bluuebunny/crossref_metadata_2025_split huggingface dataset:
Phosphatidic acids and derivatives: IV). Synthesis of α‐glycerophosphatidic acids, starting from glycerol‐α‐iodohydrin
Authors: Hessel L. W. , Morton I. D. , Todd A. R. , Verkade P. E. 
Published: September 2010

AbstractDiacylglycerol‐α‐iodohydrins react smoothly with silver dibenzyl phosphate in the presence of benzene, with the formation of diacylglycerol‐α‐phosphoric acid dibenzyl esters. Upon hydrogenolysis in alcoholic suspension or solution in the presence of a palladium/active carbon catalyst the latter substances yield the corresponding diacylglycerol‐α‐phosphoric acids and toluene.
The exchange of chlorine between the green chromium (III) chloride and chloride ions
Authors: van der Straaten H. , Aten A. H. W. 
Published: September 2010

AbstractThe exchange of chlorine between the green chromium (III) chloride and chloride ions in aqueous solution has been investigated using radioactive chlorine 34 and 38 as tracers. Only in very concentrated solutions a slight exchange has been found.
On the theory of aromatic substitution: IV. The orienting influence of substituents in naphthalene derivatives
Authors: Sixma F. L. J. 
Published: September 2010

AbstractThe method previously described 2) for estimating the “inductive” effect 3) of substituents is applied to electrophilic substitution reactions of naphthalene derivatives. It is shown that a + I‐substituent 4) either at carbon atom 1 or 2 directs the entering substituent mainly to the 5‐position; the positions 8 and 4 possess a smaller reactivity. A ‐ I‐substituent at carbon atom 1 directs to the positions 4 and 8, whereas a ‐ I‐substituent at carbon atom 2 orients mainly to the 1‐position. These rules are in accordance with the available experimental data.The theory is applied more extensively to the substitution reactions of the mono‐, di‐ and tri‐nitronaphthalenes; the agreement with the experimental data is very satisfactory.
Structure of α.ω‐diphenylpolyenes: III Molecular orbital calculations on the members of the series Ph‐(CH = CH)n‐Ph with n = 0, 1, 2, 3, 4, and 5
Authors: Drenth W. 
Published: September 2010

AbstractThe LCAO‐MO method in first approximation was used to calculate for Ph‐(CH = CH)n‐Ph with n = 0, 1, 2, 3, 4, and 5 bond lengths, resonance energies, the frequency of the first u.v. absorption band, and the probability of transition for this band. For the compounds with n = 0, 1, and 2 the calculations were extended to a second approximation. The semiempirical value obtained from heats of combustion for βo′, the exchange integral including overlap for a bond between adjacent carbon atoms in the benzene molecule, amounts to about ‐73 kcal/mole. It is in satisfactory agreement with the theoretically calculated value of ‐77kcal/mole. βo′, from spectral data has the same order of magnitude.
Side reactions in the polymerization of α‐amino acid n‐carbonic anhydrides. Titration data of polyglycine and polyalanine
Authors: Sluyterman L. A. Æ. , Labruyère B. 
Published: September 2010

AbstractPolyglycine and polyalanine obtained by polymerization of their N‐carbonic anhydrides often appeared to contain more acid groups than amino groups. This is ascribed, at least partly, to the formation of hydantoin groups.A small amount of 2,5‐diketopiperazine was isolated from polyglycine.A discussion of the results and their bearing upon the calculation of molecular weights is given.
Sur la condensation des esters maloniques monosubstitués avec les α‐aminopyridines
Authors: Buu‐Hoi Ng. Ph. , Declercq Monique 
Published: September 2010

