bluuebunny/crossref_metadata_2025_split huggingface dataset:
Note on the preparation of 4‐aminopyridine
Authors: Wibaut J. P. , Herzberg S. , Schlatmann J. 
Published: September 2010

AbstractContrary to the opinion of several authors, 4‐aminopyridine can be obtained by the method of Koenigs and Greiner in the yield mentioned by these workers, provided an excess of alkali be added to the reaction mixture from which the 4‐aminopyridine is to be separated.
Micro‐synthesis of cyanide from barium carbonate
Authors: Sixma F. L. J. , Hendriks H. , Helle K. , Hollstein U. , van Ling R. 
Published: September 2010

AbstractA new and very simple micro‐synthesis of HC14N from barium carbonate, ammonium chloride, and potassium is described. Yields of 94% ± 1.5% were obtained. Experiences with some other simple and fast methods described in the literature are reported as well.
Quelques nouvelles halogénations effectuées avec les N‐bromo‐ et N‐chlorosuccinimides
Authors: Buu‐Hoï Ng. Ph. 
Published: September 2010

AbstractOn décrit plusieurs nouveaux exemples d'application des N‐chloro‐ et N‐bromosuccinimide à la préparation de composés aromatiques ou hétérocycliques halogénés utiles pour la synthèse (amines aromatiques, éthers de naphtols et de polyphénols, dérivés de la pyridine, de l'indole et de la quinoléine). Il est montré que les N‐halogénoimides permettent souvent de réaliser commodément des monohalogénations dans des cas où l'halogéne libre donnerait une polyhalogénation.
Synthesis and some pharmacological properties of esters of some n‐alkyl homologues of tropinol and ψ‐tropinol: 3rd Communication on Derivatives of Tropinols
Authors: Siegmann C. M. , Wibaut J. P. 
Published: September 2010

AbstractThe syntheses described are those of a number of homologues of tropinone, viz. N‐ethyl‐nor‐tropinone, N‐n‐propyl‐nor‐tropinone, N‐iso‐propyl‐nor‐tropinone, and of a number of tropinols, viz. N‐ethyl‐norψ‐tropinol, N‐ethyl‐nor‐ψ‐tropinol, N‐n‐propyl‐nor‐ψ‐tropinol, and N‐isopropyl‐nor‐ψ‐tropinol. The benzoic esters of these tropinols are prepared, and also the d,l‐tropic ester of N‐ethyl‐nor‐ψ‐tropinol.The said. benzoic esters are investigated for local anaesthetic action with the aid of the cornea reflex.d,l‐Tropyl‐N‐ethyl‐nor‐ψ‐tropeine has neither a mydriatic nor a parasympatholytic effect.
On the theory of aromatic substitution: V. Note on the use of Hammett's equation for the correlation of rates of electrophilic and nucleophilic substitution reactions
Authors: Sixma F. L. J. 
Published: September 2010

AbstractA discussion is given of the use of Hammett's equation for the correlation of the rates of electrophilic and nucleophilic substitution reactions in the benzene nucleus. The discussion is based on a simplified theory of the inductive effect of certain types of substituents given in previous papers 2)3). It is shown that according to the theory the Hammett relation should hold for those cases where the influence of the substituent on the reaction rate is determined only (or for the greater part) by this “inductive” effect. In those cases where resonance interactions play a decisive role deviations may occur.
Séparation des aminoacides par chromato‐ graphie ascendante monodimensionnelle et leur dosage par photométrie directe sur le papier
Authors: de Wael J. , Cadavieco R. Diaz 
Published: September 2010

AbstractLes auteurs décrivent une méthode pour la détermination des aminoacides par photométrie directe des bandes colorées, obtenues par la chromatographie sur papier.Les facteurs qui influencent la reproductibilité des expériences ont été étudiés.L'analyse de deux protéines effectuée avec cette méthode donne des résultats qui correspondent aux chiffres, trouvés dans la litérature.
The polarographic reduction of conjugated hydrocarbons: IV. The mechanism of the reduction of various alternant and non‐alternant hydrocarbons
Authors: Hoijtink G. J. , van Schooten J. , de Boer E. , Aalbersberg W. Ij. 
Published: September 2010

