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Showing papers in "Recueil des Travaux Chimiques des Pays-Bas in 1948"


Journal ArticleDOI
TL;DR: In this article, when a gaseous component is absorbed by a liquid under simultaneous reaction with a component of the liquid, the overall rate of reaction proves to be a dimensionless function of four limiting rates.
Abstract: When a gaseous component is absorbed by a liquid under simultaneous reaction with a component of the liquid, the overall rate of reaction proves to be a dimensionless function of four limiting rates: a.the maximum rate of diffusion of the gaseous component through the liquid film b.the maximum rate of diffusion of the liquid-component through the liquid film c.the limiting rate of reaction within the liquid film (during diffusion) d.the maximum rate of reaction within the main body of the liquid. A graphical representation of the theoretical relationship enables one to predict the overall rates of interphase mass exchange under arbitrary conditions, as soon as reaction velocity coefficients and mass transfer coefficients are available.

227 citations


Journal ArticleDOI
TL;DR: The Synthese von 1-Desaza-adenin, dem von einem Imidazopyridin abgeleiteten Analogen des Adenins, is described in this article.
Abstract: Ersetzt man in der Formel eines Purin-Derivats eines oder mehrere der Stickstoffatome des Ringsystems durch Methingruppen, so gelangt man zu Strukturtypen, fur die sich durch Verwendung des Praefix „Des-aza-” einfache Bezeichnungen ableiten lassen. Wir haben uns die Aufgabe gestellt, derartige Verbindungen zu synthetisieren und zu prufen ob und inwieferne sie als Hemmstoffe physiologischer Prozesse wirksam sind. Die vorliegende Mitteilung beschaftigt sich mit der Synthese von 1-Desaza-adenin, dem von einem Imidazopyridin abgeleiteten Analogen des Adenins. Seine Darstellung hatte die Synthese des bisher ebenfalls unbekannten 2,3,4-Triamino-pyridins zur Voraussetzung.

35 citations


Journal ArticleDOI
TL;DR: In this article, the β-ionylidene acetaldehyde VI was obtained in fair yield starting from β -ionone III (==================€€€£€£££ £€£ £ ££ £££€ ££€€ £ £ £€ £€ €££/$££$££ €£ £/$£ £$£ £ €£€/$ ££/$€£ €€£/$ £ £/$ £€€$ ££ $€£
Abstract: Ethoxyacetylene carbinols can be partially hydrogenated to the corresponding ethylenecarbinols, which on hydrolysis yield α,β-unsaturated aldehydes. β-ionylidene acetaldehyde VI could be obtained in fair yield starting from β-ionone III ( ). This substance was identical with the β-ionylidene acetaldehyde, described by Kuhn and Morris. Citral and β-methylcinnamic aldehyde were prepared also.

28 citations


Journal ArticleDOI
TL;DR: Three acylating mechanisms are involved in the reaction between amides and anhydrides in the aliphatic series all mechanisms are governed by the inductive effects operating in the reactants.
Abstract: Three acylating mechanisms are involved in the reaction between amides and anhydrides In the aliphatic series all mechanisms are governed by the inductive effects operating in the reactants Amides act as acids towards anhydrides Diacylimines and the corresponding anhydrides acylate alcohols by the same mechanism A new compound, propionylchloroacetamide, has been prepared Properties of some diacylimines have been established Uses for diacylimines are suggested

20 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that the packing of the COOH groups is practically identical to that in adipic acid, which may explain the higher energy content of odd dicarboxylic acids; an estimate of the torsion energy is made and is shown to be of the right order of magnitude.
Abstract: Glutaric 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.

18 citations


Journal ArticleDOI
TL;DR: In der vorliegenden Arbeit wird gezeigt, dass die in der Literatur als 4(7)-Amino-benzimidazol beschriebene Verbindung in Wirklichkeit die Aminogruppe an Stelle 5 (bzw. 6) tragt as mentioned in this paper.
Abstract: In der vorliegenden Arbeit wird gezeigt, dass die in der Literatur als 4(7)-Amino-benzimidazol beschriebene Verbindung in Wirklichkeit die Aminogruppe an Stelle 5 (bzw. 6) tragt. Das bisher unbekannte 4(7)-Aminobenzimidazol - dem wegen seiner strukturellen Beziehung zu Adenin ein gewisses Interesse zukommt - wurde dargestellt und mit der isomeren Verbindung verglichen.

