Synthesis of 2-amino-3-(ω-aminoalkyl)indoles

2-Amino-3-(-phthalimidoalkyl)indoles have been obtained by the rearrangement of -phthalimido acid -phenylhydrazides under the action of POCl₃. The possibility has been studied of eliminating the phthalyl protective group from these compounds and a convenient method has been developed for obtaining 2-amino-3-(-aminoalkyl)indole dihydrochlorides. The behavior of the 2-amino-3-(-phthalimidoalkyl) indoles in alkylation reactions has been investigated.Deceased.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 484–488, April, 1980.     

Diffusion Sensor of Mechanical Signals: Frequency Response at High Frequencies

The frequency response of a diffusion transducer with gauze electrodes, studied theoretically at high frequencies, is proportional to ^-3/2 starting with = D/R ² at < /R ² and to ^-1 at > /R ². Here, = 2f, f is the signal frequency, the electrolyte viscosity, D a diffusion coefficient, and R the radius of the gauze filaments. The calculation is compared with experiment.     

Détermination de la pureté de la sulfapyridine s par analyse thermométrique

Résumé L'étude thermoanalytique de la pureté de deux échantillons de sulfapyridine, médicament (I) et standard (II), a été réalisée par différentes méthodes. Par mesure de la transparence les valeurs moyennes de la température et du domaine de fusion indiquent une teneur en impureté plus faible pour (II) que pour (I). Disposant de deux analyseurs thermiques de conception différente, les auteurs ont montré l'excellente concordance des résultats: 99.790 ± 0.047 % et 99.800 ± 0.045 % (I). Seule l'analyse calorimétrique différentielle permet d'évaluer avec précision le taux de pureté de (II) 99.956 ± 0.028 %, valeur représentant un seuil pour l'analyse calorimétrique différentielle à compensation de puissance (DSC 1B).

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The thermoanalytical purities of two sulfapyridine samples, drug (I) and standard (II), have been studied with different methods. By transparency measurement the fusion temperatures and intervals indicate a lower percentage of impurity for (II) than for (I). By means of two thermal analyzers the authors have shown the good agreement of the results: 99.790±0.047% and 99.800±0.045% (I). Heat-flux differential scanning calorimetry is the only method able to give precisely the degree of purity of (II): 99.956±0.028 %, this value being a limit for the power-compensation differential scanning calorimetry analysis (DSC 1B).

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Zusammenfassung Das Studium der thermoanalytischen Reinheit der beiden Sulfapyridinproben drag(I) und standard(II) wurde durch verschiedene Methoden durchgeführt. Schmelztemperaturen sowie-bereiche zeigen im Falle von Transparenzmessungen einen geringeren Prozentsatz von Verunreinigungen für (II) als für (I). Unter Anwendung zweier Thermoanalyser zeigten die Autoren die gute Übereinstimmung der Ergebnisse: 99.790±0.047% und 99.800 ± 0.045 % für (I). Ein Wärmeströmungs-Differentialabtastkalorimeter bietet die einzige Möglichkeit den Reinheitsgrad von (II) genau zu bestimmen: 99.956 ± 0.028 %, wobei dieser Wert die Grenze für die Kraft-Kompensations-Differentialkalorimetrie (DSC 1B) darstellt.

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: (I) (II). , , II , I. , : 99.790±0.047% 99.800 ± 0.045% I. II: 99.956 ± 0.028% ( 1).

     

Third-Order Nonlinear Optical Response of a New PVA Composite with PbS Nanocrystals

High third-order nonlinear optical susceptibility (⁽³⁾(;, –,)=3.4·10 ^–16 m²/V²) in the visible spectral range may be achieved in PVA composites with narrow-gap PbS semiconductor nanocrystals with a large exciton diameter.     

Fluorescent-labeled derivatives of dolichyl phosphate. Analogs of dolichyl phosphate with the 2-aminopyridine residue at the ω-end of the chain*

A simple approach to the synthesis of dolichyl phosphate derivatives with a fluorescent label, 2-aminopyridine residue, at the -end of the chain was developed. The method includes selective van Tamelen epoxidation of the -isoprene unit in dolichyl acetates, transformation of the epoxides to -terminal aldehydes, their reductive amination, and phosphorylation of the resulting amino alcohols.     