AbstractThe current‐voltage curves of various alternant and non‐alternant hydrocarbons were measured in 75% and 96 % dioxane‐water. In many cases the limiting current of the first reduction wave corresponds to the overall addition of one electron. From the effect of the increase of the percentage of water and the addition of hydrogen iodide on the limiting current and on the half‐wave potential of the first and the second wave, evidence was obtained about the reduction mechanism. The primary steps of the reduction are: R + e →← R′ and R′ + e →← R″ the standard potential determined by the first electron addition is less negative than that of the second step.When the rate of proton addition to R′ is low with respect to the rate of diffusion of R′, the first wave is a one‐electron wave and the second wave involves the reduction to R″. When R′ reacts with a proton in the electrode surface layer, the reduction proceeds according to:magnified imageThe reduction mechanism is discussed in detail and compared with the experimental results reported in this paper or found by other investigators.
Studies on vitamin D, I. the synthesis of vitamin D3 3 C14
Authors: Havinga E. , Bots J. P. L. 
Published: September 2010

AbstractThe synthesis of vitamin D3 3 C14 is described. Special attention has been paid to the technique of the photochemical conversion of 7‐dehydro‐cholesterol 3C14 (small quantities) and to the isolation of the labelled vitamin D3 from the irradiation mixture. Some biological experiments are briefly communicated.
Aconic acid and related compounds: II. The reaction of aconic acid with diazomethane
Authors: Rekker R. F. , Brombacher J. P. , Nauta W. Th. 
Published: September 2010

AbstractFrom aconic acid with an excess of diazomethane a nitrogen‐containing compound is formed. The structure was established to be methyl 3,4‐(4′,5′‐Δ1‐pyrazolino) aconate. Heating of this compound resulted in the splitting off of a molecule of nitrogen and the formation of a methyl‐substituted aconic acid ester hitherto unknown in the literature.
Naphthodioxan (2,3‐dihydro‐naphtho‐[2,3]‐p‐dioxin), some derivatives and azo dyes. I
Authors: Heertjes P. M. , Ter Horst A. M. , Persijn J. M. 
Published: September 2010

AbstractThe preparation and orientation of naphthodioxan (2,3‐naphtho‐p‐dioxan (2,3‐dihydro‐naphtho‐[2,3]‐p‐dioxin)), 5‐, 6‐, and 7‐mononitro‐naphthodioxan, 5‐, 6‐, 7‐monoacetylamino‐naphthodioxan, as well as 5‐, 6‐, and 7‐naphthodioxan monosulphonic acid and some derivatives, are described in this paper.
The non‐existence of sesquiammonium phosphate
Authors: Ketelaar J. A. A. , Rundervoort H. J. , Lobatto J. L. , Hooge F. N. 
Published: September 2010

AbstractIt follows from measurements of the NH3‐pressures of preparations of ammonium phosphate with a composition intermediate between mono‐ and diammonium orthophosphate that no indication was obtained of the existence of a sesquiammonium orthophosphate, (NH4)3H3(PO4)2, as postulated by De Passillé. At temperatures above 135° C water is also separated off, with the formation of polyphosphates.
The concentration dependence of the electrophoretic mobility of soap micelles
Authors: Stigter D. 
Published: September 2010

AbstractThe dependence on the soap concentration of the micellar mobility is explained primarily by a solvent backflow. The observed limiting slope is corrected for the change of the true micelle mobility which is due to the variation of the effective ionic strength with the soap concentration. The corrected slope is interpreted in terms of a volume of solvent entrained by 1 gram of micellar soap. An approximate calculation confirms the experimental finding that the amount of entrained solvent becomes larger when the ionic strength of the solution decreases.
Ozone absorption and ozonolysis of cyclooctatetraene
Authors: Wibaut J. P. , Sixma F. L. J. 
Published: September 2010

AbstractAt −31° cyclooctatetraene absorbs 3.5 moles of ozone. Among the products of the ozonolysis of cyclooctatetraene, ethane‐1,1,2,2‐tetracarboxylic acid and succinic acid were found. The results may be interpreted either in terms of an equilibrium between cyclooctatetraene and bicyclo‐(4.2.0)‐octatriene or in terms of a reaction mechanism analogous to the one postulated by Friess and Boekelheide for halogen addition.
Steric effects on mesomerism: XIII. Preparation of 2,6‐dimethyl‐4‐nitroaniline
Authors: Wepster B. M. 
Published: September 2010