18 citations


Journal ArticleDOI
TL;DR: The solubility of 2-aminofluorene has been examined in aqueous solutions of various purines and the results are of the same order as those obtained by Weil-Malherbe for the solubilities of benzpyrene in solutions of same purines as mentioned in this paper.
Abstract: The solubilities of the carcinogenic amines, 2-naphthylamine, 2-aminofluorene, 2-anthramine, 4-aminostilbene, 4-aminoazobenzene and benzidine in water and in aqueous solutions of caffeine have been examined and it has been found that caffeine exerts a solubilising action on all these amines. Caffeine has quite a marked solubilising action on the simpler amine, 1-methoxy-2-amino-4-nitrobenzene and it has been shown that sulphapyridine and sulphathiazole are more soluble in caffeine solutions than in water. The solubility of 2-aminofluorene has been examined in aqueous solutions of various purines and the results are of the same order as those obtained by Weil-Malherbe for the solubility of benzpyrene in solutions of the same purines. The most efficient purines are those with the greatest degree of N-methylation. The influence of a mixture of caffeine and 1,3,7-trimethyluric acid on the solubility of 2-aminofluorene in water has been studied and it is shown that the solubilising power of the mixture is less than the sum of the separate effects of each purine on the solubility of the amine. This is taken to mean that the purines antagonise each other probably owing to forces acting between themselves of the same nature as those responsible for the aminofluorene-purine solubility effects. This effect, which requires further study would probably be of importance in biological systems. Some evidence is given that 2-phenyl-quinoline-4-carboxylic acid (cinchophen) is solubilised by aqueous solutions of caffeine.

17 citations


Journal ArticleDOI
TL;DR: In this paper, a 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.
Abstract: A 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.

15 citations


Journal ArticleDOI
TL;DR: In this paper, various new tests are introduced such as: Resolin B-Solidogen BSE test, KI3 test, ammonium cobalt thiocyanate test, Chlorantinlichtbraun BRLL test, diazo test, starch iodine test, alkaline distillation, the heating test and the acid heating test.
Abstract: An attempt has been made, in the domain of washing, wetting, retarding agents and emulsifiers to produce a system of qualitative analysis which embraces more groups of compounds within this field than has been the case up to the present To this end various new tests are introduced such as: the Resolin B-Solidogen BSE test, the KI3 test, the ammonium cobalt thiocyanate test, the Chlorantinlichtbraun BRLL test, the diazo test, the starch iodine test, alkaline distillation, the heating test and the acid heating test

15 citations


Journal ArticleDOI
TL;DR: In this paper, a tetrakis-methylthio-methane, en presence d'acide perbenzoique en exces, consomme 7 a 8 atomes d'oxygene.
Abstract: Le tetrakis-methylthio-methane, en presence d'acide perbenzoique en exces, consomme 7 a 8 atomes d'oxygene. En lavant le produit d'oxydation a l'eau, on elimine de l'acide methanesulfonique. Le residu est un melange, dont on peut separer, par des procedes varies, le tris-methylsulfonyl-methane CH(SO2Me)5 (acide fort). Le principal composant du melange peut engendrer une sulfoxyde-disulfone (MeSO)CH(SO2Me)2, dont il est peut-etre un isomere; il se decompose a 110° en donnant l'acide methanesulfonique, le dioxyde de dimethyldisulfure Me2S2O2 et d'autres produits encore. II n'est pas impossible qu'une tetrasulfone se soit formee parmi les produits primaires de l'oxydation, et, si c'est le cas, elle s'est decomposee rapidement. En introduisant deux groupes thiomethyle dans le bis-methylsulfonyl-methane, on synthetise un derive du tetrathioether avec deux groupes sulfonyle (MeS)2C(SO2Me)2, derive qui, soumis a l'oxydation, se comporte, dans les grand lignes, comme le tetrathioether. On n'obtient pas de tetrasulfone.

