bluuebunny/crossref_metadata_2025_split huggingface dataset:
The halogenation of aromatics: Part I. Gas phase chlorination of chlorobenzene
Authors: Engelsma J. W. , Kooyman E. C. , van der Bij J. R. 
Published: September 2010

AbstractThe gas phase chlorination of chlorobenzene has been investigated at temperatures between 275 and 500° C, using empty glass reactor tubes. Intake ratios of chlorine and aromatics were 1/2 and nitrogen was used as a diluent. Contact times were 1/2‐1 minute.Dichlorobenzenes were obtained in high yields based on chlorobenzene converted. Carbon formation was negligible at temperatures below 465° C; no indications as to formation of by‐products were obtained.Whereas chlorine conversions increased from 2 to 70% over the temperature range studied, isomer compositions of dichlorobenzenes showed little variation, viz. 68‐62% meta, about 24% para and 8‐13% ortho, the first‐mentioned figures applying at the lower reaction temperatures.Meta/para ratios were, therefore, always appreciably higher than 2. A transition of the substitution type, such as has been observed in some cases by Wibaut and his coworkers1), did not occur.
On the absolute configuration of sedamine and sedridine: (Preliminary communication)
Authors: Beyerman H. C. , Eenshuistra J. , Eveleens W. 
Published: September 2010

AbstractThe resolution of (±)‐allo‐sedamine into its optical components and of (±)‐sedridine yielding (+)‐sedridine is recorded.An alkaloid of undetermined constitution previously obtained from Lobelia inflata L. by H. Wieland et al. seems identical with one of the enantiomorphs of (±)‐allo‐sedamine.The determination of the absolute configuration of the piperidine part of the alkaloids sedamine, allo‐sedamine and sedridine is described. The results agree with the conception of the biosynthesis of (‐) ‐sedamine and (+)‐sedridine from L‐amino‐acids.
Hydrocarbures polycycliques aromatiques. V.) La réaction d'Elbs chez les dibenzoyl‐2,7‐diméthyl‐naphtalènes
Authors: Buu‐Hoï N. P. , Lavit Denise 
Published: September 2010

AbstractIl est démontré que, dans la réaction de Friedel‐Crafts entre 2 mol. de chlorure de benzoyle et une mol. de 2,7‐diméthylnaphtalène, il se forme trois dicétones, et non une seule comme l'indiquait la littérature; on étudie le comportement de chacune de ces dicétones dans la réaction de pyrolyse d'Elbs, et il est montré que l'une des dicétones le naphto[2,3a]‐naphtacène, une autre fournissant un composé oxygéné, probablement dérivé de l'anthra[1,2‐a]anthracène, et la troisième dicétone n'ayant fourni aucun produit défini. Il est montré que le naphto[2,3‐a] naphtacène donne un aldéhyde par formylation (probablement le 9‐formyl‐naphto[2,3‐a] naphtacène.
Studies in polarography: III. Reduction of permanganate in presence of telluric acid at the dropping electrode
Authors: Issa I. M. , Khalafalla S. E. , Issa R. M. 
Published: September 2010

AbstractThe polarography of alkaline permanganate solutions in presence of telluric acid has been studied. It is shown that reduction of Mn+7 passes through an ill‐defined zero wave to Mn+3. This latter is then reduced to Mn+2 along a sloping wave. The waves of telluric acid and the Mn+2‐Mn are vitiated by the precipitation of manganous tellurate. The lowering of id of the Mn+7/Mn+2 wave and the early reduction of telluric acid indicates the formation of a double salt between permanganate (A) and tellurate (B) of the formula AB2.
The Raman and infra‐red spectra of some compounds (iH7C3O)2PXO
Authors: Maarsen J. W. , Smit M. C. , Matze J. 
Published: September 2010

