Synthesis of 2,3,7,8-tetramethyldibenzofuran

3,4,3,4-Tetramethyldiphenyl ether readily forms 2,2-dihalo derivatives on bromination and iodination. Heating 2,2-diiodo-4,5,4,5-tetramethyldiphenyl ether with copper powder or oxidation, of 2,2-dilithio-4,5,4,5-tetramethyldiphenyl ether gives 2,3,7,8-tetramethyldibenzofuran, the structure of which was proved by alternative synthesis from 2,2-dinitroand 2,2-diamino-4,5,4,5-tetramethyldiphenyls.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1597–1599, December, 1972.     

1,4-bis(4′-hydroxy-1′,2′,5′-trimethyl-4-piperidyl)-1,3-butadiyne and its derivatives

1.4-Bis(4-hydroxy-1,2,5-trimethyl-4-piperidyl)-1.3-butadiyne has been synthesized from the individual isomers of 4-ethynyl-1,2,5-trimethyl-4-piperidol. Hydrogenation, bromination, and cleavage have given, respectively, 1,4-bis(4-hydroxy-1,2,5-trimethyl-4-piperidyl)butane, 1,4-bis(4-nydroxy-1,2,5-trimethyl-4-piperidyl)-1,2,3,4-tetrabromo-1, 3-butadiene, and 4-(1,3-butadiynyl)-1,2,5-trimethyl-4-piperidol.     

Mono and dinuclear cationic rhodium(I) and iridium(I) complexes with sulphur donor and group Vb ligands

Summary Rhodium(I) and iridium(I) mixed complexes of the formulae [M(diolefin)LL]ClO₄, [M(diolefin)L₂L]ClO₄, [(diolefin)LIr(-L)₂IrL(diolefin)](ClO₄)₂, [(diolefin)LM(-L-L)ML'(diolefin)](ClO₄)₂, [(diolefin)Rh{-(L-L)}₂Rh(PPh₃)₂](ClO₄)₂ and [(diolefin)LIr{-(L-L)}₂IrL (diolefin)](C1O₄)₂, (L=monodentate sulphur ligand, L-L=bidentate sulphur ligand, L=group Vb ligand; M=Rh, diolefin=1,5-cyclooctadiene (COD) or 2,5-norbornadiene (NBD); M=Ir, diolefin=COD) are described.Author to whom all correspondence should be directed.     

Structure of some components of the roots of Prangos ferulacea

Summary From a methanolic extract of the roots ofPrangos ferulacea (L) Lindl., growing in the Nakhichevan ASSR, in addition to the compounds found previously, another six substances (I–VI) have been isolated, of which (I) and (VI) have been identified as, respectively, meransin hydrate monoacetate, found for the first time in nature, and umbelliferone: and in the study of a crystalline mixture obtained from the resin of the roots of the plant under investigation collected in Armenia, two coumarins — (VII) and (VIII) — have been isolated.On the basis of a study of IR, NMR, and mass spectra and chemical properties, the structures of the six new cumarin derivatives (II–V, VII, and VIII) have been established. Compound (II) has the structure of 8-(3-methylbutenyloxy)furo-2,3:7,6-coumarin and has been called feruliden; (III) is 7-hydroxy-8-(3-hydroxy-2-senecioyloxyisopentyl) coumarin and has been called ferudiol; (IV) is 7-hydroxy-8-(3-methoxy-2-senecioyloxyisopentyl) coumarin; (V) is 5-[1-(2,3-dihydroxy-3-methylbutyroyloxy)-1-methylethyl]-4,5-dihydrofuro-2,3:7,6-coumarin and has been called lindiol; (VII) is 8-(2-hydroxy-3-methylbut-3-enyloxy)-7-methoxycoumarin and has been called ferudenol; (VIII) is 7-methoxy-8-(3-methyl-2-oxobut-3-enyl)coumarin and has been called prangone.Leningrad Sanitary-Hygenic Medical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 568–574, September–October, 1974.     

