bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and reactivity of N‐(4‐pyridonyl)oxyacetic acid
Authors: Bojarska‐Dahlig H. N. , den Hertog H. J. 
Published: September 2010

AbstractN‐(4‐Pyridonyl)oxyacetic acid was prepared in a yield of almost 60% by reacting 4‐hydroxypyridine‐N‐oxide with chloroacetic acid in alkaline medium.The structure of N‐(4‐pyridonyl)oxyacetic acid follows from its decomposition when treated with sodium hydroxide solution and from its catalytical reduction, both reactions yielding 4‐hydroxypyridine.A remarkable decomposition reaction of the acid occurs when it is treated with diazomethane. 4‐Methoxypyridine is formed while carbon dioxide and formaldehyde are split off.The anomalous course of a condensation of the 3,5‐diiodo‐derivative of 4‐hydroxypyridine‐N‐oxide with chloroacetic acid is explained.
Silver oxide as an oxidant for hydrazine macro‐ and micro‐determination of hydrazine
Authors: Sant B. R. 
Published: September 2010

AbstractVolumetric estimation of hydrazine, based upon its oxidation with a known excess of silver nitrate in alkaline medium and titration of the excess against standard thiocyanate by the Volhard's method, is described. Alternatively, the precipitated silver may be dissolved in nitric acid and titrated with thiocyanate. The method is applicable down to 0.4 mg N2H4.
On the acid and basic sites in silica alumina cracking catalysts
Authors: Stigter D. , Bosman J. , Ditmarsch R. 
Published: September 2010

AbstractAdsorption phenomena of AlCl3 on silica in aqueous suspensions have been studied by means of micro‐electrophoresis and titration techniques.In neutral and alkaline suspensions, pH > 4‐5, aluminium hydroxide precipitates on the outer surface of the silica particles and in the course of time may migrate through the pores of the particles. The rate, of migration is highest in alkaline solution.Evidence is presented that an acid alumino‐silica complex is formed.
Non‐equilibrium interaction of proteins with sodium and potassium ions measured by ultrafiltration
Authors: van Oss C. J. 
Published: September 2010

AbstractUne méthode d'ultrafiltration est donnée, permettant de déterminer les interactions physico‐chimiques de Na· et K· avec des protéines dissoutes, sans qu'un équilibre ne soit atteint. Les résultats obtenus sont parfois différents des résultats que donnent les Interactions d'équilibre entre Na·, K· et les protéines. Parmi les protéines dissoutes étudiées il y en a qui ont une préférence pour Na· dans un système de non‐équilibre.La méthode d'ultrafiltration a également servi pour calculer la quantité totale des cations retenus par des protéines à des pH donnés: elle a permis D'observer une augmentation de la quantité de cations retenus par des protéins dès qu'une solution de ces dernières se gélifie.
Protein synthesis in mammalian cells with particular reference to antibody formation
Authors: Askonas Brigitte A. 
Published: September 2010

AbstractRecent work concerned with protein biosynthesis in mammalian systems is reviewed. Antibody protein was chosen as an example of a specific protein and its formation and secretion was studied in slices of lymphoid and reticuloendothelial organs of immunized animals. [J. L. Simkin and T. S. Work, Biochem. J. 67, 617 (1957).
C] Amino acids added to the incubation medium appeared in intracellular antibody extractable with saline after a lag period of 10–15 min, suggesting that antibody is first formed bound to subcellular particles. There is a longer lag period (more than 30 min) before the newly formed radioactive antibody is secreted by the cell into the extracellular medium.Plasma cells which are responsible for antibody formation have a highly organized endoplasmic reticulum similar to hepatic and pancreatic cells known to actively secrete proteins. Microsomal fraction contains bound antibody which may be released by destroying the structure of the particles and it probably represents the site of antibody formation. So far antibody synthesis by microsomes could not be demonstrated since mild damage or breakage of the cells stopped incorporation of radioactive amino acids into antibody extractable with saline.
On an enzymatic reaction between amino acids and nucleic acid and its possible role in protein synthesis
Authors: Hoagland Mahlon B. 
Published: September 2010