AbstractThe Raman and infra‐red spectra of a series of compounds, represented by the general formula (iH7C3O)2PXO, in which X may be H, CH3, OH, O‐iC3H7, F, Cl, NH2, NHCH3, and N(CH3)2, have been investigated.It was shown that there exist at least two frequencies for P‐O stretching,viz, symmetrical and asymmetrical. To the symmetrical stretching has been assigned a frequency at 720‐750 cm−1, which is very strong in Raman. To the asymmetrical stretching belongs a frequency at 973‐1030 cm−1, very strong in infra‐red, but weak or even missing in Raman.Other frequencies of the compounds could be interpreted in accordance with assignments given in the literature.
A relationship between dipole moments and the Hammett equation
Authors: van Beek L. K. H. 
Published: September 2010

AbstractAn empirical formula is proposed relating the constant ω in the Hammett equation to the observed dipole moment of a compound (para‐ or meta‐ C6H4XY). This relationship is checked by using data which have been cited in the literature. These data appear to confirm the proposed linear behaviour when log μ is plotted against σ.
Determination and adjustment of the activity of adsorbents for chromatography and of the eluting power of elution solvents by means of the “shake test”: (Analysis of fat soluble vitamins III))
Authors: Keuning K. J. , van Dijk G. J. , de Vries M. J. Wiggers 
Published: September 2010

AbstractAdjustment of the activity of adsorbents for chromatographic use (e.g. Al2O3 or CaHPO4 by the controlled take‐up of water) can be done in a reproducible and accurate manner with the aid of the “shake‐test”. It consists in shaking a weighed sample (2 g) of the adsorbent with a measured volume (10 ml) of the elution solvent in which the substance to be eluted (e.g. 1000 I.U. of vitamin‐A) has been dissolved. The activity is suitable if about 50% is adsorbed. The following operations can be performed by means of the shake test.(1) determination of the activity of adsorbents; (2) adjustment of the activity of an adsorbent; (3) replacement of an adsorbent by another of the same activity; (4) finding the correct composition of the elution solvent; (5) replacement of one solvent by another of equal eluting power.The shake test has been developed for a 10 cm column containing 10 g of Al2O3; 40 % adsorption is satisfactory for rapid elution. If slower elution is wanted, or if thinner columns (containing less adsorbent) are employed, the percentage adsorption must be larger than 40%, up to 60%. The shake test is a purely practical test; no theoretical significance can be attached to it.
The vibrational spectrum and force constants of P4S3
Authors: Gerding H. , Maarsen J. W. , Nobel P. Chr. 
Published: September 2010

AbstractThe Raman spectra of P4S3 in the solid and molten states and in solution in CS2 have been determined.It appeared impossible to obtain reliable quantitative depolarization factors; the assignment was therefore based on the visually estimated state of polarization.The spectra in CS2 solution contained several unexplained frequencies, much higher than was to be expected.Force constants for the P‐S and P‐P bonds have been calculated, on the basis of the C3v symmetry, assumed for the molecule.The values found are distinctly lower than those calculated with Badger's or Gordy's formulae from known bond distances. The calculations in the main support the structure for P4S3 determined by electron diffraction and X‐ray analysis.
The phosphorylation of thiamine in the livers of normal and alloxan‐diabetic rats
Authors: Vincent J. E. 
Published: September 2010

AbstractA procedure for the separation and isolation of thiamine and cocarboxylase from liver extracts has been described using repeated chromatography on Amberlite IRC‐50 columns.The phosphorylation of thiamine in normal and alloxan‐diabetic rats was investigated with the aid of thiamine‐35S. No difference in the rate of formation of radioactive cocarboxylase in the liver could be observed at different times after the intraperitoneal injection of thiamine‐35S. We conclude that the phosphorylation of thiamine is not impaired in alloxan‐diabetic rats.
The electronic spectra of aromatic hydrocarbon anions
Authors: de Boer E. , Weissman S. I. 
Published: September 2010