AbstractNitration of 2,6‐dimethyl‐(p‐toluenesulpho) anilide or 2,6‐dimethyl‐benzenesulphoanilide in aqueous acetic acid, followed by deacylation, gives 2,6‐dimethyl‐4‐nitroaniline in yields of 80‐90%. These and other procedures are discussed.The rate of deacylation of 2,6‐dimethyl‐4‐nitroacetanilide in sodium methoxide solution is in agreement with the considerable steric inhibition of mesomerism to be expected.
Preparation and constitution of some benzene derivatives containing the acetylamino and the methylsulphonyl group as substituents
Authors: Bolssens J. , Brouwers J. A. C. Th. , Choufoer J. H. , Kats A. , Verkade P. E. , Wepster B. M. 
Published: September 2010

AbstractThe preparation of a number of benzene derivatives containing the acetylamino and the methylsulphonyl group as substituents is described. Proofs for the constitution of the compounds obtained are furnished.
Glycerol‐α‐ and β‐monoiodohydrin
Authors: Hessel L. W. , van Lohuizen O. E. , Verkade P. E. 
Published: September 2010

AbstractFor the glycerol‐monoiodohydrins of m.p. 48‐49° and 53.5‐54.5° new methods of preparation are described. The last‐mentioned compound has thus become reasonably accessible for the first time. The statements in the literature as to the constitution of the first‐mentioned compound are discussed. Unambiguous evidence for the constitution of the two compounds is furnished: the compound of m.p. 48‐49° is the α‐isomer, that of m.p. 53.5‐54.5° the β‐isomer.
The influence of oestrogens on the protein and lipid metabolism of the mouse uterus, studied with acetate‐1‐C14
Authors: Emmelot P. , Bosch L. 
Published: September 2010

AbstractThe in vitro incorporation of tracer from acetate‐1‐C14 into proteins, cholesterol, and fatty acids of isolated uterine segments was estimated 20 hours after an in vivo treatment of ovariectomized mice with 0.1 μg oestrone, 17β‐oestradiol or oestriol.The hormone‐treated animals showed a significantly higher incorporation of C14 than the untreated groups.In general the following order of activity was noted: 17β‐oestradiol> oestrone oestriol.
The heats of combustion, formation and isomerization of propanethiol‐1, propane‐thiol‐2 and 2‐thiabutane
Authors: Hubbard Ward N. , Waddington Guy 
Published: September 2010

AbstractBy use of a rotating bomb calorimeter the isothermal energy change (‐ΔUc°) at 25 °C of the reaction C3H8S(l) + 13/2 O2(g) + 52H2O(l) → 3CO2 + H2SO4.55H2O(l) has been measured for propanethiol‐1 (I), propanethiol‐2 (II), and 2‐thiabutane (III). The combustion results, supplemented by vapor pressure, heat of vaporization and gas imperfection data, gave values (in kcal.mole−1) of the standard heats of formation at 25° C of each of the three C3H8S compounds, in the liquid and ideal gaseous states, as follows: I(l), ‐23.69 ± 0.16; I(g), ‐16.04 ±0.16; II(l), ‐25.12 ± 0.15; II(g), ‐18.04 ± 0.16; III(l), ‐21.71 ± 0.27; III(g), ‐14.07 ± 0.27. The reliability of the derived heats of isomerization is discussed.
The rate of condensation of some tripeptide methyl esters in solution
Authors: Sluyterman L. A. Ae. , Veenendaal H. J. 
Published: September 2010

AbstractThe condensation rate of a few tripeptide methyl esters in methanol has been studied at 65° C. The peptide esters with a glycyl residue at both ends have been found to be equally reactive, regardless of the nature of the amino acid residue in the middle. A side chain situated on one of the terminal amino acid residues decreases the reaction rate (table I).
Volumetric determination of uranium in poor ores
Authors: Smit W. M. , Klinkhamer J. 
Published: September 2010

