhizic acid in succus liquiritiae
Authors: Onrust H. , Jansen A. P. , Wöstmann B. S. J. 
Published: September 2010

AbstractA description is given of a quantitative polarographic method for determining the glycyrrhizic acid content of succus liquiritiae.The succus is dissolved in dioxane‐water and after hydrolysis with dilute add the hydrolysate is extracted with chloroform. An aliquot of this extract is evaporated to dryness and the residue is taken up in alcohol. Prom this solution a polarographic test solution is prepared.
Δ5‐Steroids and provitamins D with branched side‐chains, IV: The conversion of some Δ5‐steroids into provitamins D
Authors: Louw D. F. , Strating J. , Backer H. J. 
Published: September 2010

AbstractThe conversion of some new Δ5‐steroids1) into the corresponding provitamins D is described. The preparation of a provitamin D with a side‐chain ending in a tertiary amine function has been realized by reduction of the add amide with LiAlH4.The irradiated products show only very slight anti‐rachitic properties.
Sur des dérivés de la 4‐rhodananiline d'intérêt pharmacologique
Authors: Buu‐Hoï N. P. , Loc T. B. , Xuong N. D. 
Published: September 2010

AbstractLes propriétés chimiques de la 4‐rhodananiline ont été étudiées, et cette amine utilisée avec succès pour la synthèse de plusieurs composés possédant une activité antibactérienne importante contre divers microorganismes (bacilles tuberculeux, streptocoques, pneumocoques, méningocoques), et appartenant aux groupes des thiocarbanilides et des sulfanilamides.
Acid Anilides: II. The preparation of saturated fatty acid anilides from fatty acids and their esters
Authors: de Jonge A. P. , van der Ven B. , den Hertog W. 
Published: September 2010

AbstractIn the previous preliminary communicationA. P. de Jonge, Rec. trav. chim. 74, 760 (1955).on the chromatography of acid anilides an outline was given of the method.In this and forthcoming publications, details of the preparation, the ultraviolet and infra‐red absorption spectra and of the chromatography are described.In the present communication the preparation of saturated fatty acid anilides is described. The melting points of the pure acid anilides have been determined, and the relevant data compared with those given in the literature. In addition, the solubility in water of the first four members of the homologous series has been determined.In connection with analytical application, procedures are given for a quantitative preparation of the anilides starting from small amounts of acid or ester.
Acid Anilides: III. The ultra‐violet absorption spectra of fatty acid anilides
Authors: de Jonge A. P. , den Hertog W. 
Published: September 2010

AbstractIn this communication the ultra‐violet spectra in different solvents of the anilides of the homologous series of straight‐chain fatty acids from formic acid to capric acid (C10) and of the higher acids with an even number of carbon atoms as far as stearic acid (C18) are discussed.
Some fluoro‐substituted phenoxyacetic acids
Authors: Klaassens K. H. , Schoot C. J. 
Published: September 2010

AbstractThe preparation of 2,4‐dichloro‐6‐fluorophenoxyacetic acid, 2,4‐dichloro‐3‐fluorophenoxyacetic acid and 2,4‐dichloro‐5‐fluorophenoxyacetic acid is described.
Molecular volumes and structural chemistry
Authors: McGowan J. C. 
Published: September 2010

AbstractA list of atomic parachors is given and with its aid, parachors and molecular volumes of all kinds of molecules may be estimated. It is suggested that the atomic volume of a given element depends upon its electronic state so that the study of molecular volumes can throw light upon structural problems in chemistry, and this is illustrated by a consideration of certain compounds of the transition elements. In addition, examples are given to show how parachor values are likely to prove helpful in the study of ions in aqueous solutions.
The vibrational frequencies of S2Br2. Simultaneous spectrum in CS2 mixtures and infrared absorption spectrum
Authors: Ketelaar J. A. A. , Hooge F. N. , Blasse G. 
Published: September 2010

AbstractFrom the simultaneous infrared spectrum of CS2 and S2Br2 three fundamental vibrational frequencies of S2Br2 could be determined. A fourth fundamental frequency was observed in the infrared absorption spectrum of pure S2Br2, where also overtones and combination tones were observed. The S2Br2 spectrum was compared with the S2Cl2 spectrum.
Synthesis of 4 (2′‐piperidyl) butanediol‐1,2 and of some nitrogen‐substituted derivatives; the degradation of these diols by means of lead tetraacetate(Experiments on the synthesis of alkaloids from punica granatum, 5th communication
Authors: Wibaut J. P. , Hirschel M. I. 
Published: September 2010