Thermische Zersetzung des Kaliumhexacyanoferrats (II)

Zusammenfassung Es wurde festgestellt, daß unter Luftzutritt die Grenze der thermischen Beständigkeit des K₄[Fe(CN)₆] bei 200° liegt. Die Zersetzung des Komplexes führt im Temperaturbereich von 200° bis 350° zu ferromagnetischen Intermediären. Der Ferromagnetismus der erwärmten Präparate konnte mit der Bildung von-Fe₂O₃ erklärt werden. Bei 250° besteht die vorherrschende kristalline Phase aus Kaliumkarbonat.

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It has been found that the limit of thermal stability of K₄[Fe(CN)₆] in air is 200°. The decomposition of the complex in the temperature range of 200°–350° leads to ferromagnetic intermediates. The ferromagnetism of these products could be explained by the formation of-Fe₂O₃. At 250° the crystalline phase consists mainly of potassium carbonate.

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Résumé On a établi que la limite de la stabilité thermique de K₄[Fe(CN)₆] en présence d'air s'élève à 200°. Entre 200 et 350°, la décomposition du complexe donne des produits intermédiaires ferromagnétiques. Ce ferromagnétisme s'explique par la formation de-Fe₂O₃. A 250°, la phase cristalline dominante est constituée par du carbonate de potassium.

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, K₄[Fe(CN)₆] , 200°. 200°–350° . -Fe₂O₃. 250° .

     

Alkylation of oxypurines by α,ω-dihaloalkanes 1. Reaction of xanthine sodium salts and some N-methyl derivatives with α,ω-dihaloalkanes

A method was developed for obtaining previously unknown 1,3,7-tris(-haloalkyl)-, 1,7-bis(-chloroalkyl)-3-methyl-, and 1,3-bis(-chloropentyl)-7-methylxanthines.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya No. 9, pp. 2102–2105, September, 1989.     

Ammoxidation of propylene over SnO2?Sb2O4 mixed oxide catalysts doped with Ga, In or Tl

In studying the catalytic activities of SnO₂–Sb₂O₄ (SnSb=11) mixed oxides doped with Ga, In or Tl in the ammoxidation of propylene, a selectivity improvement was observed when the dopants Ga₂O₃ and Tl₂O₃ were used in low concentrations. At higher concentrations and for In₂O₃ the characteristics of the dopant prevail, disclosing that the admixed oxides are not evenly distributed in the bulk, but that the doping is rather confined to the surface layers of the catalyst.

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, Ga, In Tl 673 . , Ga₂O₃ Tl₂O₃ (0,5–2 . %). In₂O₃ . , , .

     

Simple Estimations of Dynamic Polarizabilities and Dispersion Coefficients Using the Spectral Moment Method

A modification of the spectral moment technique is suggested to calculate the frequency-dependent polarizabilities (i ) and ( ) and the corresponding dispersion constants. Unlike the previous schemes, this method uses the spectral moments S _q with positive values of q. Both variational and nonvariational methods are tested. An effective nonvariational procedure is worked out which isolates a regular (odd) component from the Brown–Rebane functional for (i ). Fast convergence to exact values is achieved by using a suitable renormalization of the electron transition pseudospectrum. The method is illustrated by the semiempirical and ab initio calculations of molecular systems of various classes.     

Concerning the enantiomerization barrier of hypericin

Summary The Syntheses of -(R)-menthyl and ,-bis-(R)-menthyl derivatives2 and3 of hypericin were achieved, and the corresponding diastereomers could be separated. The equilibria between the respective diastereomers are slightly displaced in favor of the chromatographically faster moving ones. Kinetic measurements on these easily equilibrating diastereomers of2 and3 provided anArrhenius activation energy for the interconversion barrier between the two propeller conformers of 83 and 89 kJ/mol. It could be shown that the -menthyl residues are of minor relevance to the height of this barrier, as is also the case for thebay hydroxyl ionization and quinone tautomerization equilibria. It was thus concluded that the intrinsic barrier for the propeller conformer enantiomerization of hypericin is in the order of 80 kJ/mol. These results are in accord with those obtained from semiempirical calculations.