AbstractThe conditions necessary to prevent interference of Fe with the oxidimetric titration of U have been derived on the basis of calculations regarding the relations between the redox potential and the pH. The method of calculation may be applied to other possibly interfering ions. It is shown that a successful determination of both U and Fe can be carried out in a solution with an atomic ratio Fe/U of 1000 and containing only 2 mg of U per 150 ml. By using the “dead stop end point” indication method, U and Fe may be determined separately without previous separation and without any pretreatment but reduction by a common Jones reductor.
The chlorination of 4‐amino‐2‐hydroxy‐benzoic acid
Authors: v. d. Stelt C. , Suurmond B. G. , Nauta W. Th. 
Published: September 2010

AbstractIn an attempt to prepare 4‐amino‐3,5‐dichloro‐2‐hydroxy‐benzoic acid (I) from 4‐amino‐2‐hydroxy‐benzoic acid (II) by a chlorination reaction, it was found that the isolated reaction product was identical with 2,4,4,6,6‐pentachloro‐cyclohexene‐1‐dione‐3,5 (III). Exhaustive chlorination of 2,4‐dihydroxy‐benzoic acid (IV) led to the same 1,3‐dihydroxy‐benzene derivative. (I) could be prepared by chlorination of 4‐acetylamino‐2‐hydroxy‐benzoic acid (V) to 4‐acetylamino‐3,5‐dichloro‐2‐hydroxy‐benzoic acid (VI) and subsequent saponification of the latter compound. By converting I into 3,5‐dichloro‐2‐hydroxy‐benzoic acid (VII) and into 3,5‐dichloro‐2,4‐dihydroxy‐benzoic acid (VIII), the 3,5‐position of the chlorine atoms in I and VIII could be proved.
Naphthodioxan, some derivatives and azo dyes: II
Authors: Heertjes P. M. , Ter Horst A. M. , Persijn J. M. 
Published: September 2010

AbstractSome derivatives of naphthodioxan, 5‐amino‐naphthodioxan, and of naphthodioxan‐7‐sulphonic acid, including azo dyes, mostly substituted in the 5‐ and 10‐positions, are described in this paper.
Chemistry of acetylenic ethers X. Note on the use of ethoxy‐acetylene for the preparation of acid anhydrides
Authors: Arens J. F. , Doornbos T. 
Published: September 2010

AbstractSome years ago it was found that ethoxy‐acetylene (ethoxy‐ethine) is a very mild reagent for the preparation of carboxylic anhydrides.Afterwards we observed that also non‐carboxylic acids are transformed into their anhydrides by this reagent.2 RCOOH + HC ≡ C‐OC2H5 → (RCO)2O + CH3COOC2H52 RSO3H + HC ≡ C‐OC2H5 → (RSO2)2O + CH3COOC2H5From a recent paper by E. R. H. Jones and co‐workers 2) it appears that these investigators examined the same reactions. Experiments with several mono‐ and dibasic carboxylic acids and with a sulphonic acid are recorded. In addition to these examples we give below a description of the use of ethoxy‐acetylene for the preparation of tetraethyl pyrophosphate from diethyl phosphate.
The solubility of bilirubin
Authors: Overbeek J. Th. G. , Vink C. L. J. , Deenstra H. 
Published: September 2010

AbstractThe titration curve of a suspension of bilirubin with NaOH has been determined and analysed. A value of 5 × 10−11 mole/l for the solubility of undissociated bilirubin has been derived from the titration.
On the rate of oxidation of di‐alkylsulphoxides in monolayers
Authors: Blokker P. C. , Paar E. 
Published: September 2010

AbstractIn order to obtain more information on the conditions under which the reactivity of substances in a liquid/air interface is affected, the oxidation of di‐alkylsulphoxides in monolayers by very dilute potassium permanganate solutions was studied.In a few cases with expanded films, where the energy of activation could be calculated, this energy was low. With increasing packing density of the molecules in the film the pseudo‐unimolecular reaction constant increased; this is probably caused by an increase in the entropy of activation.
The action of diazoacetic ester on pyridone‐2: A new synthesis of 2‐pyridoxyacetic acid
Authors: Maas J. , de Graaff G. B. R. , den Hertog H. J. 
Published: September 2010

