bluuebunny/crossref_metadata_2025 huggingface dataset:
The temperature variation of orthobaric density difference in liquid‐vapour systems. II. Water and deuterium oxide
Authors: Costello J. M. , Bowden S. T.
Published: September 2010

The density of deuterium oxide has been determined over the range 20‐200° by means of a sealed‐ dilatometer. The densities above the boiling point are found to be higher than those reported by previous workers.

The applicability of the Verschaffelt equation to ascociated systems of the water type has been examined, and it is shown that the exponent has different values for ranges of temperature below and above the boiling point, and is substantially lower than that found for a normal liquid.
Quantitative determination of antioxidants, after chromatographic separation on completely acetylated filter paper. III. Determination of 1. ρ‐(ρ′‐tolylsulphonylamino)phenyl‐ρ‐toluidine; 2. di‐o‐tolylethylenediamine; 3. hydroquinone monobenzyl ether
Authors: Zijp J. W. H.
Published: September 2010

Methods are described in this paper for the quantitative determination of three antioxidants in vulcanised rubber. The antioxidants are extracted from the rubber compound, separated by partition chromatography on completely acetylated filter paper and determined colorimetrically by appropriate colour reactions.

ρ‐(ρ′‐Tolylsulphonylamino)phenyl‐ρ‐toluidine is oxidised by means of a substituted benzoylperoxide. Both the other antioxidants are coupled with diazotized sulphanilic acid.
Ionylamines I: Synthesis of di‐ and tetra‐hydro‐α‐ and ‐β‐ionylamines and their spasmolytic action
Authors: Kralt T. , Moed H. D. , van Dijk J.
Published: September 2010

The synthesis and properties of amines and quaternary ammonium compounds with the C‐skeleton of ionone and C18‐ketone are described. The spasmolytic activities of the compounds were determined.

The results are discussed and it is concluded that these series of amines show a high musculotropic spasmolytic activity. The relationship between the chemical structure and the spasmolytic activity in these series of amines is fairly clear and regular.
Foam stability: Part. II. Gas diffusion in foams
Authors: de Vries A. J.
Published: September 2010

Pressure differences between foam bubbles of unequal size are the cause of gas transfer from small to larger bubbles. The rate at which the small bubbles decrease in size is calculated as a function of the radius of the bubbles, the surface tension of the liquid and the thickness and permeability of the liquid lamellae between the bubbles. The calculation is based on the assumption that the pressure difference between a small and an adjacent large bubble is dependent only, to a first approximation, on the radius of the smaller bubble.

Values of the average lamella thickness calculated by means of the derived rate equation from the observed rate of shrinking of small bubbles in various foams, are of the right order of magnitude, if it is supposed that the permeability of the lamellae is determined by the solubility and the diffusion constant of the gas in the liquid.

The rate equation enables the number of bubbles per unit volume of foam to be expressed as a function of time if the initial bubble size frequency distribution is known. It is shown that the bubble size distribution function can be calculated from the bubble sizes observed in the plane of contact between the foam and the glass wall of a container. An experimental method of determining the number and sizes of the bubbles in this plane is described.
On the conversion of kojic acid to 5‐hydroxypipecolic acid, a natural imino‐acid
Authors: Beyerman H. C.
Published: September 2010

5‐Hydroxypipecolic acid has recently been found in several plants. A practical synthesis of this acid seemed desirable. In this paper a convenient conversion of kojic acid to 5‐hydroxypipecolic acid and its diastereoisomer is described.
Synthesis of stearoylamino‐acids
Authors: Zeelen F. J. , Havinga E.
Published: September 2010

A series of stearoylamino‐acids was synthesized by condensing stearoyl chloride with the esters of the amino‐acids in a two phase system, one of chloroform and one of an aqueous solution of K2CO3 or KHCO3, followed by saponification of the stearoylamino‐acid esters.
Foam stability: Part III. Spontaneous foam destabilization resulting from gas diffusion
Authors: de Vries A. J.
Published: September 2010

Bubble size frequency distributions in foamed Tee‐pol solutions, oil‐in‐water emulsions and Hevea rubber latex have been calculated from the observed bubble sizes in the plane of contact between the foam and the glass wall of the container. The bubble size distribution in these foams can be satisfactorily described by the same mathematical expression containing one adjustable parameter.