AbstractThe electronic spectra of several hydrocarbon anions have been measured. A comparison is given between these spectra and the spectra obtained by Hoytink et al.2). It appeared that the positions of the absorption bands are only shifted about 0.2 kK to lower wavelengths, using potassium instead of sodium as reducing agent.
Hyperconjugation and induction in 1‐methylpolyenyl negative ions
Authors: Bouman N. , Hoijtink G. J. 
Published: September 2010

AbstractThe influence of 1‐methyl substitution on the charge distribution in the allyl, pentadienyl and heptatrienyl negative ion has been investigated.It appears that the results of the theoretical computations are qualitatively the same for hyperconjugation and for induction.
A general theoretical approach to the course of chemical reduction, electrochemical reduction and catalytic hydrogenation of hydrocarbons with conjugated double bonds
Authors: Hoijtink G. J. 
Published: September 2010

AbstractThe course of reduction and hydrogenation of various conjugated hydrocarbons has been investigated theoretically on the basis of a general ionic mechanism. The structures of the partial and final reduction products have been predicted from the charge distribution in the intermediately formed negative ions under the influence of a homogeneous electric field, the magnitude of which depends on the conditions of the experiment. The predicted results prove to be in good agreement with the experimental data. It appears that the main contribution to the electric polarisation of the intermediately formed ions is due to the electric field in the electrical double layer at the “electrode” surface.The reduction and hydrogenation of the following hydrocarbons has been considered: benzene, naphthalene, anthracene, phenanthrene, pyrene, triphenylene, 1,2‐benzanthracene, biphenyl, terphenyl and quaterphenyl. The good agreement between the results of the present theory and the experimental data is a strong argument in favour of the supposition that in catalytic hydrogenation the primary reaction involves the addition of two electrons to the hydrocarbon molecule.
Synthesis of peptides by means of ethyl α‐chlorovinyl ether and α, α‐dichlorodiethyl ether
Authors: Heslinga L. , Arens J. F. 
Published: September 2010

AbstractEthyl α‐chlorovinyl ether IV and α, α‐dichlorodiethyl ether V can be used for the synthesis of peptides. The reactions are performed by refluxing a mixture of an acylamino acid I, an amino acid ester‐hydrochloride II and one of the chlorinated ethers IV or V in ethyl acetate. Optically pure acyl peptide‐esters VII are obtained. The method has been applied mostly for the preparation of acyl dipeptide‐esters, but higher peptides have also been obtained. Acylamino acid chlorides VI are most probably intermediates.
The physical meaning of the constants in Smittenberg's formula
Authors: Fortuin J. M. H. 
Published: September 2010

AbstractA relation between the physical constants and the number of methylene groups per molecule of hydrocarbons belonging to a homologous series is derived. The formula obtained is of the same type as the emperical one proposed by Smittenberg. The physical meanings of the constants in this formula are indicated. Reduced values of physical constants are introduced. The relation between these values and the number of methylene groups per molecule is nearly linear.
Investigations on organic insecticides II. Preparation and acaricidal properties of substituted diphenylsulphones, diphenylsulphides and diphenylsulphoxides
Authors: Huisman H. O. , Uhlenbroek J. H. , Meltzer J. 
Published: September 2010

AbstractThe preparation and acaricidal properties of a number of variously substituted diphenylsulphones, diphenylsulphides and diphenylsulphoxides are described. A few of them possess strong acaricidal properties. The most outsanding proved to be 2,4,5,4′‐tetrachlorodiphenylsulphone ‐ “Tedion V18” ‐ which combines high activity on all stages, except adult spider mites with total absence of phytocidal side‐effects and toxicity for warm‐blooded animals.
Total synthesis in the steroid series. III: Synthesis of aldosterone
Authors: van der Burg W. J. , van Dorp D. A. , Schindler O. , Siegmann C. M. , Szpilfogel S. A. 
Published: September 2010