Synthesis and characterization of some methyl complexes of palladium(II). Part 2(1)

Summary Dichloro complexes of Pd^II, [Pd(L–L)Cl₂], where L–L=1-(thiomethyl)-2-(diphenylarsino)ethane (S–As) or 1-(thiomethyl)-2-(diphenylphosphino)ethane (S–P) andtrans-[PdL₂Cl₂], where L=diphenyl(2-phenylethyl)-phosphine (PE), diphenyl(1-naphthyl)phosphine (PN) orN-methyl-2-thiophenealdimine (SN), have been prepared and characterized. The reactions of these complexes with MeLi were investigated. The dimethyl complexes [Pd(L–L)Me₂] (L–L=S–As, S–P) and [Pd(PE)Me₂] were isolated and characterized. Reaction of [Pd(L–L)Me₂] (L–L=S–As, S–P) with HCl affords the monomethyl derivatives [Pd(L–L)Me(Cl)]. In contrast to the Pt analogues, [Pd(L–L)Me₂] and [Pd(L–L)Me(Cl)] are relatively less stable than [Pt(L–L)Me₂] and [Pt(L–L)Me(Cl)].     

Synthesis of novel heterocycles from thiazolecarbohydrazides

Cyclization of 2-methyl (or -phenyl)-5-phenylthiazole-4-carbohydrazides (1) and (2) under various conditions gives differing oxadiazoles: 2-(2-substituted-5-phenyl-4-thiazolyl)-1,3,4-oxadiazole-5-thiones (7) and (8), and 2-(2-substituted-5-phenyl-4-thiazolyl)-1,3,4-oxadiazoles (9) and (10). Cyclodehydration of thiazolecarbonyl-thiosemicarbazides (3)–(6) with NaOH givesthe 3-(2-substituted-5-phenyl-4-thiazolyl)-4-substituted-4H-5-mercapto-1,2,4-triazoles (11)–(14), while H ₃ PO ₄ gives the 2-(2-substituted-5-phenyl-4-thiazolyl)-5-phenylamino-1,3,4-thiadiazoles (15) and (16).A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan Science Center, Russian Academy of Sciences, 420083 Kazan'. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 3, pp. 679–683, March, 1992.     

Cobalt(II) and nickel(II) chloride and bromide complexes of 2-(2′-methyl-8′-quinolyl)benzoxazole and 2-(2′ or 4′-methyl 8′-quinolyl)benzimidazole

Summary Cobalt(II) and nickel(II) halide complexes of the ligands 2-(2-methyl-8-quinolyl)benzoxazole (mqbo), 2-(2-methyl8quinolyl)benzimidazole (mqbi) and 2-(4-methyl-8-quinolyl)benzimidazole (mqbi) were synthesized and characterized by analytical, thermogravimetric, conductivity and magnetic data, and i.r. and electronic spectra.The ligands are bidentate N-donors yielding complexes where the coordination geometry depends on the metal ion and steric hindrance. All the cobalt complexes have formula [CoL₂X₂] and distorted tetrahedral geometry. Different types of nickel compounds were obtained: i) complexes of formula NiLX₂ · n H₂O (or EtOH) (L = mqbo or mqbi; n=0–1.5) which arepseudo-tetrahedral or five-coordinate and ii) complexes NiL₂X₂ · n H₂O (L = mqbi, n=3 or 4) where the metal is bound to four nitrogen atoms and the overall coordination geometry is tetragonal. The structural changes occurring after removal of water or alcohol from the complexes are also reported.     

Temperature programmed desorption of NH3 and H2O from NH4NaX and CoNH4NaX zeolites

A study has been made of temperature programmed desorption (TPD) of NH₃ and H₂O from samples of NH₄X and CoNH₄X zeolites of various degree of exchange. NH₃ TPD peaks could be explained by interaction of NH₃ with different Brönsted and Lewis acidic centers. Moreover a water peak at high temperatures allowed interpretations of the dehydroxylation, and by reason of the characteristic desorption temperatures a particular state of the Co²⁺ ions in the CoNH₄X zeolites is postulated.

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- () NH₃ H₂O NH₄X CoNH₄X . NH₃ NH₃ =qs . . Co²⁺ CoNH₄X.

     

Coke deposition on naphtha reforming catalysts: II. Influence of the addition of a second metal to platinum

The nature and rate of coke deposited on mono-and bimetallic reforming catalysts have been studied for normal heptane reforming. For bimetallic catalysts it has been shown that coke deposition is less extensive than on monometallic catalyst, depending on the degree of polymerization and the type of bimetallic catalyst.

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-. , , , .

