bluuebunny/crossref_metadata_2025_split huggingface dataset:
The change in the composition of the cocaines in java coca leaves during their growth. The acids of the esters of l‐nor‐ecgonine from coca leaves
Authors: de Jong A. W. K. 
Published: September 2010

AbstractThe contradiction noted previously, that the quantity of the cocaines in the leaves on a branch remains almost constant for 8 successive leaves with the exception of that of the youngest leaf, while the composition of the cocaines in the leaves alters during their growth, ‐ young leaves contain more cinnamylcocaines than cocaine and old leaves more cocaine than cinnamylcocaines, ‐ is explained as being caused by the continuous formation of fresh cocaines in the leaves, and the continuous decomposition of an almost equal quantity of cocaines containing less cocaine and more cinnamylcocaines than the percentages in the fresh formed cocaines. Reasons for the quicker decomposition of the cinnamylcocaines in the leaves are indicated.In agreement with this explanation it is noted, that the acids of the esters of l‐nor‐ecgonine consist for the main part of formic acid, benzoic acid being not present. The way in which l‐nor‐formylecgonine can be formed in the leaves from the cinnamylcocaines is indicated.
A new method for the synthesis of furan derivatives: I. Introduction
Authors: Morel Th. , Verkade P. E. 
Published: September 2010

AbstractA new method for the synthesis of furan derivatives is outlined. By the action of a mixture of concentrated sulphuric acid and acetic anhydride in the molecular ratio of 1:2 on αβ‐ or β γ‐unsaturated ketones, having a branching of the carbon skeleton in the β‐position, δ‐sultones with two conjugated double bonds in the hetero‐ring are obtained. On pyrolysis these δ‐sultones yield sulphur dioxide and a furan derivative.
The‐rate of hydrolysis and composition of tetraethyl pyrophosphate (T.E.P.P.)
Authors: Ketelaar J. A. A. , Bloksma A. H. 
Published: September 2010

AbstractTetraethyl pyrophosphate hydrolyses in a first order reaction with a value of the rate constant of 0.093 h−1 at 25° C and an activation energy of 10.7 kcal/mol. Technical preparations with this substance as active ingredient contain also triethyl orthophosphate and probably polymeric ethyl metaphosphate. By extraction and molecular distillation the components can be separated and pure T.E.P.P. can be obtained. The polymeric ethyl metaphosphate apparently hydrolyses very rapidly probably to symmetric diethyl pyrophosphoric acid thus giving rise to the first rapid formation of acid on dissolving technical preparations in water. A third, very slow hydrolysis observed is probably due to the further hydrolysis of this pyrophosphoric acid ester to monoethyl orthophosphoric acid.
On the use of Evjen's method in calculating madelung potentials
Authors: de Boer F. 
Published: September 2010

AbstractThe complications, arising when Evjen's method is applied to lattices, where the finite part used in the calculation has surfaces which are not electrically neutral, are investigated for a simple lattice: the CsCl lattice bounded by cube faces. A correction is calculated and is applied to the spinel lattice.
The photometric determination of cobalt with nitroso‐R‐salt
Authors: Claassen A. , Westerveld W. 
Published: September 2010

AbstractAs the result of a discussion on the choice of the most suitable wavelength to be used in the photometric determination of cobalt with nitroso‐R‐salt, a wave‐length of 550 mμ is recommended, using absorption cells of 2 to 5 cm length.The interference by copper and nickel is extensively dealt with. Some data are given on the interference by other elements.
Relations between refraction, density and structure of series of homologous hydrocarbons. II. Refraction and density at 20° C of n. alkyl‐cyclopentanes, ‐cyclohexanes and ‐benzenes
Authors: Smittenberg J. , Mulder D. 
Published: September 2010

AbstractIn continuation of the first publication of this series mathematical relations were developed between refraction, density and number of carbon atoms per molecule for n‐alkyl‐cyclopentanes, ‐cyclohexanes and benzenes. The results are compared with those of the n‐alkanes and n‐alpha‐alkenes, presented in the first publication.
The crystal structure of glutaric and pimelic acid. Alternation of properties in the series of dicarboxylic acids
Authors: Macgillavry Caroline H. , Hoogschagen G. , Sixma F. L. J. 
Published: September 2010