AbstractOn montre que la condensation de Tschitschibabin des esters maloniques monosubstitués avec la 2‐aminopyridine et la 4‐méthyl‐2‐aminopyridine n'est pas entravée par la présence de radicaux encombrants dans la molécule de ces esters, et que l'on aboutit, dans tous les cas examinés, aux dérivés de l'homopyrimidazole attendus. Ces observations plaident en faveur de l'hypothèse selon laquelle le mécanisme de la condensation de Tschitschibabin comporte l'intervention des formes énoliques des esters maloniques.
Synthesis and stability of o,o′‐dimethoxybenzoyl peroxide
Authors: Crowdle James R. , Osgood Edmond R. , Gaylord Norman G. 
Published: September 2010

Abstracto,o′‐Dimethoxybenzoyl peroxide (97% purity) has been synthesized in a 50% overall yield from salicylic acid. The compound has been found to be thermally unstable and shock sensitive
Note sur la bromuration de quelques cétones arylaliphatiques
Authors: Rothstein R. , Schneck G. , Binovic K. , Stoven O. 
Published: September 2010

AbstractLa bromuration des éthers benzyliques des dihydroxyphényl alcoylcétones, par la bromo‐succinimide, se fait avec de très bons rendements et sans coupure partielle des groupes benzylés.
Mechanism of the alkaline decomposition of sulphonylnitrosamides: (IInd communication on sulphonylnitrosamides)
Authors: de Boer Th. J. , Backer H. J. 
Published: September 2010

AbstractThe alkaline decomposition of p‐tolylsulphonylmethylnitrosamide with potassium hydroxide in ethyl alcohol yields chiefly diazomethane, together with ethyl and potassium p‐toluenesulphonate. These products are compatible with a pseudo‐catalytic mechanism in which the ethylate ion plays a main role.
The reactivity of halogen atoms occupying positions 3 and 5 in 2,4‐dihydroxypyridine: A new synthesis of 5‐chloro‐2,4‐dihydroxypyridine
Authors: den Hertog H. J. , Combé W. P. , Kolder C. R. 
Published: September 2010

AbstractA survey is given of the rearrangements occurring during the heating of the monobromo and monochloro derivatives of 2,4‐dihydroxypyridine, substituted at positions 3 or 5, with hydrobromic and hydrochloric acid.In this connection the reactivity of 3,5‐dibromo‐ and 3,5‐dichloro‐2,4‐dihydroxypyridine has been investigated. It has been found that the halogen atoms at position 3 are replaced by hydrogen in both compounds when they are heated with an aqueous solution of hydrobromic acid to which sodium bisulphite, aniline or another halogen bonding substance is added. When, on the contrary, the dihalogeno derivatives are treated with hydrogen in the presence of a palladium catalyst, the halogen atoms occupying the 5 position are replaced by hydrogen.These results open up an easy route for the synthesis of 5‐chloro‐2,4‐dihydroxypyridine from 2,4‐dihydroxypyridine as a starting substance.
Additions nucleophiles au bis‐tertiobutylsulfonyl‐acétylène, II. Propriétés du groupe sulfonyle XLIV
Authors: Strating J. , Backer H. J. 
Published: September 2010

AbstractUn mémoire antérieur a décrit l'addition d'alcools et de mercaptannes au bis‐tertiobutylsulfonyl‐acétylène. La réaction d'amines sur cette disulfone est beaucoup plus vive et, en même temps, plus compliquée. Les produits d'addition que donnent les amines aromatiques sont à même de réagir avec un excès d'amine, en perdant un reste de tertiobutylsulfonyle sous forme d'acide sulfinique. Ainsi il est possible d'introduire successivement deux amines différentes.Les amines réagissent Également sur les Éthers qui se forment par addition d'alcools à la disulfone acétylénique; l'hydrolyse donne naissance aux mêmes amides que l'on obtient en hydrolysant les adducts d'amines.
The identification of di‐ and polyamines and aminohydroxy compounds as fission products of azodyestuffs
Authors: Frahm E. D. G. 
Published: September 2010