     

Investigations in the field of the chemistry of 2-hetarylbenzimidazoles. 6. Synthesis and properties of 1-methyl-2-(2′-selenienyl)benzimidazole

2-(2-Selenienyl)benzimidazole has been synthesized by a Weidenhagen reaction and converted into the N-methylated derivative. Electrophilic-substitution reactions (nitration, sulfonation, bromination, chloromethylation, and acylation) in the selenophene ring have been studied. It has been shown that the substituent enters the position of the selenophene ring in most cases. The bromination of 1-methyl-2-(2-selenienyl)benzimidazole in acetic acid produces the 3,5-dibromo derivative, whereas 1-methyl-5(or 6)-bromo-2-(3,5-dibromo-2-selenienyl)benzimidazole is obtained in polyphosphoric acid.For Report 5, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1531–1534, November, 1983.     

Isoflavones of the roots of Lupinus luteus

Conclusions For the first time in the isoflavone series, a compound which has the structure of 5,7-dihydroxy-3,4-methylenedioxyisoflavone (3,4-methylenedioxyorobol) and two of its glucosides — 3,4-methylenedioxyorobol 7-O--D-glucoside and 3,4-methylenedioxyorobol 7-O--D-glucosylglucoside — and also a genistein C-monoglucoside, have been described. The isoflavones were isolated from the roots ofLupinus luteus L. by preparative chromatography on paper and on columns of polyamide. In addition, the previously known genistein, genistein 7-O--D-glucoside (genistin), and genistein 7-O--D-glucosylglucoside have been obtained.V. F. Kuprevich Institute of Experimental Botany, Academy of Sciences of the Belorussian SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 162–166, March–April, 1974.     

Synthesis and structure of o-bis(2-fluoro-2,2-dinitroethyl)-nitromethyl ester of 2′-fluoro-2′, 2′-dinitroethyl-2″-fluoro-2″-nitroethylenecarboxime

Conclusions The product of conversion of O-bis(2-fluoro-2,2-dinitroethyl)nitromethylbis(2-fluoro-2,2-dinitroethyl)carboxime in methanol or ether is O-bis(2-fluoro-2,2-dinitroethyl)nitromethyl-2-fluoro-2,2-dinitroethyl-2'-fluoro-2-nitroethylenecarboxinie, the structure of which has been established by x-ray diffraction analysis.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2019–2021, September, 1987.     

Thermal properties of elastin-fatty acid complexes

Differential scanning calorimetry has been applied to study the interaction of fibrous or of soluble elastin with fatty acids and their trialanine derivatives. The DSC curves of elastin-fatty acid preparations exhibited an endothermic transition in the temperature range - 10° to + 50°. The peak temperatures and the enthalpy changes were independent of the chain length and of the saturation of the fatty acid. The interaction with the trialanine derivatives was similar to that with the fatty acids.Such interactions between elastin and lipids might take place in vivo as well, resutling in the loss of elasticity of elastin fibres and consequently in the development of arteriosclerotic lesions.

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Zusammenfassung Zur Untersuchung der Wechselwirkung zwischen dem fibrösen oder lösbaren Elastin, und den Fettsäuren und ihren Trialanin-Derivaten wurde die DSC-Methode angewandt. Die DSC-Kurven der Elastin-Fettsäure-Präparate zeigten in dem Temperaturbereich von - 10° bis + 50° einen endothermischen Übergang. Die Peak-Temperaturen und die Änderungen der Enthalpie waren von der Kettenlänge und der Sättigung der Fettsäure unabhängig. Die Wechselwirkung mit den Trialanin-Derivaten war der mit den Fettsäuren ähnlich.Solche Wechselwirkungen zwischen Elastin und den Lipiden können auch in vivo stattfinden, und die Abnahme der Elastizität der Elastin-Fibern, und folglich die Entfaltung der arteriosklerotischen Schädigungen resultieren.

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. - — — 10° - + 50°. , . , . , , .

     

Synthesis and some properties of the methyl ester and N,N-diethylamide of 2-azido-5-phenyl-4-thiazolecarboxylic acid

The methyl ester and N,N-diethylamide of 2-azido-5-phenyl-4-thiazolecarboxylic acid were obtained by the reaction of the corresponding 4-substituted 2-hydrazino-5-phenylthiazole with NaNO₂ in acid media. IR and UV spectroscopy were used to show that the compounds synthesized retain azide form in both the crystalline state and in solution. The reaction of azides with dicarbonyl compounds gave derivatives of 2-[5-methyl-4-acetyl-or 2-[5-methyl-4-ethoxycarbonyl-1,2,3-triazol-1-yl]-5-phenylthiazole-4-carboxylic acid.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 710–714, May, 1993.     