AbstractGlutaric acid and pimelic acid have analogous crystal structures. The CH2 chains are stretched along the c‐axis, the plane of the zigzag is nearly parallel to (100). Packing of the COOH groups is practically identical to that in adipic acid. This packing enforces a torsion in the molecules of the odd acids as a result of their axial symmetry. This torsion may well be the cause of the higher energy content of the odd dicarboxylic acids; an estimate of the torsion energy is made and is shown to be of the right order of magnitude.
Les Propriétés du Groupe Sulfonyle: III. Oxydation du tétrathioorthocarbonate tétraméthylique
Authors: Backer H. J. 
Published: September 2010

AbstractLe tétrakis‐méthylthio‐méthane, en présence d'acide perbenzoïque en excès, consomme 7 à 8 atomes d'oxygéne. En lavant le produit d'oxydation à l'eau, on élimine de l'acide méthanesulfonique.Le résidu est un mélange, dont on peut séparer, par des procédés variés, le tris‐méthylsulfonyl‐méthane CH(SO2Me)5 (acide fort). Le principal composant du mélange peut engendrer une sulfoxyde‐disulfone (MeSO)CH(SO2Me)2, dont il est peut‐étre un isomère; il se décompose à 110° en donnant l'acide méthanesulfonique, le dioxyde de diméthyldisulfure Me2S2O2 et d'autres produits encore. II n'est pas impossible qu'une tétrasulfone se soit formée parmi les produits primaires de l'oxydation, et, si c'est le cas, elle s'est décomposée rapidement.En introduisant deux groupes thiométhyle dans le bis‐méthylsulfonyl‐méthane, on synthétise un dérivé du tétrathioéther avec deux groupes sulfonyle (MeS)2C(SO2Me)2, dérivé qui, soumis à l'oxydation, se comporte, dans les grand lignes, comme le tétrathioéther. On n'obtient pas de tétrasulfone.
Les Potentiels Electrocinetiques du Sulfate de Barium
Authors: Ruyssen R. , Loos R. 
Published: September 2010

AbstractLe potentiel d'écoulement de cristaux de BaSO4 en milieu hydroalcoolique a été mesuré. Dans certains cas on observe une positivation des cristaux. Ce phénomène parait étre dû à une désorption des ions sulfuriques ou à l'adsorption des ions barium.
1,3,5‐Tri‐p‐methoxybenzylcyclohexane
Authors: van der Zanden J. M. , de Vries G. 
Published: September 2010

AbstractBoth stereo‐isomers of 1,3,5‐tri‐p‐methoxybenzylcyclohexane (CH3O. C6H4. CH2)3C6H9have been synthesized in connection with our investigation on polymerisation products from methylchavicol.
On some derivatives of diphenylamine
Authors: Blanksma J. J. 
Published: September 2010

AbstractThe coupling of 1‐chloro‐2,4‐dinitrobenzene with 3,5‐dichloroaniline gives 3,5‐dichloro‐2′,4′‐dinitrodiphenylamine. The nitration of this formerly unknown compound with anhydrous nitric acid gives 3,5‐dichloro‐2,4‐2′,4′‐tetranitrodiphenylamine, in which the chlorine atoms are mobile and can be replaced by amino groups.The partial reduction of 2,4‐dinitrodiphenylamine and its derivatives can be accomplished better with Na2S2 than with Na2S. magnified image
Steric effects on mesomerism. IV. Steric effects on mesomerism in derivatives of ortho‐nitro‐acetanilide
Authors: Wepster B. M. , Verkade P. E. 
Published: September 2010

AbstractThis paper contains data on the (pseudo) catalytic deacylation of a number of derivatives ofortho‐nitro‐acetanilide in which steric effects on mesomerism are to be expected. The rate of deacylation found for each compound is discussed in some detail on the basis of current electronic theory.It is shown that the occurrence of steric inhibition of mesomerism can sometimes be used to advantage in the separation of mixtures of isomeric nitroaryl‐acylamines.
Halogen derivatives of isoprene
Authors: Ultée A. J. 
Published: September 2010