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Zur Enantiomerisierungsbarriere von Hypericin

Zusammenfassung Nach Synthese der -(R)-Menthyl- und ,-bis-(R)-Menthylderivate2 und3 des Hypericins konnten die entsprechenden Diastereomerenpaare getrennt werden. Die Gleichgewichte sind etwas zugunsten der chromatographisch rascher wandernden Diastereomeren verschoben. Kinetische Messungen an diesen leicht äquilibrierenden Diastereomeren von2 und3 führten zu einerArrheniusschen Aktivierungsenergie für die Interkonversionsbarriere zwischen den beiden Propellerkonformeren von 83 und 89 kJ/mol. Es konnte gezeigt werden, daß die -Menthylreste für die Höhe dieser Barriere nur geringfügige Bedeutung haben, ebenso wie dasbay-Hydroxyl-Ionisierungsgleichgewicht und das Tautomeriegleichgewicht. Daraus wurde geschlossen, daß die intrinsische Barriere für die Enantiomerisierung der beiden Hypericinpropellerkonformeren in der Größenordung von 80 kJ/mol liegt. Dieses Resultat stimmt mit den Ergebnissen semiempirischer Rechnungen überein.

     

Synthesis of 1-Methyl and 1-Benzyl 3,5-Bis(ω-Mercaptoalkyl) Isocyanurates

1-Methyl and 1-benzyl 3,5-bis(-haloalkyl) isocyanurates were reacted with thiourea to obtain 1-methyl and 1-benzyl 3,5-bis[-[amino(imino)methylmercapto]alkyl] isocyanurates, respectively. Hydrolysis of the latter gave the corresponding 3,5-bis(-mercaproalkyl) izocyanurates.     

Anodic Dissolution of Armco Iron in a Mixed Kinetics Mode: Effect of Macroscopic Heterogeneity

Dependence of the current density of dissolution of an RDE made of Armco iron on the solution agitation rate is studied. Experiments are performed in weakly acid nitrate solutions of pH 1 containing 1–3 M of nitrate ions, at different charges passed, in a prepassive region. On the basis of these dependences, the effect the macroscopic heterogeneity (accumulation of passive phase of iron carbide Fe₃C during dissolution) exerts on the dissolution is analyzed. The anomalous behavior of the dissolution rate (which increases with decreasing rotation rate of RDE in a certain interval) is due to transition from a mixed diffusion–kinetic control of dissolution rate at a macroscopically heterogeneous electrode to a diffusion control, when the salt film that forms during dissolution screens the heterogeneity (passive areas). Heterogeneity parameters under mixed control may quantitatively be analyzed at high , if at low one observes a diffusion dissolution connected with a complete surface coverage by the formed salt film.     

Nitrosation of 4-amino-1-phenacyl-1,2,4-triazolium bromides and ω-(1,2,4-triazol-1-yl)acetophenones

The reaction of 4-amino-1-phenacyl-1,2,4-triazolium bromides with an excess of nitrous acid leads to a mixture of the corresponding -(1,2,4-triazol-1-yl)-acetophenones and -hydroximino--(1,2,4-triazol-1-yl)acetophenones. Products of the latter type are formed during nitrosation at the methylene group of both the intermediate -triazolylacetophenones, and the starting 4-amino-1-phenacyl-1, 2,4-triazolium bromides. The role of Br^– as a catalyst is significant for both nitrosation paths. In the reaction of -(1,2,4-triazol-1-yl)acetophenones with HNO₂, SCN^– is a more active catalyst than Br^–. During the nitrosation of para-substituted 4-amino-1-phenacyl-1,2,4-triazolium bromides, the yield of -hydroximino--(1,2,4-triazol-1-y1)acetophenones increases with increase in the acceptor properties of the aryl substituent, which is explained by the increase in the CH-acidity of the nitrosation substrates.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2821–2824, December, 1991.     