Using this expression for the distribution function, a relation is derived between the total number of bubbles per unit area of the cross‐section and the age of the foam, assuming that the disappearance of the small bubbles is caused only by transfer of gas to larger bubbles. With the aid of the derived relationship the average thickness of the liquid lamellae in a number of foams is calculated from the observed rate of decrease in the number of bubbles in the front layer.

The calculated values of the average film thickness are of the same order of magnitude as those calculated directly from the observed bubble size distribution and the liquid content of the foam. Additional evidence of the proposed destabilization mechanism is obtained from experiments, in which the nature of the gaseous phase was varied and from comparison of the rate of decrease in the number of bubbles with the rate of shrinking of individual bubbles.
Dissociation and electrical conductance of the sodium, potassium, calcium and magnesium salts of haemoglobin
Authors: van Os G. A. J. , Möller W.
Published: September 2010

The interaction of Na, K, Ca and Mg with bovine and human haemoglobin has been investigated by means of conductivity measurements. It has been found that in unbuffered solutions at pH = 7.8 and protein concentrations from 2.5‐4%, Na, K, Ca and Mg, are not bound by haemoglobin.
Quantitative investigation of the nitration of benzonitrile
Authors: Wibaut J. P. , van Strik R.
Published: September 2010

The nitration of benzonitrile has been investigated at 0°. −9° and −20° and the ratios of the isomers produced, determined quantitatively. The varation of this ratio with variation in the temperature can be represented by Scheffer's formula.

Attempts to introduce a second nitro group into p‐nitrobenzonitrile were unsuccessful, this compound being extremely resistant towards nitrating agents.
Studies on vitamin‐D and related compounds VIII: The photoisomerisations of provitamin‐D and its irriadation products. Short communication
Authors: Rappoldt M. P. , Buisman J. A. Keverling , Havinga E.
Published: September 2010

Results of kinetic investigations and measurements of quantum yields are reported, which cannot be explained by the most simple scheme imaginable for the photochemical interconversions of provitamin‐D and its isomers. At least two excited transitory species have to be assumed.

More experimental data will be needed before a decision can be made in favour of one or other of the hypothetical, more complicated, pathways.
Synthesis and reactivity of N‐(4‐pyridonyl)oxyacetic acid
Authors: Bojarska‐Dahlig H. N. , den Hertog H. J.
Published: September 2010

N‐(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

Volumetric 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

Adsorption 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

Une 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.
An outline of enzyme induction
Authors: Monod Jacques
Published: September 2010

A possible model of the mechanism of enzyme induction is presented and discussed in the light of present experimental knowledge. The central assumption in this model is that induction brings about the conversion of an enzyme‐precursor resulting in liberation and activation of a preexisting enzyme‐forming system.
Protein synthesis in mammalian cells with particular reference to antibody formation
Authors: Askonas Brigitte A.
Published: September 2010

Recent 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

Evidence 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

2‐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

The 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

Yeast 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

The 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

Measurements 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

Ethyl 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

The 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

The 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).

.
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

Les 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

Values 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

Researches 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

Phosphonic 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

Tetrazole 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.
Two experiments in one run with the analytical ultracentrifuge
Authors: Bon W. F.
Published: September 2010

With a polaroid filter placed on the upper quartz disk of each of two boundary forming cells and an analysing filter between rotor and camera it is possible to get perfectly separated images of the boundaries in each cell during the experiment.
The condensation of rhodanine and derivatives with polycyclic aromatic aldehydes
Authors: Allan F. J. , Allan G. G.
Published: September 2010

The 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

The 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

Recently 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

The 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

The 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.
Synthesis and pharmacological properties of salicylamides
Authors: Kralt T. , Moed H. D. , Ariens E. J. , Hendriksen Th. W. J.
Published: September 2010

The synthesis of a series of N‐substituted salicylamides (Tables I, 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

The 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

The 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.
Chemistry of acetylenic ethers XXXVII. Some new acetylenic ethers
Authors: Nooi J. R. , Arens J. F.
Published: September 2010

A number of 1‐methoxy‐1‐alkynes and some other acetylenic ethers were prepared using the procedure outlined in the reaction scheme. The yields were satisfactory.
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

With 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.
A new synthesis of 2,6‐dibromopyridine‐N‐oxide
Authors: Evans R. F. , van Ammers M. , den Hertog H. J.
Published: September 2010