AbstractEvidence has been presented which contributes more detail to our picture of the likely intermediate steps in the synthesis of protein. Thus it would appear that, following activation of animo acids by ATP and specific enzymes, there occurs a transfer of the activated animo acid from adenylamino acid to RNA‐amino acid. The RNA‐amino acid then appears to become associated with the microsomal ribonucleoprotein particles through the intermediation of guanosine triphosphate, with resultant condensation of amino acids to form protein. This scheme is a working hypothesis, and the present paper calls attention to some of the areas where more rigorous proof of the suggested reactions is required.
The reaction of 2‐chlorocyclohexanol with brucine
Authors: Zeelen F. J. , Kronenberg M. E. , Havinga E. 
Published: September 2010

Abstract2‐Chlorocyclohexanol‐1 forms a clathrate compound with brucine. This reaction provides a means of obtaining chlorocyclohexanol ‐ and related compounds ‐ that are partially resolved into optical antipodes.
The structure of the compound C10Cl12
Authors: Zijp D. H. , Gerding H. 
Published: September 2010

AbstractThe dipole moment, infrared, Raman and ultraviolet spectra of C10Cl12 have been determined. Possible structures are discussed. Our results indicate a caged structure as put forward by McBee et al. of symmetry D2h or C2h. Approximate calculations of the normal frequencies have been made on the assumptions of a simplified model.
On the phosphate metabolism of yeast
Authors: van de Pol J. H. , Berends W. 
Published: September 2010

AbstractYeast grown in a medium containing Na2H32PO4 but relatively little inorganic and organic phosphate, shows a disproportionate specific activity of P in different cell‐fractions.In a medium containing glucose and phosphate the fungicide actidione has no effect on the phosphates exchange of yeast containing 32P, nor is the distribution of 32P over the constituents of the cell affected.
The effect of ultraviolet light on some components of the nucleic acids: II: In rapidly frozen solutions
Authors: Beukers R. , Ylstra J. , Berends W. 
Published: September 2010

AbstractThe sensitivity of some of the bases occurring in the nucleic acids to U.V. irradiation in a frozen solution is different from that in an aqueous solution. Thymine especially shows a very high sensitivity. The implications of the results are discussed.
Syntheses and properties of aromatic nitroso‐compounds
Authors: Mijs W. J. , Hoekstra S. E. , Ulmann R. M. , Havinga E. 
Published: September 2010

AbstractMeasurements of spectra in the visible region at different concentrations and temperatures of a series of substituted nitrosobenzenes are reported. Syntheses of the nitroso‐compounds are described. The relationship between steric inhibition of resonance and the tendency of nitroso‐compounds to form dimers is discussed.
Chemistry of acetylenic ethers ‐XXXI. A simplified procedure for the preparation of ethyl β‐chlorovinyl ether
Authors: Arens J. F. , Vegter J. , de Boer T. 
Published: September 2010

AbstractEthyl β‐chlorovinyl ether can be obtained easily from chloroacetaldehyde diethylacetal by heating with potassium pyrosulphate. The product contains a large proportion of the cis‐isomer. The required acetal has been prepared from paraldehyde, alcohol and chlorine.The method has been applied also for the synthesis of butyl β‐chlorovinyl ether.Ethyl β‐chlorovinyl ether can also be prepared continuously by passing chloroacetal vapour at 220‐230° over pumice impregnated with 4% of potassium bisulphate.The conversion of trans‐ into cis ethyl β‐chlorovinyl ether by irradiation in the presence of traces of bromine is described.
Chemical studies on insecticides VI : The rate of hydrolysis of some phosphorus acid esters
Authors: Ketelaar J. A. A. , Gersmann H. R. 
Published: September 2010