Synthesis of modified amino acids containing nucleic acid purine bases

The reaction of hydrazides of adenylyl- or hypoxanthinyl-9-alkylcarboxylic acids with sodium nitrite in acid media gives reactive azides of purinyl-9-alkylcarboxylic acids which condense with ()-aminocarboxylic and ,-diaminocarboxylic acids to give N(N)-(adenylyl-9-alkanoyl) aminocarboxylic, N-(adenylyl-9-)- and N-(hypoxanthinyl-9-alkanoyl)-,-diaminocarboxylic acids. The deamination of N-(adenyl-yl-9-alkanoyl)aminocarboxylic acids gives N-(hypoxanthinyl-9-alkanoyl)aminocarboxylic acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 126–130, January, 1985.     

The synthesis of ω-thienylalkane acids from ω-chloroalkane acids

Summary We have worked out a preparative method for the synthesis of -thienylalkane acids by acylation of thiophene with -chloroalkane acid chlorides followed by conversion of the resulting -chloroalkyl(2-thienyl)ketones into the corresponding acids by reaction with sodium malonic ester or potassium cyanide, and reduction of the resulting products with their simultaneous hydrolysis.Here and later we mean -(2-thienyl)alkne acids.We take this opportunity to thank R. Kh. Freidlina, A. A. Beér, and M. A. Besprozvannii for giving us enough -chloroalkane acids.     

On the synthesis of ω-appended hypericin derivatives

Summary A method for the preparation ofbis--appended hypericin derivatives bearingn-octyl,n-hexadecyl, and 2-(2-(2-hydroxyethoxy)-ethoxy)-ethoxymethyl substituents was developed. The key step — the synthesis of appropriately -substituted emodin derivatives — was achieved by solvolyzing 3-bromomethyl-1,6,8-triacetyloxy-anthracene-9,10-dione (-bromo triacetylemodin) in an appropriate alcohol in the presence of silver perchlorate. The correspondingbis--substituted hypericins were then prepared conventionally by dimerizing the -substituted emodin anthrones. The latter were prepared by reduction of the -appended emodins.

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Zur Synthese von -substituierten Hypericinderivaten

Zusammenfassung Eine Methode zur Darstellung vonbis--substituierten Hypericinderivaten wurde entwickelt. Der Schlüsselschritt — die Synthese der entsprechenden Emodinderivate — wurde durch die Solvolyse von 3-Bromomethyl-1,6,8-triacetyloxyanthracen-9,10-dion (-Bromtriacetylemodin) im entsprechenden Alkohol in Gegenwart von Silberperchlorat ermöglicht. Die entsprechendenbis--substituierten Hypericinderivate wurden auf konventionelle Weise durch Dimerisierung der -substituierten Emodinanthrone dargestellt. Letztere erhielt man durch Reduktion der -substituierten Emodine.

     

Liquid chromatographic studies for essential fatty acids on a commercial alkyl phenyl bonded silica column

Summary Retention studies on arachidonic acid 5, 8, 11, 14 all cis eicosatetraenoic acid, C20:46), eicosapentaenoic acid (5, 8, 11, 14, 17 all cis eicosapentaenoic acid, C2053) and docosahexaenoic acid (4, 7, 10, 13, 16, 19 all cis docosahexaenoic acid C2263) were performed on a commercial Bondapak free fatty acid analysis column. The ternary mobile phase consisting of acetonitrile, water and tetrahydrofuran was used in an isocratic mode with differential refractometry detection. Retention data were mesured at various flow rates with two different, mobile-phase compositions. Capacity factors and enthalpy of adsorption were calculated from the retention data. Finally the retention mechanism is explained.     

Synthesis of unsaturated ω-dimethylamino ketones

Conclusions We have examined the condensation of 1,1,3-trimethoxy-3-dimethylaminopropane with cyclic and heterocyclic ketones and with enaminoketones; we have synthesized a series of unsaturated-dimethylamino and,-bis(dimethylamino) ketones, which the PMR spectra indicate as having the trans configuration of the methine protons and to exist as the S-trans conformers about the, -bond.Translated from Izvestiya Akademii Nauk SSSR, No. 1, pp. 116–122, January, 1978.     

Reaction of the sodium salts of several hydroxypyrimidines withα,ω-dihaloalkanes

Conclusions A simple one-step method for the synthesis of 1,3-bis(-haloalkyl)uracils by reacting the Na salts of uracil and its derivatives with ,-dihaloalkanes has been developed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 880–884, April, 1977.