Thermal research of montmorillonite synthetized from the oxides SiO2-Al2O3-MgO-CaO

The thermal behaviour of synthetic montmorillonite of relatively simple chemical composition has been studied and interpreted. Montmorillonite was prepared by hydrothermal synthesis at 300° and 8.8 MPa during 165 hours. With the methods of DTA, DTG, TG, X-ray diffraction analysis, infrared spectroscopy and electron microscopy it was proved that the synthetic montmorillonite is a monomineral sample and no differences from natural montmorillonite were observed.

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Zusammenfassung Das thermische Verhalten synthetischer Montmorillonite verhältnismässig einfacher chemischer Zusammensetzung wurde untersucht und gedeutet. Montmorillonit wurde durch hydrothermische Synthese bei 300°C und 8.8 MPa in 165 Stunden hergestellt. Durch die Methoden der DTA, DTG, TG, Röntgendiffraktionsanalyse, Infrarotspektroskopie und Elektronenmikroskopie wurde erwiesen, daß synthetische Montmorillonit eine monominerale Probe ist und keine Abweichungen von natürlichem Montmorillonit beobachtet werden konnten.

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. 165 300° 8.8 . , , , , , .

     

Thermal decomposition of CaCO3 in the presence of calcium fluoride

The thermal decompositoon of calcium carbonate mixed with calcium fluoride was examined by means of simultaneous TG, DTG and DTA. The temperature range of CaCO₃ decomposition shifted to higher temperatures as a result of CaCO₃-CaF₂ eutectic formation. The temperature of melting of this eutectic was in the temperature range of CaCO₃ decomposition, and therefore all factors which increase the partial pressure of CO₂ (such as the thickness of the sample layer, the shape of the crucible, the heating rate, etc.) influence the amount of the liquid phase. The DTA curves can be regarded as the sum of three endothermic effects occurring almost simultaneously: decomposition of CaCO₃ in the solid phase, melting of the eutectic, and decomposition of CaCO₃ present in the liquid phase.

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Zusammenfassung Die thermische Zersetzung von Calciumcarbonat-Calciumfluorid-Mischungen wurde durch simultane TG-DTG-DTA untersucht. Der Bereich der CaCO₃-Zersetzung wird infolge der Bildung des CaCO₃-CaF₂-Eutektikums zu höheren Temperaturen verschoben. Die Schmelztemperatur dieses Eutektikums liegt im Temperaturbereich der CaCO₃-Zersetzung, deshalb haben alle Faktoren, die den Partialdruck des CO₂ beeinflussen (Schichtdicke der Probe, Tiegelgeometrie, Aufheizgeschwindigkeit usw.) auch Einfluss auf die Menge der entstehenden flüssigen Phase. Die DTA-Kurven entstehen durch Überlagerung von 3 endothermen Effekten, die fast gleichzeitig ablaufen: Zersetzung von CaCO₃ in fester Phase, Schmelzen des Eutektikums, Zersetzung von CaCO₃ in flüssiger Phase.

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, . , CaCO₃-CaF₂. , ₂ ( , , .) . : , , .

     

Thermal and spectroscopic characterization of several derivatives containing a new organic ring system

Several derivatives containing a new organic ring system, the tropane-6-spiro-5-hydantoin structure (namely 8-alkyl-8-azabicyclo [3.2.1.] octane-6-spiro-5-imidazoline-2,4-diones) have been characterized by thermal (DSC and simultaneous DTA-TG-DTG) and spectroscopic techniques (IR,¹ H-NMR,¹³ C-NMR). X-ray powder diffraction and elemental analysis were applied for structural and molecular characterization. All the compounds melt in the range 160–250°C and undergo decomposition with progressive mass loss after the solid-liquid thermal transition with molecular degradation. It was found that tropane-6-spiro-5-hydantoin derivatives with the hydantoin ring in position are thermally less stable than those containing this ring in position.One of the authors (Dr. M.V.) thanks partial financial support from CICYT through research project PA 86-0317. Thanks are extended to Ms. A. García and Mr. J. C. Rivero for artwork.     

The structure of smyrnioridin

Conclusions A new coumarin, which has been called smyrniodidin, has been isolated from the roots ofSmyrniopsis aucheri acetoxy-1-methylethyl)-4-angeloyloxy-4,5dihydrofuro-2, 3: 7, 6-coumarin. Boiss. The NMR spectrum and a study of the saponification products of smyrnioridin have shown that it is 5-(1-