AbstractThe transformation of the substituted D‐homoandrostane derivative IV (see preceding paper) into a known aldosterone intermediate is described.
Chemistry of acetylenic ethers XXX. Additions of trichloroacetic acid, its anhydride and its chloride to ethoxyacetylene
Authors: Broekema R. , van der Werf S. , Arens J. F. 
Published: September 2010

AbstractBy adding one equivalent of trichloroacetic acid to ethoxyacetylene (I) an addition product (IIIa) is formed. The reverse procedure if carried out very slowly gives rise to a different compound (VII), which can also be obtained from ethoxyacetylene and trichloroacetic anhydride.Addition of trichloroacetic acid to the substance IIIa produces ethyl acetate and trichloroacetic anhydride. The same substance is formed directly by adding ethoxyacetylene to two equivalents of trichloroacetic acid.Ethoxyacetylene can also add trichloroacetyl chloride, this yields X.These transformations and the reactions performed for establishing the structures of IIIa, VII and X are summarised in a reaction scheme.The addition of one and two moles of hydrogen bromide respectively to ethoxyacetylene yields ethyl α‐bromovinyl ether (XV, X = Br) and α,α‐dibromodiethyl ether (XVI, X = Br).
The viscosity of cis‐ and trans‐decalin
Authors: Boelhouwer C. , Waterman H. I. 
Published: September 2010

AbstractViscosity data on cis‐ and trans‐decalin are discussed in respect to recent investigations on the viscosity‐temperature dependence of liquids. No abnormal behaviour of the viscosity in the temperature range (−30° C to + 180° C) considered was observed.
The action mecanism of actidione
Authors: Latuasan H. E. , Berends W. 
Published: September 2010

AbstractInvestigation of the action mechanism of actidione on yeasts has made it quite clear that yeasts with a high respiratory quotient, i.e. strongly aerobic fermenting, are especially sensitive to actidione. These observations led to attempts to examine whether actidione intervenes in the Embden‐Meyerhof cycle in dormant yeasts. There appears to be a check on the enzyme alcoholdehydrogenase. The enzyme lactic acid‐dehydrogenase from muscle, which also contains DPN as coenzyme, shows exactly the same type of sensitivity. From an examination of the cause of this effect it appears that in vitro glutarimide and succinimide can imitate the action of actidione on these enzymes exactly. Substitution of the imido group completely destroys the activity of these substances. It is shown that it is probably worth while to examine a whole series of glutarimide and succinimide derivatives for fungicidal and anti‐tumour activity.
The structure of solid phosphorus pentabromide
Authors: Gerding H. , Nobel P. C. 
Published: September 2010

AbstractThe Raman frequencies of solid phosphorus pentabromide, excited by the green and yellow mercury lines, are: 72(6), 140(14), 189(0+), 227(26), 367(2−) and 474(9). 72(v2.3), 140(v4,5,6), 227(v1) and 474(v7,8,9) are the fundamental vibrations of the nearly regular tetrahedron ‐formed by the group PBr4+, which together with Br− build up the lattice of solid PBr5.The force constants according to the Urey‐Bradley field are: K1 = 2.19, K2 = 0.18 and γ3 = 0.028 all in 105 dynes/cm. The corresponding values for SiBr4, isoelectronic with PBr4+, are 1.99, 0.12 and 0.11 × 105 dynes/cm.
Nucleic acid metabolism and induced enzyme formation
Authors: Chantrenne H. 
Published: September 2010

AbstractThe relation between nucleic acid metabolism and enzyme formation is discussed in the light of recent results obtained in the author's laboratory. It is pointed out that the inhibition of enzyme synthesis by purine or pyrimidine analogues is probably due to interference with the metabolism of oligonucleotidic compounds, rather than with the formation of specific ribonucleic acid templates. Enzyme induction in resting yeast is accompanied by changes in the physical properties of some ribonucleic acid fractions.
Synthesis and properties of the chlorination products of methyl 4‐amino‐2‐hydroxy‐benzoate. IV
Authors: van der Stelt C. , Reiding D. J. , Nauta W. Th. 
Published: September 2010