14 citations


Journal ArticleDOI
TL;DR: In this paper, it was shown that the bromine atoms occupied the 2 and 6 positions in the 2-6-dibromo-derivative melting at 142°.
Abstract: Two dibromo-diethoxypyridines of undetermined structure are described in the literature, viz. a compound melting at 142° by Sell and an isomer with m.p. 165°, by Konigs, Gerdes and Sirot. We have shown that the bromine atoms occupy the 2 and 6 positions in the bromo-derivative melting at 142°. The compound melting at 165°, prepared according to the directions of Konigs and his co-workers, appears to be 2-bromo-3,5-diethoxy-6-nitro-pyridine instead of a dibromo-diethoxypyridine. 2,6-Dibromo-3,5-diethoxypyridine was isolated by Sell as the sole reaction product from the bromination of 3,5-diethoxypyridine in an acid medium. By carrying out the bromination in pyridine as solvent, we have obtained 2-bromo-3,5-diethoxypyridine along with the dibromo-compound. The further bromination of this mono-bromo-compound is a reversible process; the dibromo-derivative is converted into mono-bromo-diethoxypyridine by heating with a solution of hydrobromic acid in glacial acetic acid. Finally we have examined the action of cuprous cyanide, sodium ethylate and nitric acid on the 2-bromo- and the 2,6-dibromo-derivative of 3,5-diethoxypyridine. In proving the structure of derivatives of 3,5-diethoxypyridine, the possibility of the occurrence of various abnormal substitution reactions with these substances must be taken into account.

Journal ArticleDOI
TL;DR: In this article, the rate of mass transfer in granular beds has been studied by determining the dissolution rate of benzoic acid in water and aqueous glycerol solutions and of sulphur in benzene.
Abstract: Rate of mass transfer in granular beds has been studied by determining the rate of dissolution of benzoic acid in water and aqueous glycerol solutions and of sulphur in benzene. For liquid-continuous flow and film-like flow, mass transfer coefficients could be correlated by dimensionless equations

Journal ArticleDOI
TL;DR: For example, in this article, the dioxyde lui-meme doit etre la cause de cette propriete remarquable, a propriete reductrice d'une solution ammoniacale de thiouree ne peut pas etre attribuee a la formation passagere du sel d'ammonium de l'acide sulfoxylique, car les ethers ethyliques de cet acide, en solution alcaline, ne precipitent pas les sels de cadmium a
Abstract: La propriete fortement reductrice d'une solution ammoniacale du dioxyde de thiouree ne peut pas etre attribuee a la formation passagere du sel d'ammonium de l'acide sulfoxylique, car les ethers ethyliques de cet acide, en solution alcaline, ne precipitent pas les sels de cadmium a l'etat de cadmium metallique. Le dioxyde lui-meme doit etre la cause de cette propriete remarquable. Cependant, la decomposition en solution ammoniacale: est prouvee par la presence, apres quelque temps, des ions S2O3, SO4, SO3 et S. Le Ni et le Cd precipites contiennent toujours des quantites assez considerables de S et d'oxygene. Le fait que le cadmium et tous les elements plus electronegatifs provoquent un degagement lent d'hydrogene peut etre deduit de la place de l'hydrogene dans la serie des forces electromotrices des elements. En solution ammoniacale, le dioxyde s'empare d'un atome d'oxygene: en presence des sels de Ni, Fe, Co, etc., deux atomes d'oxygene sont fixes; le soufre est alors transforme en sulfate. Cette reaction, partiellement catalytique, a ete etudiee de plus pres. La methylthiouree donne avec H2O2 l'acide methylformamidine-sulfinique, qui montre les memes reactions que l'acide formamidine-sulfinique lui-meme; en solution aqueuse et legerement acide, il est un peu plus stable. Enfin, nous avons etudie l'oxydation de la benzylisothiouree par H2O2, dans l'espoir d'obtenir l'ether benzylique de l'acide formamidine-sulfinique, mais en vain. En oxydant la benzylisothiouree par l'acide peracetique, nous avons obtenu une substance C23H17S3N3O5; dont nous avons etabli la structure avec quelque probabilite.