AbstractMany halogen derivatives of isoprene were prepared and their structure studied, the starting materials being two addition products of hydrochloric acid and isoprene. This addition leads to 3‐chloro‐3‐methylbutene‐l, i.e. 1,2‐addition (II), which had not been isolated by previous workers. This tertiary chloride undergoes an allylic rearrangement to the primary chloride (I) under the catalytic influence of hydrochloric acid.Chlorine on the other hand yields mainly the 1,4‐addition product of isoprene1) (VI), but the 3,4‐addition product (V) is also formed as a by‐product.Sulphuryl chloride in the presence of peroxides reacts in the expected way, leading essentially to the additon of two chlorine atoms to the double bond. In the presence of an anti‐oxidant, however, substitution becomes predominant. This result is contrary to the previous experience of Kharash and Brown2) with olefines.Vinyl halides with a chlorine atom in α‐position to the vinyl chloride do not add iodine chloride.Only vinyl halides are non‐reactive with piperidine (in nitrobenzene solution) at 100°. This reaction can therefore be used for the identification of vinyl halide groups.
A complete extraction of the bases and the acid esters of l‐nor‐ecgonine from coca leaves. II
Authors: de Jong A. W. K. 
Published: September 2010

AbstractThe results of experiments have shown that 20 g of coca leaves manipulated as previously indicated should be extracted first with a mixture of 400 cm3 of benzene with 20 cm3 of methyl alcohol and thereafter with about 600 cm3 of the 58° boiling mixture, to obtain complete extraction of the bases.It is argued, that after the addition of the ammonia solution to the leaves deprived of their moisture by powdered quick lime present in the mixture of benzene with about 5% by volume of methyl alcohol, an equilibrium is formed in the unbroken cells of the leaves between the base salts, the bases and ammonia in dilute methyl alcohol. The bases outside the cells will be set free by calcium hydroxide. The acid esters of l‐nor‐ecgonine in the unbroken cells will be in the free state after the action of ammonia and will be converted to calcium salts outside the cells. Therefore it will be an adventage to use coarse pulverised leaves for extraction.
Derivatives of bis(4‐aminophenyl)‐sulfone II. Condensation of bis(4‐aminophenyl)‐sulfone with some aromatic aldehydes
Authors: Sah Peter P. T. , Oneto John F. , Rohrmann Ewald , Kleiderer E. C. 
Published: September 2010

AbstractFor chemotherapeutic studies, five anils were prepared by the direct condensation of bis(4‐aminophenyl)‐sulfone (I) in absolute ethanol with aromatic aldehydes, i.e. bis (4‐o‐chlorobenzalaminophenyl)‐sulfone (II) from I and o‐chlorobenzaldehyde, bis (4‐p‐chlorobenzalaminophenyl)‐sulfone (III) from I and p‐chlorobenzaldehyde, bis (4‐o,p‐dichlorobenzalaminophenyl)‐sulfone (IV) from I and o,p‐dichlorobenzaldehyde, bis(4‐m,p‐dichlorobenzalaminophenyl)‐sulfone (V) from I and m,p‐dichlorobenzaldehyde, bis (4‐2′‐hydroxy‐1′‐naphthalaminophenyl)‐sulfone (VI), from I and 2‐hydroxy‐1‐naphthaldehyde.Of this group of anils II is the most active biologically. Its antitubercular activity is comparable to salicylacetone. It is also slightly more effective than sulfanilamide in streptococci hemolyticus infected mice at 5 mg X 2 dosage.
Complexresonance. Preliminary communication
Authors: Brackman W. 
Published: September 2010