AbstractDi‐ and polyamines, as well as aminohydroxy compounds in dilute solutions resulting from the reduction of azodyestuffs, can be isolated and identified by benzoylation of such solutions, either immediately or after separation of one or more of the other fission products. When the benzoylation has been carried out properly, the yield of the benzoyl derivatives is almost quantitative. The melting points of several benzoyl compounds, not mentioned in the literature, are tabulated.The method was successfully applied while investigating the constitutions of many azodyestuffs, mainly of the Chlorantine Fast and the Coprantine ranges and their equivalents.
The meta‐para ratio of the inductive effect in benzene derivatives
Authors: Rooda R. W. , Verkade P. E. , Wepster B. M. 
Published: September 2010

AbstractStarting from the rate constants of the alkaline hydrolysis of methyl meta‐ and para‐N‐oxide‐dimethylamino benzoate and with the aid of data of various nature from the literature, the generalization is arrived at that as a rule the influence of the negative inductive effect from the meta and from the para position differs little, with some tendency towards predominance of this effect from the meta position.Some applications of this generalization are discussed.
The gravimetric determination of cholesterol in woolwax
Authors: Knol H. W. 
Published: September 2010

AbstractThe analytical determination of cholesterol in woolwax alcohols by means of the formation of an insoluble addition product with digitonin gives unreliable results, caused by the co‐precipitation of the “triterpene” alcohols. 10‐20% of the precipitated fraction may consist of “triterpene” woolwax alcohols. A correction for this co‐precipitation cannot be given, because no connection exists between the contents of cholesterol and “triterpene” alcohols in woolwax. For a more reliable determination of cholesterol the photometrically measured colour reaction of Liebermann‐Burchard should be preferred.
Thermal diffusion of liquid mixtures of pure hydrocarbons i. the performance of a microthermal diffusion column
Authors: van Schooten J. , van Nes K. 
Published: September 2010

AbstractThe theoretical approach of separation by thermal diffusion is somewhat hampered by the lack of sufficient experimental data.In an effort to meet this want, a microthermal diffusion column was constructed, which enables the composition of the mixture to be determined all along the column. This column, which is described in the present paper, has 43 outlets, placed along its length, from which samples can be taken.With the aid of this column the separation of some binary hydrocarbon mixtures was studied after various time intervals. Results so far have confirmed current theories describing thermal diffusion as a counter current fractionation process.The degree of separation in the stationary state is expressed by the concentration gradient at the point of inflection of the concentration‐length curve. From this concentration gradient the thermal diffusion constant D′ is calculated for the various mixtures studied.
The action of acid chlorides on 4‐chloro‐ and 4‐hydroxypyridine ‐n‐oxide and some of their derivatives
Authors: den Hertog H. J. , Maas J. , Kolder C. R. , Combé W. P. 
Published: September 2010

AbstractThe action of phosphorus oxychloride and sulphuryl chloride on 4‐chloro‐ and 4‐hydroxypyridine‐N‐oxide and on their 3‐chloro‐derivatives has been investigated.Under the conditions chosen the acid chlorides reacted differently. Phosphorus oxychloride replaced the hydroxyl group by chlorine and promoted the deoxidation of the N‐oxide group. Sulphuryl chloride removed the oxygen atom of the N‐oxide group, introducing at the same time chlorine at one of the α‐positions; further it replaced the hydrogen atoms at the β‐positions by chlorine, but not the hydroxyl group.A substance whose analysis pointed to the formula C5Cl7NO was isolated from the reaction mixture obtained by heating 4‐hydroxypyridine‐N‐oxide, its 3‐chloro, 3,5‐dichloro or 3‐nitro derivative with an excess of sulphuryl chloride. It is assumed to be 1,2,2′,3,3′,5,6‐heptachloro‐1,2,3,4‐tetrahydropyridone‐4, inter alia because of its reduction yielding 2,3,5,6‐tetrachloro‐4‐hydroxypyridine. The last‐mentioned compound was identified with preparations synthesized from pentachloropyridine and 4‐amino‐2,3,5,6‐tetrachloropyridine. The substance C5Cl7NO was also obtained when 4‐hydroxypyridine was treated with sulphuryl chloride.
The interaction between urea and carboxylic acids in solution: The ternary systems water ‐ urea ‐ n‐valeric acid and water ‐urea ‐ 2‐methyl butyric acid (isovaleric acid)
Authors: Ketelaar J. A. A. , Loopstra B. O. 
Published: September 2010