AbstractThe rates of alkaline hydrolysis of a number of phosphorus acid esters have been measured. The correlation between these rates and such phenomena as the presence of an energy‐rich phosphate bond, inhibition of the action of cholinesterase and ali‐esterase is discussed.
Ionylamines III . Catalytic hydrogenation of ionones in the presence of ammonia or amines and the determination of the position of the > C  C < bond in dihydro‐α‐, dihydro‐β‐ and tetrahydro‐ψ‐ionylamines
Authors: Kralt T. 
Published: September 2010

AbstractThe course of the catalytic hydrogenation of ionones in the presence of ammonia or amines has been investigated. In this way it has been possible to determine the position of the remaining > C = C< bond in the dihydro‐α‐, dihydro‐β‐ and tetrahydro‐ψ‐ionylamines (I, II and III) described previously I. T. Kralt, H. D. Moed and J. van Dijk, Rec. trav. chim. 77, 177 (1958). II. H. D. Moed, T. Kralt and J. van Dijk, ibid. 77, 196 (1958).
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Etude Potentiométrique en Milieu non Aqueux de Quelques Amino‐Acides N‐Tritylés et N‐Benzylés
Authors: Legrand Maurice , Delaroff Vladimir , Bolla Paul 
Published: September 2010

AbstractLes dérivés N‐tritylés ou N‐benzylés des amino‐acides étant insolubles dans l'eau, il est possible d'opérer dans un mélange de solvants organiques renfermant 1% d'eau pour déterminer des potentiels de demi‐neutralisation. Les variations de ces potentiels correspondent sensiblement à celles des constantes d'équilibre acido‐basique.Les valeurs de ΔEK ainsi mesurées permettent, en particulier, de déterminer la position des substituants tritylés ou benzylés introduits sur des α,ω‐diamino acides.
Absorption spectra in the visible and U.V. region of potassium permanganate and potassium manganate in solution and their application to the analysis of mixtures of these compounds
Authors: Den Boef G. , van der Beek H. J. , Braaf Th. 
Published: September 2010

AbstractValues for the molecular extinctions of manganate and permanganate in aqueous solution have been determined.A method is described for the spectrophotometrical analysis of mixtures of manganate and permanganate in alkaline solutions.
Steric effects on mesomerism: XIX . A Comparison of some properties of a number of N‐mono‐n.alkyl‐ and N,N‐di‐n.alkylanilines
Authors: Brouwers J. A. C. Th. , Bijlsma S. C. , Verkade P. E. , Wepster B. M. 
Published: September 2010

AbstractResearches on the ultra‐violet absorption spectrum, the basic strength, and the molecular refraction of N‐mono‐n.alkyl‐ and N.N‐di‐n.alkylanilines and on the behaviour of the last‐mentioned compounds in nitrosation and coupling experiments have taught that the presence of one or two n.alkyl groups with a considerable number of carbon atoms ‐ such as the n.hexadecyl group ‐ does not cause any perceptible steric inhibition of mesomerism. A priori, as is discussed below, the possibility of the occurrence of this phenomenon did have to be taken into account in the cases in question.
Researches on plant growth regulators, XXIII. Structure/activity, VIII. Phosphonic and phosphonous acids
Authors: van de Westeringh C. , Veldstra H. 
Published: September 2010

AbstractPhosphonic and phosphonous acids of the indole and the naphthalene series were synthesized and assayed in the pea test and the avena straight growth test.3‐Indolylmethylphosphonic acid proved to be the most active compound among the phosphonic acids, the activity of which was generally surpassed by that of the corresponding phosphonous acids.Compared herewith, substituted phenoxy‐methylphosphonic acids and also arsonic acids of the naphthalene series were practically inactive.
Tetrazole analogues of physiologically or pharmacologically active carboxylic acids
Authors: Brouwer‐Van Straaten B. , Solinger D. , van de Westeringh C. , Veldstra H. 
Published: September 2010