AbstractThe colour effects, which occur in the liquid phase in mixtures of quinones or nitro compounds on the one hand and unsaturated or aromatic compounds on the other, are attributed to complexresonance. By this is understood a covalent binding between two molecules, the character of which lies in between that of a single bond and no bond at all.A summary is given of the two types of substances which can exhibit complexresonance with each other and of the phenomena which are associated with complexresonance.Complexresonance is considered as the cause of a number of cases of quenching of fluorescence. In addition it is considered of importance for the formation of the activated complex of certain reactions and for the explanation of some types of enzymatic reactions.
La Réaction Entre L'orthoformiate D'éthyle et les Amines Aromatiques Primaires
Authors: Backer H. J. , Wanmaker W. L. 
Published: September 2010

AbstractLa réaction des amines aromatiques primaires sur l'orthoformiate d'éthyle ne donne pas les orthoformamides HC(NHR)3, mais les formamidines RN : CH.NHR. La réaction entre l'aniline et l'acétate de diéthoxyméthyle conduit également à une amidine.Tous les composés décrits dans la littérature comme orthoformamides d'amines primaires sont des amidines.
2‐Thiobenzaminonaphthalene: Discrepancies in the literature VII
Authors: van Alphen J. , Drost G. 
Published: September 2010

AbstractThe melting point of 2‐thiobenzaminonaphthalene is 164°. When 1 mol. 2‐aminonaphthalene, 1 mol. benzaldehyde, and 1 at. sulphur are heated at 170–180°, not 2‐thiobenzaminonaphthalene, but 2‐phenyl‐naphtho‐2′,1′: 4,5‐thiazole is obtained.
Absorption spectra of quinones. II. Anthraquinones and heterocyclic analogues
Authors: Spruit C. J. P. 
Published: September 2010

AbstractIt has been shown with a number of examples that, as an approximation, the absorption spectra of derivatives of anthraquinone may be obtained by adding the absorption spectra of the naphthoquinones corresponding to the two halves of the anthraquinone molecule. The deviations from strict additivity are discussed. The spectra of derivatives of lin. naphthindazolquinone are remarkably similar to those of the analogous anthraquinones. This is a new example of the aromatic properties of the pyrazole nucleus.
2‐Methylbuten‐3‐yl 2‐methyl ether and 2‐methylbuten‐2‐yl 4‐methyl ether
Authors: Ultée A. J. 
Published: September 2010

AbstractThe ether obtained by Supniewsky1) by the action of calcium cyanamide and potash on isoprene hydrobromide in methyl alcoholic solution, does not possess the structure (CH3)2C:CH. CH2OCH3, given by this investigator, but is (CH3)2. C(OCH3). CH:CH2. Both ethers have been prepared.
Studies in filtration: Part I
Authors: Heertjes P. M. , Haas H. V. D. 
Published: September 2010

AbstractIn this paper a study is given about the initial stages of filtration at constant pressure from which conclusions could be drawn about the interrelation between cloth and cake.It was found that ‐ with one system ‐ two types of filtration may occur, blocking filtration and cake filtration, depending on the concentration of the solid substance in the prefilt: By increasing this concentration blocking gradually decreases and finally blocking filtration changes to cake filtration.With cake filtration at constant pressure the specific resistance of the cake depends on the concentration in the prefilt; decreasing with increasing concentration.An equation for complete blocking filtration has been derived.
Direct observation of variations in electrode potentials by means of the Cathode‐Ray oscillograph
Authors: Lebbink F. J. , Weydema J. , Burgers W. G. 
Published: September 2010

AbstractThe rapid variations in potential of the electrodes in an electrolytic cell when closing or interrupting the current were made visible on the screen of a cathode‐ray oscillograph as a repeating image. This was achieved by using a periodically interrupted current, obtained by means of an electronic interruptor.Indication of time was realized by means of a periodic suppression of the cathode ray.A particular feature of the measuring equipment is the possibility of complete synchronisation of its different parts.
Synthesis of polychloro compounds with aluminium chloride VIII. Decachlorohexadiene‐1,5, its isomerisation, cyclisation and cleavage
Authors: Prins H. J. 
Published: September 2010