Abstract4‐(2′‐piperidyl)butanediol‐1,2 (IX) and some of its nitrogen‐substituted derivatives were synthesized. These diols are subjected to a dehydrogenating degradation by means of lead tetraacetate. From IX is formed through this treatment, besides the formaldehyde to be expected, β‐(2‐piperidyl)‐propanal (I), a substance which, however, appeared to be unstable and could not be isolated as such. Dehydrogenating degradation of the N‐acetyl derivative, of the N‐benzoyl derivative or of the urethane of IX gives rise to the corresponding nitrogen‐substituted derivatives of I, which were previously obtained by Spielman et al. by a different route.
Crossed cannizzaro reaction with aromatic and heterocyclic aldehydes
Authors: Tiwari R. D. , Srivastava N. P. 
Published: September 2010

AbstractCrossed Cannizzaro reaction furnishes a very convenient and useful procedure for the reduction of aromatic and heterocyclic aldehydes to the corresponding alcohols. In the present investigations aromatic aldehydes related to naphthalene and heterocyclic aldehydes related to furane have been subjected to crossed Cannizzaro reaction. From alpha‐naphthaldehyde, alpha‐naphthylcarbinol has been obtained in much better yield than by methods hitherto reported. From 5‐methyl‐furfural, 5‐methyl‐furyl carbinol has been obtained in 60% yield by a process much simpler than those previously employed for its preparation. Concentration of alkali and the temperature of the reaction have to be varied in different reactions as in some cases higher concentration of alkali leads to resinification.
Preparation and proof of the constitution of 3,5‐di‐tert. butyltoluene
Authors: Geuze J. , Ruinard C. , Soeterbroek J. , Verkade P. E. , Wepster B. M. 
Published: September 2010

AbstractIt is proved that the hydrocarbon of m.p. 31‐32° obtained by di‐tert.‐butylation of toluene is 3,5‐di‐tert.butyltoluene.
Dielectric properties of dilute solutions of polyvinyl acetate in toluene
Authors: de Brouckère Lucia , van Beek L. K. H. 
Published: September 2010

AbstractMeasurements of the complex dielectric constant have been carried out for solutions of polyvinyl acetate in toluene at concentrations ranging from about 5 to about 11 g/100 ml, at temperatures ranging from 235 to 261° K. The molecular weights of the polymer samples were 22, 65, 100, and 200 times 104. These samples were characterized by viscosimetry, osmometry, light‐scattering and dissymmetry.It is found that the dipole moment of the molecule is proportional to the root mean square end‐to‐end distance and to the square root of the molecular weight. The frequency at which the loss curve has its maximum is independent of molecular weight, in contradistinction to the results predicted by Kirkwood and Fuoss and by Kuhn. This result can, however, be explained on the basis of the simple model used by Bueche and by Rouse.
Synthesis and properties of the chlorination products of methyl 4‐amino‐2‐hydroxy‐benzoate. I
Authors: van der Stelt C. , Suurmond B. G. , Th. Nauta W. 
Published: September 2010

AbstractExhaustive chlorination of methyl 4‐amino‐2‐hydroxy‐benzoate (XIII) (P.A.S. methyl ester) in a mixture of glacial acetic acid and hydrochloric acid (s.g. 1.19) yielded methyl 1,3,3,5,5,6‐hexachloro‐cyclohexanedione‐2,4‐carboxylate‐1 (XIV). Methyl 4‐amino‐3,5‐dichloro‐2‐hydroxy‐benzoate (XV), methyl 2‐amino‐4‐hydroxy‐benzoate (XVI), methyl 2,4‐dihydroxy‐benzoate (XVII), and methyl 3,5‐dichloro‐2,4‐dihydroxy‐benzoate (XVIII) could also be used as starting material for XIV. Reduction of XIV with stannous chloride yielded XVIII. With hypochlorous acid, XIV reacted with ring fission to form 1,1,2,3,5,5,5‐heptachloro‐3‐carbomethoxy‐pentanone‐4‐carboxylic acid‐1 (XIX). Both compounds XIV and XIX decomposed in alkaline medium and yielded monomethyl trichloro‐glutaconate (XX). In the first case the latter compound was accompanied with dichloro‐acetic acid, in the second case trichloro‐acetic acid was the other decomposition product. Glutaconic acid (XXI) was formed when XIX was reduced with sodium amalgam, while the structure of a 5‐carbomethoxy‐6‐trichloromethyl‐pyrone‐2 (XXII) is proposed for the reaction product of XIX with stannous chloride.