AbstractEthyl 2‐pyridoxyacetate is obtained as chief product, together with a small amount of N‐(2‐pyridonyl) acetic ester, by reacting pyridone‐2 with ethyl diazoacetate.
Synthèse du 1,1,2,2‐tétradeutérioacénaphtène et du 9,9‐dideutériofluorène
Authors: Buu‐hoï Ng. Ph. , Eckert B. , Jacquignon P. 
Published: September 2010

AbstractOn décrit la préparation, à partir de l'acénaphtènequinone et de l'oxyde de deutérium, du 1,1,2,2‐tétradeutérioacénaphtène par la méthode de Clemmensen; Iorsque la réduction est incomplète, on aboutit au 1‐oxo‐2,2‐dideutérioacénaphtène. Une réduction analogue de la fluorénone conduit au 9,9‐dideutériofluorène.
Carbamates. II. Reactions‐ of 2,4 di‐isocyanato‐toluene
Authors: Gaylord Norman G. , O'Brien John J. 
Published: September 2010

AbstractThe dicarbamates prepared by the reaction of various monofunctional alcohols and phenols with 2,4‐diisocyanatotoluene are well‐defined solids which are useful in the characterization of these hydroxy compounds.
Untersuchungen über Derivate von 2,3‐Dihydro‐pyran‐2,4‐dion: (2. Mitteilung)
Authors: Kögl F. , Salemink C. A. 
Published: September 2010

AbstractIn Fortführung unserer Untersuchungen über die antibakterielle Wirkung von homologen Dehydracetsäuren mit normalen Seitenketten wurden in der vorliegenden Arbeit auf analoge Weise Derivate mit verzweigten Seitenketten dargestellt. Im allgemeinen zeigen diese Derivate bei verschiedenen Bakterienarten eine gesteigerte Hemmwirkung.
The ozonolysis of quinoline, 6,7‐dimethylquinoline, 5,8‐dimethylquinoline, and 2,3‐dimethylquinoline in connection with the reactivity of the bonds in the ring system
Authors: Wibaut J. P. , Boer H. 
Published: September 2010

AbstractWhen ozone acts on quinoline and on some dimethylquinolines, the main reaction consists in an attack on the benzene ring, via a 5,6‐7,8‐diozonide; this follows from the products obtained after ozonolysis. The 5,10‐, 6,7‐, and 8,9‐bonds are not affected by ozone.The reactivity of the ring system of quinoline towards ozone therefore greatly resembles the reactivity of the ring system of naphthalene towards the same reagent. The 5,6‐ and 7,8‐bonds in the quinoline ring system behave in the same manner towards ozone as do the α,β‐bonds in the ring system of naphthalene.Upon the ozonolysis of 2,3‐dimethylquinoline, besides glyoxal there is also formed dimethylglyoxal; this points to the fact that by the side of the main reaction a side reaction takes place, in which the pyridine ring is attacked through addition of a molecule of ozone to the 3,4‐bond.
The dynamic state of the thyroid gland in cases of hypertension diagnosed by means of radioactive iodine
Authors: Fateeva M. N. 
Published: September 2010

AbstractIn cases of hypertension, the absorption of I131 by the thyroid gland can be determined by direct measurement.More than 60% of the patients exhibit a hyperfunction of the thyroid gland in the first stage of hypertension, while the gland's function is reduced in two‐thirds of the cases during the third stage.
Local measurement of I131 uptake in the thyroid gland
Authors: Jaspers A. M. J. , Marcuse H. R. 
Published: September 2010

AbstractBased on a new development of Geiger‐Müller tubes, a collar‐shaped device is described, which can be applied round the patient's neck in order to measure directly the uptake of I131 in the thyroid gland. Methods are indicated for calibrating and for measuring the corrections due to the background and the activity in the blood.
The I131 thigh neck clearance test in relation to drug administration
Authors: Maclagan N. F. , Meade B. W. 
Published: September 2010

Abstract500 patients have been examined by the I131 thigh neck clearance test, and the results correlated with clinical data and estimations of basal metabolic rate. The test consists in the oral administration of 30 μc of I131, followed by alternate neck and thigh counts under defined conditions over the following one to two hours. The clearance represents the ratio of the rise in neck counts over a 60 minute period divided by the mean thigh count taken at the same time, and gives normal figures of from 1 to 9.In untreated patients there is good correlation in the B.M.R., but as with other radioactive tests of thyroid function, discrepancies occur after various forms of medical treatment. A. number of goitrogens and blocking agents were tested for their ability to limit the retention of I311 by the thyroid if given at the conclusion of the test. Of these potassium iodide gave the best results but is not recommended for routine use.
The influence of prominal on the thyroid function of the rat
Authors: Schwarz F. 
Published: September 2010