AbstractAs described earlier, two isomers with the structure of a methyl 1,3,3,5,5,6‐hexachloro‐4‐chlorimino‐cyclohexanone‐2‐carboxylate‐1 (XXIIIStructural formulae of compounds numbered up to XXXVII are already given in previous publications.
and XIV) were isolated from the reaction mixture, obtained by chlorination of methyl 4‐amino‐2‐hydroxybenzoate in carbon tetrachloride.Now still an other isomer (mp 146–148° C) (XXXIX) was isolated which differs from XXIII and XXIV by a different spatial arrangement of the chlorine atoms attached to carbon atoms 1 and 6.This was proved by conversion of XXXIX into 1,1,2,3,5,5,5‐heptachloro‐3‐carbomethoxy‐pentanone‐4‐carboxylic acid‐1 (XIX).Reaction of XXXIX with methanolic hydrogen chloride yielded the same reaction product as obtained earlier from XXIII and XXIV. This fact makes clear that the ring opening during this reaction does not take place between carbon atoms 2 and 3 as was supposed earlier, but between carbon atoms 1 and 2. The reaction product must therefore be described as a dimethyl 1,1,3,3,4,5,5‐heptachloro‐2‐imino‐1,5‐pentane‐dicarboxylate (XXXIIIA). The consequence of this correction is that also for several other compounds mentioned previously changed structures are proposed.Reaction of XXXIX with an aqueous potassium iodide solution yielded methyl 1,3,5,5,6‐pentachloro‐4‐amino‐cyclohexene‐3‐one‐2‐carboxylate‐1 (XL) which differs from its isomer obtained from XXIII and XXIV by an analogous reaction. Both XXXIX and XL could be converted into methyl‐4‐amino‐3,5‐dichloro‐2‐hydroxy‐benzoate by treatment with stannous chloride.
Synthesis and some physical constants of four isomeric tripropylbenzenes
Authors: Wibaut J. P. , Paulis B. 
Published: September 2010

AbstractThe synthesis is described of four tripropylbenzenes:1,3,5‐triisopropylbenzene,1,2,4‐triisopropylbenzene,1,3,5‐tri‐n‐propylbenzene,1,2,4‐tri‐n‐propylbenzene.Physical constants of these compounds are given.
Electrophoresis of the proteins in the eye lens of calf and cow
Authors: Bon W. F. , Nobel P. C. 
Published: September 2010

Abstractα‐Crystallin from the eye lens of calves has a smaller mobility in agar electrophoresis experiments than α‐crystallin from the eye lens of adult cows. In addition there are other differences between “young” and “adult” α‐crystallin, for which a possible explanation is given.The investigation described in this paper indicates that proteins undergo development during ontogenesis. Therefore the idea of “chemical differentiation” of embryology ought to be extended to the proteins themselves.
Investigations on pyrazine derivatives II. The preparation of pyrazine 2,3,5‐tricarboxylic acid and of pyrazine 2,5‐ and 2,6‐dicarboxylic acids
Authors: Mager H. I. X. , Berends W. 
Published: September 2010

AbstractA satisfactory preparative method for pyrazine tricarboxylic acid has been found in the oxidation of the readily available 2‐(D‐arabo)‐tetrahydroxybutylquinoxaline. Pyrazine tricarboxylic acid is easily decarboxylated to pyrazine 2,5‐ and 2,6‐dicarboxylic acids. In connection with the poor yield obtained in the oxidation of 2,5‐dimethylpyrazine to pyrazine 2.5‐dicarboxylic acid, it is an advantage first of all to convert the starting material into a condensation product with an appropriate aldehyde.
The synthesis of diduryl ketone
Authors: Galenkamp H. , Faber A. C. 
Published: September 2010