AbstractThe liquid miscibility gaps in the ternary systems water‐urea‐n‐valeric add and water‐urea‐2‐methyl butyric add respectively are determined at 25° C.The heats of mixing of n‐butyric add and of isobutyric acid with an equimolar amount of water and with a concentrated solution of urea in water are determined.No significant difference in the behaviour of branched and unbranched adds towards urea in solution is observed, contrary to former statements.
The partition of HNO3 between water and three organic solvents
Authors: Kooi J. 
Published: September 2010

AbstractThe partition of nitric acid between water and diethylether, methylisobutyl ketone, and dibutyl carbitol respectively has been measured at 25.0 ± 0.1° C in the range from 1 to 10 N. The experimental data are presented as mass and as concentration (mol/l) partition coefficients. The results seem to be accurate to within 1%.
An improved method for the spectrochemical determination of zinc in blood
Authors: Addink N. W. H. 
Published: September 2010

AbstractIn order to determine the concentration of zinc in blood with greater precision than before, a method has been worked out of which the main points are:(a) complete evaporation of the metal out of a weighed amount (of 10 mg) of bloodash;(b) a constant arc temperature independent of a varying sodium content of the bloodash;(c) a rotating anode of a definite shape.By using this method concentration values have been determined with a St. dev. of 5%. As for the absolute concentration of zinc in various blood samples, values found in applying the method of successive additions, agreed satisfactorily with those determined chemically.
A Base‐line for nucleic acid turnover in isotopic studies
Authors: Bassir O. 
Published: September 2010

AbstractIn this experiment, the “decay” with time of injected radio‐active phosphorus, P32, in various fractions of the rat liver is studied, with a view to discovering an acid‐soluble fraction which would appear to be an “immediate precursor” of ribonucleic acid and deoxyribonucleic acid.It is shown that the Specific Activity‐Time curve of liver inorganic phosphate does not satisfy the requirements of an “immediate precursor” of the nucleic acids. On the other hand, a compound, chemically identifiable with adenylic acid, has been shown to be more suitable for use as a base‐line for the turnover of these acids.
N15‐investigations on the mechanism of nitrogen interaction in normal and immobilized organisms
Authors: Heilskov N. S. C. , Schønheyder F. , Olesen K. 
Published: September 2010

AbstractThe mechanism underlying the negative N‐balance provoked by immobilizing bed rest has been studied by means of excretion data for N15 after administration of N15‐labelled glycine to human subjects under normal conditions (N‐equilibrium) and during immobilization (negative N‐balance). The results seem to indicate that the negative N‐balance during immobilization is primarily based upon a reduced synthesis of tissue proteins, while the rate of breakdown of these proteins is unchanged.
Emploi des rayonnements, et en particulier de l'infrarouge, dans l'identification des molecules en biologie
Authors: Guillot Marcel 
Published: September 2010

AbstractOn trouvera un grand nombre de renseignements techniques utiles sur toutes les méthodes dont il est question dans cette conférence dans:Physical Methods of Organic Chemistry, vol. I, Part II de A. Weissberger; Interscience Publishers Inc., New‐York, 1949.En ce qu concerne en particulier l'infrarouge, on lira l'article de W. West dans l'ouvrage précédemment indiqué, p. 1332 à 1371.Sur l'emploi général de l'infrarouge pour l'identification des molécules, on pourra lire la revue d'ensemble de A. Berton, “Les spectres infrarouges en biologie et en pharmacie”, Annales pharmaceutiques françaises, 11, 129, (1953).Enfin, l'ouvrage de J. Lecomte, “Le Spectre infrarouge”, Edit, de la Société “Journal de Physique”; Les Presses universitaires, Paris, 1928, reste classique, bien que déjà dépassé.Au sujet des méthodes d'analyse immédiate utilisables, on pourra consulter avec profit le volume V du même ouvrage de Weissberger, qui a été rédigé par H. G. Cassidy (1951).On trouvera dans ces différentes publications une bibliographie complète de ces questions, bibliographie qui est trop vaste pour que nous puissions la fournir ici.
Acquisitions récentes relatives aux dosages et a l'identification des 17 céto‐stéroides et des corticoides
Authors: Henry R. 
Published: September 2010