AbstractThe present paper describes the action of dechlorination agents upon hexachloropropene the preparation of decachlorohexadiene‐1,5, of a liquid isomer, probably decachlorohexadiene‐2,4, the cleavage and the cyclisation of both compounds. The compound obtained by cyclisation, a decachloromethylcyclopentene, can be cleaved into carbon tetrachloride and hexachlorocyclopentadiene.
Derivatives of 2,4‐dichlorophenoxyacetic hydrazide
Authors: Chao Janice Chung‐Chin , Sah Peter P. T. , Oneto John F. 
Published: September 2010

AbstractEthyl ester of 2,4‐D (2,4‐dichlorophenxyacetic acid) (I), colorless liquid, b.p. 149‐155° at 5 mm, was prepared with good yield by allowing the acid to react with thionyl chloride and then decomposing the acid chloride with absolute ethyl alcohol.80 g of (I) reacted with 20.4 g of 85% hydrazine hydrate in 10 cm3 absolute ethyl alcohol gave 75.1 g of hydarzide (II), colorless needles from 95% ethyl alcohol, m.p. 155‐157°.II in 95% ethanol condensed with aldehydes and ketones formed crystalline hydrazones. Twenty‐one hydrazone derivatives were prepared for plant growth studies.
A new synthesis of benzo (b) thiophanthrene
Authors: Werner E. G. G. 
Published: September 2010

AbstractWhen heated, the compound obtained by benzoylation of 3‐methyl‐benzo‐thiophene forms benzo (b) thiophanthrene (Elbs reaction). This proves that this benzoylation has resulted in the formation of the 2‐benzoyl‐3‐methyl benzothiophene.The benzo (b) thiophanthrene was also synthesized by starting from dibenzothiophene.Ultraviolet absorption spectra were measured.
L'Action de L'Acide Chlorhydrique Gazeux sur la Cyanhydrine Acetonique
Authors: Ultée A. J. 
Published: September 2010

AbstractDans une communication provisoireCe Recueil28, 349 (1909)., il a été démontré que du produit obtenu par l'action de l'acide chlorhydrique gazeux sec sur la cyanhydrine acétonique et addition subséquente d'un égal volume d'eau, deux composés peuvent être isolés: le chlorhydrate d'une base C8H14O2N2, contenant une molécule d'eau de cristallisation, et un produit C12H19O5N.On donne maintenant la preuve que la base est un imino‐éther, le (1‐méthyl‐1‐cyano‐éthyl) (2‐méthyl‐1‐imino‐2‐hydroxypropyl) éther (chlorhydrate I), tandis que, pour le deuxiéme produit, la formule III (3,3,6,6,8,8‐hexaméthyl‐(1‐aza‐4,7‐dioxa‐cyclo‐nonatrione‐2,5,9)) semble très vraisemblable.
A new method of preparing glycollide
Authors: Sporzyński A. , Kocay W. , Briscoe H. V. A. 
Published: September 2010

AbstractThe thermal decomposition of sodium chloracetate under reduced pressure in the presence of copper gave glycollide with a yield exceeding 70%. Other salts of chloracetic acid can be used with equally good results. Metals other than copper gave inferior results. Glycollide serves as a convenient starting material for the preparation of glycollic acid and its esters.
Researches on the alkoxy‐amino‐nitrobenzenes: VI. A survey of their anaesthetic properties
Authors: Verkade P. E. , van Dijk C. P. , Witjens P. H. 
Published: September 2010

AbstractThe anaesthetic properties of a number of alkoxy‐amino‐nitrobenzenes belonging to all ten possible types have been studied with the aid of three different methods: the rabbit cornea test, the frog muscle sciatic nerve test and the goldfish test. The data obtained thus relate to surface anaesthesia, block anaesthesia and general (central) anaesthesia. These data are discussed from a purely chemical point of view. The pharmacological part of the work and a discussion of the data from a pharmacological point of view will be published elsewhere.
A method for the accurate calculation of some thermodynamic properties of non‐polar or moderately polar substances, based on Van Laar's theory
Authors: Heukelom W. 
Published: September 2010