In contrast to other organic peracids, peroxytrifluoroacetic acid smoothly oxidizes 2,6‐dibromopyridine to its N‐oxide in good yield.
Phloroglucinol from picryl chloride
Authors: Heertjes P. M.
Published: September 2010

The 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.
The acetolysis of 4‐phenyl‐1,3‐dioxan. A new synthesis of cinnamyl esters
Authors: Heslinga A.
Published: September 2010

The synthesis of 3‐phenyl‐2‐oxa‐1,5‐pentanediol diacetate is given. This compound offers a new route to the preparation of cinnamyl esters.
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

The results are presented of investigations on preparing dihydrotachysterol2 from dihydrovitamins D2‐I and D2‐II.
Steric effects on mesomerism. XX. The dipole moments of some nitrobenzene derivatives
Authors: Kofod H. , Sutton L. E. , Verkade P. E. , Wepster B. M.
Published: September 2010

The dipole moments of some ortho‐substituted nitrobenzenes are discussed.
A simple re‐evaluation of the hammett ϱσ relation
Authors: van Bekkum H. , Verkade P. E. , Wepster B. M.
Published: September 2010

Starting 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

The 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

The 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

The 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

The 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

An 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.
Interaction between dimethylpyruvic acid and biotin with a mould
Authors: Brouwer J. N. , Ylstra J. , Berends W.
Published: September 2010

The separation of dimethylpyruvic acid observed by Katsuki from the mould, Piricularia oryzae, with a deficiency of biotin, has been investigated. The formation of dimethylpyruvic acid does not depend on aeration. Addition of biotin leads to the absorption of dimethylpyruvic acid so that there is possibly a connection between the separation of this acid and the function of biotin.

A method for the determination of dimethylpyruvic acid in the presence of pyruvic acid and α‐ketoglutaric acid has been worked out.
Synthese de Cortisol Tritie
Authors: Osinski P. , Vanderhaeghe H.
Published: September 2010

Partial reduction of prednisolone yields a mixture containing, besides the starting material, Cortisol, pregn‐1‐en‐11β, 17α, 21‐triol‐3,20‐dione and di‐hydrocortisol. The separation of these products is described. Using tritium gas, the same radioactive steroids with a high specific activity were prepared. The specific activity of cortisol‐1,2‐3H was 835 mc/mmole. The isotopic stability of the products has been examined and found satisfactory. Corticostérone‐1,2‐3H, cortisone‐1,2‐3H and androst‐4‐ène‐11β‐ol‐3,17‐dione of high specific activity have been prepared from cortisol‐1,2‐3H.
The stepwise degradation of “trismethylene‐trinitrobenzene”: Nucleophilic aromatic addition II
Authors: de Boer Th. J. , van Velzen J. C.
Published: September 2010

“Trismethylenetrinitrobenzene” (I) has been degraded in five steps to cis‐ and trans‐nitrocyclopropanecarboxylic acid (IX and X), via the sequence, depicted in chart 1: I (C9H9N3O6 → II (C8H8N2O8) → V (C7H8N2O6) → VI (C7H8N2O7) → VII (C5H5NO6) → IX and X (C4H6NO4).

II is a dicyclopropanedicarboxylic acid which very easily loses one molecule of CO2, to give no longer a carboxylic acid, but a lactone V.

The unusual “decarboxylation‐lactonisation” process involves rupture of a CC bond in one three‐membered ring, and lactonisation with the carboxyl group attached to the unbroken three‐membered ring.

The lactone V can be oxidised further to the keto acid VI and the nitro‐cyclopropanedicarboxylic acid VII. The latter upon decarboxylation affords IX and X. The structures of these hitherto all unknown degradation products are established by chemical, physical and spectroscopical (including NMR) evidence, thus lending support to the presence of two cyclopropane rings in “trismethylenetrinitrobenzene”.
Über Muscaridin
Authors: Kögl F. , Salemink C. A. , Schuller P. L.
Published: September 2010

The present communication gives a preliminary description of the isolation of a new alkaloid from Amanita muscaria L. besides muscarin and acetylcholin. The constitution of this base, called muscaridin, is established as the quaternary trimethylammonium salt of 6 amino‐2,3‐dihydroxy‐hexan.
Physical properties of organic thiones. Part II. Electronic absorption spectra of compounds containing the thiocarbonyl group
Authors: Janssen M. J.
Published: September 2010

Electronic absorption spectra of compounds containing a thiocarbonyl group bound to carbon, sulphur or oxygen are reported. The spectra were taken, whenever possible, in cyclohexane, ethanol and concentrated sulphuric acid.