AbstractAussi bien pour le dosage des corticoïdes que pour celui des 17‐céto Stéroïdes neutres urinaires ou sanguins les méthodes d'hydrolyse biologique sont préférables. La Chromatographie utilisant l'alumine ou la Chromatographie sur papier peuvent être appliquées à la séparation des 17‐ céto Stéroïdes et des corticoïdes. Les produits élués sont caractérisés en utilisant des réactions colorées ou la spectrophotométrie infrarouge et ultraviolette. L'intérêt clinique de ces dosages est succinctement rappelé.
Ein einfacher Apparat zur semiquantitativen Bestimmung von Koproporphyrin im Harn
Authors: Donath W. F. 
Published: September 2010

AbstractEs wird eine einfache fluorometrische Methode für die semiquantitative Bestimmung von Koproporphyrin im Urin beschrieben. Diese Methode kann sehr gut angewendet werden bei der Ermittlung von Fällen von Bleivergiftung.
Étude des protéines sériques de malades traités avec la clorpromazine, par la méthode de l'èlectrophorèse différentielle, en clinique psychiatrique
Authors: Dubost P. , Pascal Suzette 
Published: September 2010

AbstractÉtude effectuée dans le cadre des recherches poursuivies à la clinique des Maladies Mentales et de l'Encéphale de la Faculté de Médicine de Paris (Pr. Jean Delay) pour dépister les modifications biologiques que pourrait entraîner l'administration prolongée de la clorpromazine, recherches qui seront l'objet d'un mémoire d'ensemble ultérieur. L'électrophorèse différentielle a été pratiquée en même temps sur des malades témoins sans traitement et sur des malades traités à la clorpromazine, examinés soit avant et pendant le traitement, soit seulement en cours de traitement.L'absence de modifications significatives du chiffre des protéines sériques, au cours d'un traitement prolongé à la clorpromazine, permet de penser que ce mèdicament n'a pas d'action nocive marquée vis‐à‐vis des fonctions protéiques hépatiques.
Die Proteinämie und Proteinurie beim Nephrosesyndrom untersucht mit Hilfe der Papier‐Elektrophorese
Authors: Alvarez Justo Gonzalez , de la Gandara Joaquin Otero 
Published: September 2010

AbstractWir studierten mit Hilfe der Papierelektrophorese das elektrophoretische Bild im Blut und Harn bei Individuen mit Nephrosesyndrom. Die Untersuchungen wurden bei Kranken der Madrider Universitätklinik für innere Medizin vorgenommen.
The effect of sex hormones on histaminase measured with a micro‐volumetric method
Authors: Kapeller‐Adler R. 
Published: September 2010

AbstractNatural oestrogens activate histaminase, unlike the synthetic oestrogens and most of the other steroid hormones and chorionic gonadotrophins which inhibit histaminase. A micromethod that allows comparative investigations of the effect of equimolar solutions of steroids on histaminase extracts has been elaborated and is described with dose‐response curves. The significance of the results obtained with regard to hormonal effects on histaminase activity in normal and toxaemic pregnancy is also discussed.
Synthetic oxytocics V. Quinine derivatives
Authors: Pouwels H. , Veldstra H. 
Published: September 2010