AbstractTetrazole analogues of several carboxylic acids, active physiologically or pharmacologically in various ways, were synthesized and assayed for analogous or antagonistic action.No appreciable activity in either sense was found.
The condensation of rhodanine and derivatives with polycyclic aromatic aldehydes
Authors: Allan F. J. , Allan G. G. 
Published: September 2010

AbstractThe condensation products of rhodanine, 3‐ethylrhodanine and 3‐phenyl‐rhodanine with various polycyclic aromatic aldehydes have been prepared with a view to obtaining compounds with increased bacterial and fungicidal properties. The aldehydes were chosen to yield products of similar skeletal configuration to the less accessible alkyl substituted compounds. It is known that substituted benzylidene‐rhodanine derivatives show increased bacterial activity and the products obtained, by virtue of their structure, should show activity similar to di‐ and tetra‐alkyl substituted derivatives. Condensations were carried out in both ammoniacal and acid media and crystalline coloured condensation products were obtained in good yield.
Cupric tetramminosulphate. II. Dissociation pressures
Authors: Anous M. M. T. 
Published: September 2010

AbstractThe dissociation pressure of cupric tetramminosulphate was measured at different temperatures. Log10 P is plotted against 1/T, gave a curve which could be divided into two intersecting lines of different slopes, indicating that the two molecules of ammonia liberated in the decomposition of the tetrammine to give the diammine are set free in two stages; at temperatures lower than 50° the tetrammine decomposes giving the triammine; at higher temperatures, it gives the diammine directly. The heat content change of the system “Δ H” was calculated for each step and found to be 6.1 and 25.5 kcals per molecule for the liberation of the first and second molecules ammonia respectively at low temperatures.The heat of formation of CuSO4.3NH3 was calculated as 285.3 kcals per molecule.
The absolute configuration of (‐)‐homostachydrine from alfalfa
Authors: Beyerman H. C. 
Published: September 2010

AbstractRecently Wiehler and Marion isolated from the seeds of alfalfa (Medicago sativa) the laevo‐rotatory methyl betaine of hexahydropyridine‐2‐carboxylic acid, for which they suggested the name of (‐)‐homostachydrine.This compound has now been prepared from L‐(‐)‐hexahydropyridine‐2‐carboxylic acid (L‐(‐)‐pipecolic acid). (‐)‐Homostachydrine therefore possesses the L‐configuration.
Chemical studies on insecticides IX: Infra‐red absorption spectra of phosphorus acid esters
Authors: Ketelaar J. A. A. , Gersmann H. R. 
Published: September 2010

AbstractThe infra‐red absorption spectra of a number of phosphorus acid esters have been measured. The assignment of a number of frequencies is discussed. A shift in the phosphoryl stretching vibration to higher frequency is observed in “energy‐rich” phosphorus acid esters.
Synthesis and pharmacological properties of O‐acetylsalicylamides
Authors: Kralt T. , Moed H. D. , Ariens E. J. , Hendriksen Th. W. J. 
Published: September 2010

AbstractThe synthesis of a series of N‐substituted O‐acetylsalicylamides (Tables I and II) is described. Most compounds possess weak antipyretic activity and strong spasmolytic activity.
A synthesis of the lactone of 5‐pyridoxic acid
Authors: Wuest H. M. , Bigot J. A. , de Boer Th. J. , Wal B. V. D. , Wibaut J. P. 
Published: September 2010

AbstractThe reduction of dimethyl 2‐methyl‐3‐hydroxypyridine 4,5‐dicarboxylate (I) with sodium borohydride and aluminium chloride gives no pyridoxol but a precursor i.e. the lactone II, corresponding to 5‐pyridoxic acid. No isomeric lactone (III) corresponding to 4‐pyridoxic acid was isolated.
Reaction of benzhydrol with urea and thiourea
Authors: Rahman Aziz‐Ur , Singh Rama Kant 
Published: September 2010