Journal ArticleDOI
TL;DR: 3-Acetylamino-5-ethoxypyridine as mentioned in this paper was prepared by converting 3,5-dibromopyridine with sodium ethylate into 3-bromo-5,ethoxymidine, allowing this substance to interact with ammonia and acetylating the aminoethoxymbolidine thus formed with acetic anhydride.
Abstract: 3-Acetylamino-5-ethoxypyridine was prepared by converting 3,5-dibromopyridine with sodium ethylate into 3-bromo-5-ethoxypyridine, allowing this substance to interact with ammonia and acetylating the aminoethoxypyridine thus formed with acetic anhydride.

Journal ArticleDOI
TL;DR: In this article, the authors derived the frequencies of the total symmetrical vibrations of the molecules of P4O6, P 4O6S4 and P 4 O6O4, all of which have the symmetry Td, making use of the bond distances and bond angles determined by Hampson and Stosick.
Abstract: Numerical equations are derived for the frequencies of the total symmetrical vibrations of the molecules of P4O6, P4O6S4 and P4O6O4, all of which have the symmetry Td, thereby making use of the bond distances and bond angles determined by Hampson and Stosick and by Stosick in their electron diffraction measurements. Force constants have been calculated for P4O4, using the results of Raman spectroscopic investigations, which we made previously, and the simplified assumption that the two deformational force constants d1 and d2 have the same value. f1 is then found to be 4.75 × 105 and d1 = d2 to be 0.35 × 105 dyne/cm. This value for f substituted in Badger's formula, leads to a value for the P—O bond distance, which is in good agreement with that determined directly by the electron diffraction method. For P4O6S4 and P4O6O4 that value for f2 (the force constant for the P = S or P = O bond) is determined, which leads to the best agreement between calculated frequencies of the symmetrical vibrations and those experimentally found in the Raman effect assuming that d1 = d2 and that f1/d1 = f2/d3 = 13.6 as in P4O6. For P4O6S4, f2 = 5.5 × 105 dyne/cm is found. This value introduced into Badger's formula gives rp=s = 1.85 A, in excellent agreement with the experimental value. For P4O6O4, f2 = 11.0 × 105. A certain discrepancy does exist here between rP=O calculated (1.46 A) and the bond length found (1.39 A). Finally, the modes of motion of the atoms in the symmetrical vibrations of P4O6O4 were calculated and graphically represented. There is good agreement between the vibrational motions found and those assumed previously.

Journal ArticleDOI
TL;DR: In this paper, the ultraviolet absorption spectra of stilboestrol and p,p′-dihydroxystilbene were analyzed and it was concluded that the stilbrol molecule does not have a plane structure and that it is doubtful whether the explanation of the oestrogenic activity based on its often suggested "formal" similarity to the natural oestrogensic hormones is justified.
Abstract: Ultraviolet absorption spectra are recorded of cis- and trans- cinnamic acid, of cis- and trans-1,2,3,4,-tetrahydronaphthylidene (1) acetic acid and of cis- and trans-β-(naphthyl-1) acrylic acid. The cis isomers all show a lower extinction coefficient and a shift of the maximum of absorption to shorter wave-length in comparison with the trans isomers. It is concluded that as a result of steric hindrance in the case of the cis compounds the conjugation between aromatic ring system and carboxyl group is hindered, the molecules not possessing a plane structure. The fact that all these cis compounds show marked activity as plant growth promoter, whilst the trans isomers are totally inactive, is in accordance with the conclusions about their stereochemical structure. Comparison of the ultraviolet absorption spectra of stilboestrol and of p,p′-dihydroxystilbene leads to the conclusion that the stilboestrol molecule does not have a plane structure and that it is doubtful whether the explanation of the oestrogenic activity based on its often suggested „formal” similarity to the natural oestrogenic hormones is justified.