AbstractContrary to expectations, based upon a certain structural resemblance between 3‐(piperidyl‐(2)‐methyl‐)indoles (II) and quinine (III), the change from quinine and related alkaloids to their 9‐deoxy bases (viathe 9‐chloro‐9‐deoxy derivatives) does not enhance the oxytocic activity. This activity remains practically constant, whereas these variations in structure cause a total loss of antimalarial activity. By oxidation of the deoxy bases, the unknown carboxylic acids of type IV (oxytocically inactive) were obtained.
Gas‐liquid partition chromatography
Authors: Dijkstra G. , Keppler J. G. , Schols J. A. 
Published: September 2010

AbstractThe identification and determination of different aliphatic substances by means of a suitable system of gas chromatography is described.Gas‐chromatographic separations of different series of carboxylic acid esters from propionic‐ up to stearic acid ester, alcohols from pentanol up to hexadecanol, and aldehydes from pentanal up to decanal are described.Silicone grease or paraffin wax is used as the liquid phase with celite as a carrier. The separations have been carried out at temperatures up to 230° C, which made the use of atmospheric pressure at the outlet possible. Hence the fractions separated can be conveniently collected. A quantitative determination of milligram amounts in mixtures of methyl esters is described.The minimal detectable amounts as estimated for methyl propionate are of the order of micrograms.
Gas hydrates ‐ approximate relations between heat of formation, composition and equilibrium temperature lowering by “inhibitors”
Authors: Pieroen A. P. 
Published: September 2010

AbstractRelations are derived between the heat of formation of a gas hydrate, its composition and the depression of the three‐phase equilibrium temperature upon addition of a “third component”, such as an alcohol. Although none of these equations is fully exact they are in reasonable agreement with experimental data. The treatment is limited to constant pressures.
The oxidation of phenols with copper‐amine catalysts and its relation to the mode of action of tyrosinase: II. The oxidation of naphthols with tertiary amines as catalysts
Authors: Brackman W. , Havinga E. 
Published: September 2010

AbstractIn this paper the catalytic oxidation of a number of naphthols is described, copper‐collidine and copper‐pyridine complexes being used as catalysts.Generally speaking two types of reactions must be considered. The first type involves a direct oxidation of the naphthol by the cupric complex to free radicals which dimerize and give rise to dinaphthols. Some of these are oxidized further to naphthalene analogues of diphenoquinone (dinaphthones and bisnaphthalene indigo's). All these reactions may be accomplished by the cupric complex itself, and the function of oxygen is simply to regenerate the cupric‐ from the cuprous state.In the second type of reactions, which involve the formation of 1,4‐naphthaquinone derivatives, oxygen (or hydrogen peroxide formed from it) probably plays a more specific rôle. Hydrogen peroxide may also be responsible for some unidentified products formed from the dinaphthol derivatives.The naphthols investigated were: naphthol‐1, naphthol‐2, 2‐ethyl‐1‐naphthol, 4‐methyl‐1‐naphthol, 2‐ and 4‐chloro‐1‐naphthol. The products are listed in table 1. The redox potentials of 4‐(2′‐hydroxy‐1′‐naphthyl)‐1,2‐naphthaquinone and of diethyldinaphthone have been measured.The spectra of bis‐methylnaphthalene‐indigo and of natural indigo appear to be strikingly similar.The following new compounds are described: 4‐(di‐β‐naphthoxyl)‐1,2‐naphthaquinone and its phenazine, bis‐4‐chloronaphthalene indigo, 2,2′‐dichlorodinaphthone, bis‐4‐methylnaphthalene indigo, a black compound (C30H18O4)X.
On the reaction of phenylethyne with formaldehyde On the reaction of phenylethyne with formaldehyde
Authors: Beets M. G. J. , Heeringa L. G. 
Published: September 2010

AbstractThe acid‐catalyzed reaction of phenylethyne with formaldehyde has been studied. From the complex reaction mixture a number of compounds have been isolated. Their structures and the mechanism of their formation are discussed. Preliminary results on the acid‐ and alkali‐catalyzed reactions of acetophenone with formaldehyde are reported.