AbstractOn repeating the synthesis of diduryl ketone (duryl = 2,3,5,6‐tetramethylphenyl) by means of the Friedel and Crafts reaction it was found that the resulting product is a mixture of isomeric ketones. The main component is duryl 2,3,4,6‐tetramethylphenyl ketone.Diduryl ketone together with two of the possible isomeric ketones can be synthesized by way of the Grignard reaction.
On the reactivity of organophosphorus compounds. I. The alkaline hydrolysis of some dialkyl p‐nitrophenyl phosphates
Authors: Ginjaar L. , Vel S. 
Published: September 2010

AbstractThe alkaline hydrolysis of some dialkyl p‐nitrophenyl phosphates (RO)2P(O)OC6H4NO2, where R = methyl, ethyl, n‐propyl, isopropyl, n‐butyl, isobutyl and sec‐butyl is described. The effects of α‐, β‐ and γ‐substitution on reactivity as expressed in ΔH* and ΔS* are discussed.
Chemical studies on insecticides VIII: Ultraviolet spectra and opposing resonance in phosphate esters
Authors: Gersmann H. R. , Ketelaar J. A. A. 
Published: September 2010

AbstractA calculation is given for the opposing resonance in an “energy”‐rich phosphate ester from the hypsochromic shift of the first ultraviolet absorption maximum for phenyl and nitrophenyl phosphates. The effects contributing to the standard free energy of hydrolysis in energy‐rich phosphate bonds are discussed.
Tripyridyl carbinols: A group of tertiary alcohols with amphoteric properties: 104th Communication on pyridine derivatives
Authors: Wibaut J. P. , Otto P. Ph. H. L. 
Published: September 2010

AbstractThe synthesis of five new tripyridyl carbinols is described, so that seven out of the ten possible isomers of this group are now known. The tripyridyl carbinols are not only weak bases, they show also the properties of very weak acids; the acid dissociation constants are of the order of magnitude of 10−12 to 10−14 and were determined from the relationship between the solubility in dilute alkali and the hydroxyl‐ion concentration. The connection between structure and acid properties is discussed.
Polarography of potassium manganate
Authors: Den Boef G. , Poeder B. C. 
Published: September 2010

AbstractThe polarography of compounds in the higher valency states of manganese, already carried out for permanganate by other authors, is extended to alkaline solutions by investigating the polarographic reduction of the manganate ion at the dropping mercury electrode, as well as at the rotating platinum electrode. Quantitative determinations of manganate appear to be possible in the concentration range from 2 × 10−3 M to 2 × 10−5 M.
Researches on the alkoxy‐amino‐nitrobenzenes: VIII. Preparation and anaesthetic properties of a number of dialkylaminoalkyl and bis (dialkylamino) alkyl esters of (alkoxynitrophenyl) carbamic acids
Authors: Verkade P. E. , Strube R. E. , Witjens P. H. 
Published: September 2010

AbstractThe preparation of a number of dialkylaminoalkyl and bis (dialkylamino) ‐alkyl esters of (alkoxy‐nitrophenyl) carbamic acids is described. The substances obtained were tested for (local) anaesthetic activity with the aid of the rabbit cornea test, the frog muscle sciatic nerve test and the goldfish test.
Researches on plant growth regulators, XXV. Structure/activity, X. On the influence of the polar group on growth substance transport: Comparative investigations with14C‐labeled indolylacetic acid and indolylmethanesulphonic acid
Authors: van de Westeringh C. , Veldstra H. 
Published: September 2010

AbstractBy comparative investigations with 3‐indolylacetic acid and its sulphonic acid analogue, both labeled with14C in the CH2‐group of the side chain, it was shown that the uptake of the partly dissociated carboxylic acid is much higher than that of the completely dissociated sulphonic acid. This explains the high external concentrations required for the latter to show physiological activity.As the synergist di‐n‐amylacetic acid does not influence the uptake of the growth substances, its action must be concerned with a redistribution of the active compounds inside the cell.