Journal ArticleDOI
TL;DR: In this paper, velocity measurements of the ozonisation of benzene, toluene, m-xylene, mesitylene and hexamethylbenzene were used to determine the order of the reaction.
Abstract: It appears from velocity measurements of the ozonisation of benzene, toluene, m-xylene, mesitylene and hexamethylbenzene that the reactivity of these substanees increases in the order mentioned. The order of the reaction could not be determined in the case of benzene, toluene and m-xylene. With mesitylene the reaction is apparently quatermolecular and with hexamethylbenzene it is apparently bimolecular. The results of comparative velocity measurements with mixtures of benzene and toluene are not in disagreement with direct velocity measurements.

Journal ArticleDOI
TL;DR: In this paper, the rates of deacylation of aromatic acylamino compounds having a nitro group in ortho- or para-position were investigated, with the aim of obtaining further (semi-) quantitative information with regard to steric effects on mesomerism.
Abstract: This paper is the first of a series dealing with an investigation of the rates of deacylation of aromatic acylamino compounds having a nitro group in ortho- or para-position, with the aim of obtaining further (semi-) quantitative information with regard to “steric effects on mesomerism” (“steric hindrance of resonance”). In the first section some remarks on the nomenclature have been made, more in particular on the use of the “neutral” word “effect”, rather than the more customary “hindrance”. Further, it has been pointed out that the so-called “Mills-Nixon effect” should be regarded as a special case of steric effects on mesomerism, viz. as a steric effect on mesomerism due to changes in valency angles. The mechanism of the deacylation has been discussed in some detail; the mesomerism in the ortho- or para-nitrophenylamino grouping is regarded to be mainly responsible for the “catalytic” deacylation. The question as to whether the slow deacylation observed in some cases might be caused by steric hindrance in the classical sense, rather than by steric effects on mesomerism, has been considered, the conclusion being that steric hindrance is certainly not of prime importance. In the last section the method by which the rates of deacylation are compared in order to get an insight into the magnitudes of the steric effects on the mesomerism, has been given and discussed briefly.

Journal ArticleDOI
TL;DR: In this paper, a theory is developed which connects the degree of swelling of a polymer network bearing ionogenic groups with the electrolyte concentration in the swelling medium, based on the assumption of an electrolyte distribution according to a Donnan equilibrium between the gel and the surrounding liquid.
Abstract: A theory is developed which connects the degree of swelling of a polymer network bearing ionogenic groups with the electrolyte concentration in the swelling medium. It is based on the assumption of an electrolyte distribution according to a Donnan equilibrium between the gel and the surrounding liquid on the one hand, and on the application of a modified Flory-Rehner equation to the dependence of the free energy of dilution on the degree of swelling on the other hand. This theory is applied to the swelling of cellulose xanthate gels in neutral salt solutions. The following conclusions are reached. 1 The theoretical relation between the degree of swelling q and the electrolyte concentration c has the form q5/3 = B/βλc + (1-K)/2 β, where B, β and K are constants related to fundamental physical properties of the swollen network; λ is a valency factor of the electrolyte studied. 2 In agreement with this formula the experimental q5/3- 1/λc plots are linear at moderate degrees of swelling and fairly independent of the electrolyte used. An explanation is given for deviations from linearity observed in highly swollen systems. From the slope of the experimental swelling curves it is concluded that the network consists of short chains. 3 Apart from the influence of the valency of the ions there exists also a lyotropic influence of the ions on the swelling of the gel. 4 The strong dependence of swelling on the xanthate ratio of the gel is in quantitative agreement with the effect predicted by theory.