AbstractThe reaction between benzhydrol and urea resulting in the formation of N,N′‐bis(diphenylmethyl)urea and bis(diphenylmethyl) ether, has been studied with a view to substantiate the reaction mechanism suggested by Rahman and Farooq1 for the formation of the former in a reaction between benzilic acid and urea, based on decarboxylation of benzilic acid.The reaction mechanism postulated by Dannenberg and Rahman2 for the formation of N,N′‐bis(diphenylmethyl) thiourea (III), bis(diphenylmethyl) disulphide (IV) and bis(diphenylmethyl) sulphide (V) in a reaction between benzilic acid and thiourea, based mainly on initial benzhydrylation (diphenylmethylation) of thiourea to yield N‐(diphenylmethyl) thiourea (VIII) and also S‐(diphenylmethyl)‐isothiourea (VII), which undergo appropriate changes to yield eventually III, IV and V, has been substantiated by the identity of the products of reaction between benzhydrol and thiourea, with III, IV and V. Further confirmation of the mechanism is afforded by the isolation of a small amount of VII from the reaction product of benzhydrol and thiourea. The comparative mechanisms of the reaction between benzilic acid and thiourea on the one hand and of that between benzhydrol i.e. ‘decarboxylated benzilic acid’ and thiourea, on the other, are discussed.
Reaction products of primary β‐hydroxyamines with carbonyl compounds: XIV Reaction of 3‐Aminopropanol with Carbonyl Compounds
Authors: Bergmann Ernst D. , Kaluszyner A. 
Published: September 2010

AbstractWith the aid of the molecular refraction and the infrared absorption, the structure of the condensation products of 3‐aminopropanol with 14 carbonyl compounds has been investigated. In some cases, tetrahydro‐1,3‐oxazines, in some Schiff bases, and in some, mixtures of these two possible products have been obtained. On the whole, there is a greater tendency towards the formation of cyclic structures from 3‐aminopropanol than from 2‐aminoethanol; in both cases the tendency is increased by alkylation of the carbon skeleton of the aminoalcohol.The tetrahydro‐1,3‐oxazines are as susceptible to hydrolysis as the oxazolidines.
Phloroglucinol from picryl chloride
Authors: Heertjes P. M. 
Published: September 2010

AbstractThe conversion of picryl chloride into phloroglucinol has been studied by a combination of methods for the same or similar substances already presented in the literature. The reduction of picryl chloride to 1,3,5‐triaminobenzene with tin in hydrochloric acid could be reproduced quite well and gave, in combination with the well known hydrolysis of the triamino‐compound, a possible method.Contrary to the literature the reduction of picryl chloride with iron (Béchamp's method or excess of hydrochloric acid) was not satisfactory. A rather elegant method has been found based on the electrolytical reduction of picryl chloride followed by immediate conversion of the 2,4,6‐triamino‐1‐chlorobenzene hydrochloride, so formed, as dissolved in the catholyte, to phloroglucinol, by heating in a slightly alkaline solution containing stannous chloride and hydroxide at temperatures of 140‐160° C.
Investigations on sterols XII: The conversion of dihydrovitamin D2‐I and D2‐II into dihydrotachysterol2
Authors: Westerhof P. , Buisman J. A. Keverling 
Published: September 2010

AbstractThe results are presented of investigations on preparing dihydrotachysterol2 from dihydrovitamins D2‐I and D2‐II.
A simple re‐evaluation of the hammett ϱσ relation
Authors: van Bekkum H. , Verkade P. E. , Wepster B. M. 
Published: September 2010

AbstractStarting from ten selected σ values, a large number of ϱ values is calculated; these ϱ values in their turn serve to calculate other σ values. The results prove that the concept of “duality of σ constants” is erroneous. In those cases in which a substituent enters into mesomeric para interaction with the reaction centre, a multiplicity of (exalted) σ values is observed; this holds for +M as well as for −M substituents. In the absence of mesomeric para interaction σ values are reasonably constant; the mean of such σ values (σn) is listed.It is demonstrated that σ values are, in general, not suitable for judging mesomeric para interactions, and should be replaced by the (free) energy difference term

involving not only the exaltation of σ, but ϱ and T as well. Several important applications of this concept are discussed, illustrating the way in which the ϱσ relationship can be most profitably used for mechanistic and predictive purposes.
The effect of U.V.‐light on some components of the nucleic acids. V. Reversibility of “the first irreversible reaction” under special conditions
Authors: Beukers R. , Ijlstra J. , Berends W. 
Published: September 2010