AbstractThe experiments show the rather surprising fact that prominal does not depress, but enhance the I131 uptake of the thyroid gland. The radioactivity of the gland was determined by in vitro measurements.Further we used an apparatus constructed in our laboratory for the determination of thyroid activity in the living rat.The results obtained in this way are discussed.
Oxydation phosphorylante et carence en thiamine
Authors: Frei J. , Wermuth R.‐M. 
Published: September 2010

AbstractNous avons étudié dans le présent travail l'oxydation phosphorylante dans des homogénéisats de foies de rats normaux et carancés en thiamine. La formation de triphosphate d'adénosine a été déterminée par la mesure sur chromatogrammes sur papier de l'incorporation de phosphate radioactif dans le phosphate labile. Nous obtenons un abaissement significatif de la phosphorylaton de l'A.D.P. dans l'homogénéisat de foies de rats carencés en vitamine B1 pendant l'oxydation du citrate et du succinate. La consommation d'oxygène est diminuée également, mais elle n'est pas significative pendant les 15 prèmieres minutes des expériences. Nos recherches se poursuivent pour voir si nous avons affaire à une lésion au niveau des mitochondries provoquant le départ de facteurs indispensables.
Beiträge zur Methodik der fluorometrischen Porphyrinbestimmung
Authors: Weber K. , Valić F. 
Published: September 2010

AbstractEs wird die fluorometrische Apparatur, besonders hinsichtlich ihre Verwendung für Porphyrinbestimmungen kritisch besprochen. Auf günstige Lichtquellen und einwandfreie Filterkombinationen wird hingewiesen. Es werden Lösungen und Adsorbate von Rhodamin B an Filterpapier als Ersatz für Standarde von Koproporphyrin bei der fluorometrischen Analyse empfohlen und diesbezügliche Eichkurven und Umrechnungstabellen mitgeteilt.
Eine Apparatur zur Hochspannungs‐Papierelektrophorese
Authors: Werner G. 
Published: September 2010

AbstractEs wird eine Apparatur beschrieben, mit der die Papierelektrophorese bei Spannungen bis 10 000 Volt und Wanderungswegen bis 1 Meter möglich ist. Eine besondere Art des Aufbringens der Substanzlösung auf den Papierstreifen wird beschrieben, sowie über eine Einrichtung berichtet, mit welcher es möglich ist, besonders lange Papierstreifen gleichmässig und reproduzierbar anzufeuchten. Die Leistungsfähigkeit wird an Trennungen von Aminosäuren, Peptiden, Zuckern und anorganischen Salzen gezeigt.
The detection of thyroxine and related compounds on paper chromatograms by optical methods
Authors: Maclagan N. F. , Bowden C. H. , Wilkinson J. H. 
Published: September 2010

AbstractThe ceric sulphate‐arsenious acid reagent has been applied to the detection of thyroxine and triiodothyronine on paper chromatograms. The sensitivities achieved were such as to suggest that this reagent might enable physiological concentrations of these substances to be detected. Preliminary experiments on the extraction of the iodine components of plasma are described.
Die Bedeutung routinemässiger Phosphatasebestimmungen in Klinischen Labors: Eine neue, einfache Standard‐Methode
Authors: Raabe Siegfried 
Published: September 2010

AbstractEiner routinemässigen Anwendung der meisten bisherigen Methoden stand entgegen, dass sie zu umständlich, z. T. auch mit biochemischen Fehlermöglichkeiten behaftet sind. Deshalb entwickelten wir eine Standard‐Methode, die exakte Werte liefert und trotzdem technisch so einfach ist, dass sie auch in einfach eingerichteten Labors bequem und in grossen Reihen ausgeführt werden kann. Routinemäszige Phosphatase‐Bestimmungen erlauben dem Laborleiter wertvolle Hinweise für den Kliniker; sie sollten daher mehr Eingang in den klinischen Labors finden.