Journal ArticleDOI
TL;DR: In this paper, le fait qu'on n'a pas pu realiser cette reaction chez une sulfone non saturee acyclique (allylbenzylsulfone) doit etre attribue a des conditions qui provoquent une addition du solvant.
Abstract: L'isomerisation des sulfones cycliques des butadienes consiste en un deplacement de la double liaison de la position β a la position α par rapport au groupe sulfonyle. Le fait qu'on n'a pas pu realiser cette reaction chez une sulfone non saturee acyclique (allylbenzylsulfone) doit etre attribue a des conditions qui provoquent une addition du solvant. A l'aide d'amines tertiaires, les auteurs ont reussi cette isomerisation. L'addition d'alcool, de phenol, en presence de leur derive sodique, et d'amines donne, dans chaque cas, un seul produit substitue en position β. Ces additions s'accomplissent probablement par l'intermediaire de la sulfone isomere (propenylbenzylsulfone), qui prend naissance en milieu nucleophile. L'addition de l'acide iodhydrique a l'allylbenzylsulfone donne deux isomeres, les iodures β et γ. Lorsqu'on chauffe le melange avec de l'ammoniac alcoolique, le β-iodure perd de l'acide iodhydrique en engendrant la propenylbenzylsulfone; le γ-iodure n'est pas decompose.

Journal ArticleDOI
TL;DR: The results of the theoretical considerations described in Part I are applied to experiments on chemical absorption of carbon dioxide in alkali hydroxide solutions and in ammoniacal solutions.
Abstract: The results of the theoretical considerations described in Part I are applied to experiments on chemical absorption of carbon dioxide in alkali hydroxide solutions and in ammoniacal solutions. The calculated values for the rate of absorption prove to be in good agreement with the experimental data.

Journal ArticleDOI
TL;DR: In this article, the authors present a methode d'analyse volumetrique de l'acide azothydrique and des azotures au moyen de permanganate de potassium, prealablement reduit par un sel de manganese bivalent en exces, en presence d'acides sulfurique and d'acidide phosphorique.
Abstract: Methode d'analyse volumetrique de l'acide azothydrique et des azotures au moyen de permanganate de potassium, prealablement reduit par un sel de manganese bivalent en exces, en presence d'acide sulfurique et d'acide phosphorique. L'exces de permanganate est dose avec d'iodure de potassium par titrage de l'iode libere au moyen de thiosulfate de sodium decinormal.

Journal ArticleDOI
TL;DR: In this paper, the preparation of 3-methyl-4-ethylpyridine, 3methyl- 4-n-propyl pyridine and 3methyl 4 n-butylpyride from 3methyl pyride is described.
Abstract: The preparation of 3-methyl-4-ethylpyridine, 3-methyl-4-n-propylpyridine and 3-methyl-4-n-butylpyridine from 3-methylpyridine, by the method of Wibaut and Arens, is described.

Journal ArticleDOI
K. Ter Haar1, W. Westerveld1
TL;DR: In this article, a colorimetric determination of nickel as dimethylglyoxime was given, but in contrast to the customary methods, use is made of persulphate as oxidizing agent.
Abstract: A description is given of a colorimetric determination of nickel as Ni(4) dimethylglyoxime, but in contrast to the customary methods, use is made of persulphate as oxidizing agent. The influence of other metallic ions has been investigated too. It appears that, of the elements investigated Ag must be removed, while the alkaline earth metals give a sulphate precipitate which can be removed by centrifuging. The determination of Ni in the presence of Mn, Fe, Cu and Co presents the greatest difficulties. In many cases we have succeeded finally in determining nickel in the presence of these elements without removing them. Thus it is possible to determine accurately 5% Ni and over in manganese, 0.25% and over in iron, 0.05% and over in copper and 0.05% and over in cobalt. In general it has been established that the highest accuracy is obtained when full attention is paid to the following points: (1)the avoidence of ammonia (2)the regulation of the amount of dimethylglyoxime (1)the acidity of the solution. If one of these points is not in order, the degree of accuracy becomes less. This is the case in the determination of Ni in the presence of cobalt, copper, in which case the presence of ammonia is a necessary condition for the formation of the colour. It can be remarked that this method is extensively applied in our laboratory in the determination of Ni in chrome-iron. Mo and W compounds.

Journal ArticleDOI
TL;DR: In this paper, the action of sodium phenate on 2,4,6-tribromopyridine has been investigated and the order in which the bromine atoms are replaced appeared to be dependent on the solvent used.
Abstract: The action of sodium phenate on 2,4,6-tribromopyridine has been investigated. The order in which the bromine atoms are replaced appeared to be dependent on the solvent used. In phenol the bromine atoms in positions 2 and 6 reacted first and then that in position 4; in water the rate of replacement of the 4 bromine atom had relatively increased, becoming even greater than that of the atoms in positions 2 and 6. The structure of the substances formed was proved by converting them into phenoxypyridines, the constitution of which was established by synthesis from mono- and dibromopyridines.