AbstractVan Laar's method to calculate the critical conditions is based on the molecular constants a and b in van der Waals' equation of state. In certain cases inaccuracies in the calculated values of a may lead to results which deviate considerably from the experiment. In the present article it is demonstrated that the accuracy may be increased to a considerable extent by replacing the constant a in the calculations by less fundamental magnitudes, such as the boiling point and the vapour tension factor. It is found that in the latter case the probable error is of the same order of magnitude as the experimental error. An extensive survey is given of the results for several substances of different structural types. A brief survey is given of some further data which can be calculated from the results obtained.
On the sweet taste of 1‐n‐propyl‐2‐amino‐4‐nitrobenzene
Authors: Blanksma J. J. 
Published: September 2010

AbstractThe 1‐alkyl‐2‐amino‐4‐nitrobenzenes are sweet in taste. 1‐Methyl‐2‐amino‐4‐nitrobenzene is 330 times as sweet as cane sugar, 1‐n‐propyl‐2‐amino‐4‐nitrobenzene, which has now been investigated is 2000 times as sweet as cane sugar. 1‐Methyl and 1‐n‐propyl‐2‐nitro‐4‐aminobenzene are tasteless. The acetyl derivatives of all of these compounds are tasteless.
Mechanism of reinforcement III: Viscosity of carbon black suspensions in GR‐S solutions
Authors: Amborski Leonard E. , Goldfinger George 
Published: September 2010

AbstractThe viscosity of carbon black suspended in GR‐S solutions has been investigated in a Stormer‐type viscosimeter at various rates of shear. Relative viscosities thus determined have been extrapolated to zero rate of shear and by applying Einstein's viscosity equation the volume of the suspended particles has been calculated. It has been found that under the conditions examined the carbon black particles are surrounded by a rubber layer 150 to 200 Ängstroms thick.
Substitution Centrale Dans le Tris‐Méthylsulfonyl‐Méthane (Les Propriétés du Groupe Sulfonyle VI)
Authors: Backer H. J. 
Published: September 2010

AbstractL'hydrogène lié à l'atome central de carbone du tris‐méthylsulfonyl‐méthane peut être substitué par des métaux, le chlore. le brome, le méthyle, les thioaryles et même par le groupe nitro. Plusieurs produits de substitution qui sont difficilement ou pas du tout accessibles par voie directe se laissent obtenir en suivant un détour, par oxydation de composés qui n'ont que deux groupes CH3SO2, à cǒté d'un groupe CH3S. Ces composés substitués et partiellement oxydés XC(SCH3) (SO2CH3)2 peuvent étre obtenus selon deux méthodes: introduction finale soit de X, soit de SCH3.Enfin les substitutions réalisées sont examinées au point de vue de la théorie électronique. Elles se rangent toutes parmi les substitutions électrophiles.
Hydrolyse des Produits Obtenus par Substitution Centrale du Tris‐Méthylsulfonyl‐Méthane (les Propriétés du Groupe Sulfonyle VII)
Authors: Backer H. J. 
Published: September 2010

AbstractLes dérivés quaternaires du tris‐méthylsulfonyl‐méthane XC(SO2CH3)3 sont hydrolysés en solution alcaline. Souvent l'hydrolyse s'accomplit à froid déjà. Au cas où le groupe substituant X est CH3, C6H5, C6H5S, CH3C6H4S ou NO2, un groupe ‐SO2CH3 est expulsé sous forme d'acide méthane‐sulfonique. L'hydrolyse de la nitrotrisulfone O2NC (SO2CH3)3 donne naissance à la nitrodisulfone O2NCH (SO2CH3)2, que l'on identifie aisément sous la forme de sels ou du dérivé bromé O2NCBr(SO2CH3)2.
Oxidative phenomena in dilute solutions of substances with a system of conjugated double bonds. II. Alkali‐isomerized linoleic acid
Authors: Groot E. H. , Monnikendam Ph. 
Published: September 2010

AbstractAbnormal spectra with absorption maxima at 310‐, 273‐ and below 225 mμ are sometimes obtained in very dilute solutions of alkali‐isomerized linoleic acid in various solvents. In all probability these anomalies are connected with the occurrence of autoxidative processes in the solutions.