The bands are compared with those of nitrogen‐containing thiones and an empirical assignment of the different types of bands is given.
Note on the preparation of 3‐hydroxy‐5‐hydroxymethyl‐2,4‐dimethyl‐pyridine: (4‐Desoxyadermine)
Authors: Wibaut J. P. , Uhlenbroek J. H. , Kooyman E. C. , Kettenes D. K.
Published: September 2010

The intermediate steps in the synthesis of 4‐desoxy‐adermine described some time ago

H. M. van Wagtendonk and J. P. Wibaut, Rec. trav. chim. 61, 728 (1942).

have been improved upon, particularly the conversion of the last intermediate 3‐amino‐2,4‐dimethyl‐5‐methyl‐amino‐pyridine (VII) to desoxyadermine. As a result of these improvements, desoxyadermine can now be synthesized in an overall yield of 15%, based on the starting materials acetyl acetone and cyanoacetamide.
Propriétés Chimiques dans L'Eutectique LiCl‐KCl Fondu
Authors: Delarue Guy
Published: September 2010

Nous avons étudié qualitativement la solubilité des oxydes et des sulfures métalliques dans l'eutectique LiCl‐KCl fondu. Les courbes intensité‐potentiel montrent que les solutions obtenues contiennent respectivement les particules O2− et S2− que l'on peut oxyder chimiquement ou électrochimiquement.
Solubility and mobility of aromatic hydrocarbons in pyridine
Authors: Fortuin J. M. H. , Dormans H. N. M. , van Krevelen D. W.
Published: September 2010

The solubilities of some aromatic hydrocarbons in pyridine have been measured. The entropies of fusion derived from these measurements agree qualitatively with the values which can be calculated, if it is assumed that their molecules obtain one rotational and three translational degrees of freedom when melting occurs.
Phosphatidic acids and derivatives: X. Diastereoisomerism with O,N,N‐tribenzyl‐glycerol‐α‐kephalins
Authors: Hoefnagel M. A. , Stegerhoek L. J. , Verkade P. E.
Published: September 2010

O,N,N‐tribenzyl‐glycerol‐α‐kephalins have been obtained in two diastereoisomeric forms. Upon hydrogenolysis the two isomers give the same kephalin.

This diastereoisomerism, due to the presence of an asymmetric carbon atom and an asymmetric phosphorus atom, is discussed in some detail.
The determination of uranium and of thorium in their compounds by gamma radiation measurements
Authors: Korvezee A. E.
Published: September 2010

Radiometric determination of uranium and of thorium in their compounds can be effected in principle by gamma counting with a scintillation spectrometer.

The complications that arise when the radioactive equilibrium with the daughter products in the samples to be analysed is not established, are discussed.
The calibration of millivoltmeters and thermoelements and the combination of the two
Authors: Meyer G. , Oosterom J. F.
Published: September 2010

A calibration method for thermoelements combined with millivolt‐meters is described, which yields an accurate result in a comparatively short time. The method has been described for the use of Pt‐Pt Rh. thermoelements; it can naturally be employed for other thermoelements as well.
Graphical representation of composition and temperature of a binary liquid in a rectifying distillation column
Authors: Smittenberg J.
Published: September 2010

The definition of a “theoretical plate” of a rectifying distillation column is discussed and graphs are constructed indicating composition and temperature of liquid and vapour as a function of column height both at infinite and at finite reflux ratios.
The alkaline hydrolysis of oxazolidinediones‐2,4
Authors: Rekker R. F. , Nauta W. Th.
Published: September 2010

Controversial structures have been assigned 1,2 to the nitrogen‐containing carboxylic acid which is one of the products formed on hydrolysis of N‐substituted oxazolidinediones‐2,4. The present publication solves the problem in favour of our previous suggestions.
Study of the reactions between titanium tetrachloride and ethylaluminium compounds in hydrocarbon solution: I. Formation and properties of brown precipitates
Authors: Arlman E. J. , de Jong J. R.
Published: September 2010

The reaction between TiCl4 and AlEt3, AlEt2Cl and AlEtCl2 at 80°C in isooctane was investigated for those Al/Ti ratios at which brown precipitates are formed. In these reactions Ti(IV) is not reduced beyond Ti(III). The extent of reduction was determined by oxidimetry and colorimetry; the two methods gave concordant results.