Journal ArticleDOI
TL;DR: In this paper, experiments were made on the influence of these compounds on monolayers of lecithin or oleic acid spread on aqueous solutions, and it was found that apparently plant growth substances penetrate into and accumulate in such monoline, their influence generally consisting in seemingly increasing the molecular area in the film.
Abstract: In connection with the hypothesis that plant growth substances do not exert their growth promoting activity by a chemical reaction proper (e.g. functioning as redox-catalysts) but by a more physical type of action on certain structures in the living cell1, experiments were made on the influence of these compounds on monolayers of lecithin or oleic acid spread on aqueous solutions. It was found that apparently plant growth substances penetrate into and accumulate in such monolayers, their influence generally consisting in seemingly increasing the molecular area in the film. In some cases (decahydro-naphthylacetic acid or undecanoic acid in the hypophases) very peculiar curves were obtained. The activity of a number of compounds tested in this way may be understood by considering the balance between the lipophilic part of the molecules and the hydrophilic carboxyl group. Although the type of action proved to be qualitatively as expected, a parallelism between the growth promoting activity of the compounds and their influence on these simple surface layers does not exist. Further detailed studies must provide an answer to the question whether the difference between the action in the model systems and in vivo might be caused by the apparently much too simple and aspecific composition of the films used, or whether, with the ideas put forward in1 , the physiological action has been simplified too much.

Journal ArticleDOI
TL;DR: In this article, les auteurs decrivent les reactions of Friedel-Crafts entre a serie of chlorures d'acides gras aliphatiques and le thionaphtene.
Abstract: Dans ce travail, les auteurs decrivent les reactions de Friedel-Crafts entre une serie de chlorures d'acides gras aliphatiques et le thionaphtene. De nombreuses cetones nouvelles ainsi que certains de leurs derives sont mentionnees a ce propos, et les analogies de comportement entre le thionaphtene et le naphtalene sont evoquees.

Journal ArticleDOI
TL;DR: In this article, the 3,5diethoxy-dinitropyridine was shown to be a mono-nitro-derivative with the nitro group in the 2-position.
Abstract: Konigs, Gerdes and Sirot have prepared a 3,5-diethoxy-dinitropyridine by nitrating 3,5-diethoxypyridine. On repeating this experiment we have obtained a mono-nitro-derivative. We have proved that in this compound the nitro group is introduced into the 2-position. When the 3,5-diethoxy-2-nitropyridine is nitrated further the dinitrocompound described by Konigs et al. is obtained. The nitro groups in this compound are in the 2- and 6-positions.

Journal ArticleDOI
TL;DR: The possible significance of the cinchoninic acid structure for chemical carcinogenesis is discussed in this article. But this work is limited to the case of 6-methyl-2,3-(fluoreno)2,1′-pyridine.
Abstract: 2-Aminofluorene condenses with pyruvic acid to yield the cinchoninic acid, 6-methyl-2,3-(fluoreno)2′,1′-pyridine-4-carboxylic acid. The compound is readily decarboxylated to 6-methyl-2,3-(fluoreno-2′1′)-pyridine]. The possible significance of the cinchoninic acid structure for chemical carcinogenesis is discussed.

Journal ArticleDOI
TL;DR: In this paper, the preparation of diethyldichlorosilane from silicon tetrachloride and ethylmagnesium bromide has been improved by using linear ethylsilazines which may contain chlorine atoms.
Abstract: Diethyldichlorosilane reacts with dry ammonia to give hexaethylcyclotrisilazine. Intermediates in this reaction are linear ethylsilazines which may contain chlorine atoms. The silazines decompose under the influence of moisture into NH3, diethylsilanediol and silicones. The preparation of diethyldichlorosilane from silicon tetrachloride and ethylmagnesium bromide has been improved.