AbstractThe extent to which the extinction of thymine and orotic acid decreases on irradiation by U.V. light depends on the environmental conditions. Successive irradiations in different milieus ultimately lead to a degree of conversion which is wholly determined by the conditions during the last irradiation. Consequently it is possible to revert the substances that seem to have disappeared to the original products.
Studies in polarography IV reduction of manganate at the dropping mercury electrode
Authors: Issa I. M. , Issa R. M. , Hewaidy I. F. 
Published: September 2010

AbstractThe polarography of manganate has been studied in sodium hydroxide solutions as supporting electrolyte, particularly as regards the effects of alkalinity, manganate concentration and the presence of formic acid. At alkalinities less than 1 M NaOH reduction passes to Mn+2 and then to Mn0 along two main waves. In 1 M NaOH reduction yields Mn+3 and then Mn0. Polarograms in 0.1, 0.5 and 1 M alkali can be used for the determination of manganate in 2.5 × 10−4 to 2 × 10−3 M solutions.
The use of ion‐exchangers in detergent analysis, Part II
Authors: Voogt P. 
Published: September 2010

AbstractThe method described is supplementary to and an extension of a method previously described for the analysis of detergents by means of ion‐exchangers.The A.D. acid (i.e., active detergent in acid form) adsorbed on the Dowex‐1, X2, [Ac−] ion‐exchanger can be quantitatively eluted with a solution of sodium acetate. After conversion of the sodium salts into the corresponding acids, the A.D. acid and acetic acid can be separated by ion‐exclusion. Fatty acids are adsorbed on Dowex‐1, X2, [OH−] and can be eluted with KOH‐solution.Experiments with dodecylsulphuric acid, dodecylsulphonic acid and acyltaurines are described, but it is possible that the ion‐exclusion technique can be extended to other detergents.Any urea present is adsorbed in alcoholic medium on Dowex‐50, X8, [H+].
Preparation and some properties of ISbCl8 and IAlCl6
Authors: Vonk C. G. , Wiebenga E. H. 
Published: September 2010

AbstractThe preparation of the new compounds ISbCl8 (m.p. 83.5°C, d = 3.00 ± 0.02) and IAlCl6 (m.p. 105°C, d = 2.64 ± 0.02) is described. The compounds react readily with water and decompose on heating.ISbCl8 does not show any appreciable ionization in the fused state or when dissolved in liquid SO2. When dissolved in CCl4, it is probably completely dissociated into ICl, Cl2, and SbCl5.
Investigations on herbicides II: 2‐Alkyloxy‐ and 2‐aryloxy ‐4,6‐dichloro‐1,3,5‐triazines 2‐Alkylthio‐ and 2‐arylthio‐4,6‐dichloro‐1,3,5‐triazines
Authors: Koopman H. , Uhlenbroek J. H. , Haeck H. H. , Daams J. , Koopmans M. J. 
Published: September 2010

AbstractAn improved synthesis of 4,6‐dichloro‐2‐phenoxy‐1,3,5,‐triazine from cyanuric chloride and phenol in the presence of collidine (2,4,6‐trimethyl‐pyridine) induced us to investigate the scope and limitation of the substitution of one chlorine atom in cyanuric chloride and the influence of the base used as an acid acceptor. Phenols, thiophenols, alcohols, thiols and oximes generally reacted with cyanuric chloride in the presence of collidine giving good yields of the corresponding substitution derivatives. The herbicidal and fungicidal properties of the compounds are dealt with and are briefly discussed. The influence of the alkyl or aryl side chain on the biological activity was determined. For this reason some derivatives mentioned in the literature were included for comparison in our biological tests.