Among the gaseous reaction products ethyl chloride was determined quantitatively by gas chromatography. Its formation is ascribed to a secondary reaction:

The C2H5 radicals are formed in the main reaction in which the ethyl‐aluminium chlorides are converted into AlCl3 and the triethylaluminium into Al2EtCl5.

By means of the conversions indicated above the relation between the percentage of reduction of Ti(IV) to Ti(III) and the Al/Ti ratio is accounted for quantitatively. The precipitates formed in the system AlEt3/TiCl4 were found to consist mainly of the brown modification of TiCl3 in which about one sixth of the titanium is replaced by aluminium.
Mechanism of reactions of unsaturated ethers and thioethers. I: Add catalyzed addition of water to acetylenic thioethers
Authors: Drenth W. , Hogeveen H.
Published: September 2010

The acid catalyzed addition of water to ethylthioethyne has been studied in aqueous solution. The reaction is general acid catalyzed and it is faster in H2O than in D2O. Substitution of a tertiary butyl group for the ethyl group results in a rate enhancement. The entropies of activation ΔS≠ for the hydration of ethylthioethyne and tertiary butylthioethyne are ‐ 6.1 and ‐ 0.6 cal. mole−1, deg.−1, respectively. These facts strongly suggest that protonation of the alkylthioethyne is the rate controlling step of the reaction.
Studies on vitamin D and related compounds XIV Investigations on sterols XVII: The photoisomerization of pre‐ergocalciferol and tachysterol2
Authors: Rappoldt M. P.
Published: September 2010

The quantum yields of the isomerizations of pre‐ergocalciferol and tachysterol2 in ether at 20° under the influence of ultraviolet light of 2537 Å were found to be 0.49 and 0.11 respectively. Ergosterol is not formed from tachysterol2 during irradiation but originates exclusively from pre‐ergocalciferol. The origin of lumisterol2 is somewhat less certain; it seems to be formed from tachysterol2.
Synthesis of a tyrosine “homologue” of lysine‐vasotocin
Authors: Beyerman H. C. , Bontekoe J. S.
Published: September 2010

The synthesis is described of the protected linear decapeptide: N‐benzyloxycarbonyl‐S‐benzyl‐L‐cysteinyl‐L‐tyrosyl‐L‐tyrosyl‐L‐isoleucyl‐L‐glutaminyl‐L‐asparaginyl‐S‐benzyl‐L‐cysteinyl‐L‐prolyl‐Ne‐tosyl‐L‐lysylglycineamide (II, Fig. 2).

Removal of the blocking groups from II, followed by oxidation, yielded a preparation assumed to contain a “homologue” of lysine‐vasotocin with two consecutive molecules of tyrosine instead of one (Fig. 1, n = 2).
Mechanism of reactions of unsaturated ethers and thioethers II: Dipole moment and charge shift in acetylenic ethers
Authors: Drenth W. , Hekkert G. L. , Zwanenburg B. G.
Published: September 2010

Electric dipole moments of the following compounds have been measured in benzene solution: C2H5OC2H5, H2CCHOC2H5, HC ≡ COC2H5, H3CC ≡ COC2H5, HC ≡ COCH3 and H3CC ≡ COCH3. The charge shift, caused by resonance, in HC ≡ COC2H5 and HC ≡ COCH3 amounts to approximately 0.11 e.
Synthesis of an analogue of lysine‐vasopressin, with phenylalanine “replaced” by two consecutive tyrosyl radicals
Authors: Beyerman H. C. , Bontekoe J. S.
Published: September 2010

A synthesis is described of the protected linear decapeptide: N‐benzyloxycarbonyl‐S‐benzyl‐L‐cysteinyl‐L‐tyrosyl‐L‐tyrosyl‐L‐tyrosyl‐L‐glutaminyl‐L‐asparaginyl‐S‐benzyl‐L‐cysteinyl‐L‐prolyl‐Ne‐p‐toluene‐sulphonyl‐L‐lysylglycineamide (VI) in analytically pure form.

Removal of the blocking groups from VI, followed by cyclization through oxidation, yielded a preparation which was assumed to contain an analogue of lysine‐vasopressin, with L‐phenylalanine “replaced” by two consecutive L‐tyrosyl radicals.

This synthesis was performed in connection with our previous studies on the relation between chemical structure and biological activity in the oxytocin and vasopressin field.
The chemistry of the N‐alkylaldimines. II. The reaction of N‐propylpropanaldimine with acid chlorides
Authors: Breederveld H.
Published: September 2010

N‐Propylpropanaldimine adds on acid chlorides with formation of the corresponding N(1‐chloropropyl)‐N‐propylamides, which on heating split off hydrochloric acid to yield the N(1‐propenyl)‐N‐propyl derivatives as the final products.

N(1‐Propenyl)‐N‐propylacetamide, N(1‐propenyl)‐N‐propylbenzamide, diethylamino‐(1‐propenylpropylamino)‐dichlorosilane and dichlorophosphor‐N(1‐propenyl)‐N‐propylamidic acid have been prepared by this method.
Interpretation of cell responses in the laplace transformed state as an approach to the study on electrode kinetics
Authors: Wijnen M. D.
Published: September 2010

It is proposed to interpret cell responses in the Laplace transformed state. Information concerning the electrode reaction can then be obtained from the measured response on the basis of the derived response, both responses being in the transformed state.

Advantages of the approach are: (a) interpretation of a measured response may be simpler and more exact in the transformed state than in the non‐transformed state; (b) the tedious inverse transformation of a derived relationship is omitted.

The approach is illustrated on two cases of the so‐called potential‐step electrolysis.

Methods for the experimental Laplace transformation of a measured response are outlined.
A new synthesis of 3‐aryl‐4‐hydroxycoumarins
Authors: van Zanten B. , Th. Brinkman U. A. , Th. Nauta W.
Published: September 2010

In the course of an investigation into the synthesis and properties of 3‐aryl‐4‐hydroxycoumarins a new direct synthesis of these compounds was found. In an acid medium 4‐hydroxycoumarin can be coupled directly to a diazotized aniline to form the desired 4‐hydroxycoumarin derivative.
Thermal quantities of cycloparaffins: Part IV. Heats of combustion of cycloparaffins with 10‐17 C atoms
Authors: Coops J. , van Kamp H. , Lambregts W. A. , Visser B. J. , Dekker H.
Published: September 2010

The heats of combustion at 25° of purified samples of the cycloparaffins having from 10 to 17 C atoms, have been measured. A brief description is given of the preparation and purification of the samples. The enthalpies ‐ ΔHR, given in the table below refer to the reactions:

at 25° and 1 atm.

magnified image

A discussion will be given in a later paper.
A synthesis of 1‐hydroxy‐8‐methoxyanthraquinone‐3‐carboxylic acid
Authors: Bellaart A. C. , Koningsberger C.
Published: September 2010

The structure of 1‐hydroxy‐8‐methoxyanthraquinone‐3‐carboxylic acid, previously obtained by the action of dimethyl sulphate on the sodium salt of synthesized rhein monoglucoside, has now been confirmed by synthesis.
Chemistry of acetylenic ethers XLVII: Preparation of α‐ketols from ethoxyethynylcarbinols
Authors: Weiland J. H. Sperna , Arens J. F.
Published: September 2010

A method is described for converting ethoxyethynylcarbinols I into α‐ketols V, via the intermediate products II to IV inclusive. The synthesis occurs stereospecifically and, starting from the ethoxy‐ethynylcarbinol VII, derived from 3β‐acetoxyandrost‐5‐en‐17‐one VI, affords almost exclusively 3β,21‐dihydroxypregn‐5‐en‐20‐one XI in about 50% yield.
Aromatic sulphonation II: Orientation in the sulphonation of toluene
Authors: Vollbracht L. , Cerfontain H. , Sixma F. L. J.
Published: September 2010

The isomer distribution for the homogeneous sulphonation of toluene at 25.0° in 82.3 ± 0.3 wt‐% aqueous sulphuric acid has been determined by the inverse isotope dilution method as 65.1% para. 2.9% meta and 32.0% ortho. Combining these data with the relative reactivity of toluene to benzene (kt/kb) = 66.1) 1 the partial rate factors were calculated as fpMe 258; fmMe 5.7 and foMe 63.4.