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Versuche zur umsetzung von methylendiphenolen mit glucosederivaten und zur kondensation von O-phenylglucosidderivaten

1981

Attempts to apply known methods of glucosidation to oligo[(hydroxyphenylene)methylene]s were not satisfying. The reaction of 4,4'-dimethyl-2,2'-methylenediphenol (1a) with 2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyl bromide gave a monoglucoside in 11% yield. A second attempt, the condensation of suitable O-phenylglucoside derivatives was unsuccessful. From a series of O-phenylglucosides (4) only 4-(2,3,4,6-tetra-O-acetyl-α-D-glucopyranosyloxy)benzylbromide could be condensed with O-(4-hydroxymethylphenyl)-2,3,4,6-tetra-O-acetylglucopyranose to the corresponding diglucoside of 4,4'-oxydimethylenediphenol (7). Condensation reactions of the O-phenylglucoside 4k, to obtain an O-glucosidized poly[…

Studies on the synthesis of heterocyclic compounds. Part IV. Further investigation of the pschorr reaction with some pyrazole derivatives

1980

Thermal decomposition of the diazonium sulfate derived from N-methyl-(1-phenyl-3-methylpyrazol-5-yl)-2-aminobenzamide afforded products formulated as 1-phenyl-3-methyl[2]benzopyrano[4,3-c]pyrazol-5-one (yield 10%), 1,4-dimethyl-3-phenylpyrazolo[3,4-c]isoquinolin-5-one (yield 10%), N-methyl-(1-phenyl-3-methylpyrazol-5-yl)-2-hydroxybenzamide (yield 8%) and 4′-hydroxy-2,3′-dimethyl-1′-phenylspiro[isoindoline-1,5′-[2]-pyrazolin]-3-one (yield 20%). Decomposition of the diazonium sulfate derived from N-methyl-(1,3-diphenylpyrazol-5-yl)-2-aminobenzamide gave products formulated as 7,9-dimethyldibenzo[e,g]pyrazolo[1,5-a][1,3]-diazocin-10-(9H)one (yield 8%), 4-methyl-1,3-diphenylpyrazolo[3,4-c]isoqu…

Optische aktivität bei copolymeren aus (—)-acrylsäure-menthylester und styrol

1965

Die Copolymerisation von (–)-Acrylsaure-menthylester mit Styrol wurde untersucht. Die Copolymerisationsparameter betragen: r1 = 0,28 (Acrylsaurementhylester), r2 = 0,84 (Styrol); hieraus folgt fur Q = 0,45 und e = 0,40. Die spezifische Drehung der Copolymeren erwies sich bei 5 Wellenlangen als lineare Funktion des Acrylsaurementhylestergehaltes. Aus den Drehwerten kann daher die Zusammensetzung bestimmt werden; Ruckschlusse auf die Sequenzlangenverteilung sind aber nicht moglich. The copolymerization of (—)-menthyl acrylate with styrene was investigated. The reactivity ratios and the Q- and e-values were found to be: r1 = 0.28 (menthylacrylate), r2 = 0.84 (styrene); Q = 0.45, e = 0.40. The …

ChemInform Abstract: Nb4Te17I4, a New Pseudo One-Dimensional Solid-State Polytelluride.

2010

The new ternary compound Nb4Te17I4 has been prepared and structurally characterized. It crystallizes in the monoclinic system, space group C2/c with unit-cell parameters a = 16.199(4), b = 8.128(2), c = 27.355(6) A, β = 110.84(2)°, Z = 4. The structure consists of infinite one-dimensional niobium/tellurium chains running parallel to the crystallographic c direction. The chains are separated by iodine atoms. Short and long metal–metal distances alternate in the sequence of three consecutive short bonds ([d ≈ 3.1 – 3.2 A) and one long (d = 4.268 A) metal–metal separation. Each Nb atom is eight-coordinate. The composition of the chain is ∞11[(Nb5+)2(Nb4+)2(Te22−)4(Te32−)3(I−)4].

Über die zersetzung von hydroperoxyden durch katalase und durch lebereiweißfraktionen

1959

Es werden Herstellung und Eigenschaften einer Eiweisfraktion aus Rinderleber beschrieben, die auf Wasserstoffperoxyd, athyl-, Isopropyl- und tert.-Butylhydroperoxyd zersetzende Wirkung ausubt. Der fur das Zustandekommen der Zersetzungsreaktion der drei letzgenannten Peroxyde notwendige Acceptor wird als athanol identifiziert. Die Eiweisfraktion wird bezuglich ihrer Eigenschaften mit einer kristallisierten Katalase verglichen und aus dem Ergebnis der Schlus gezogen, das sie mit Katalase identisch ist. Als Reaktionsprodukt der enzymatisch katalysierten Reaktion zwischen tert.-Butylhydroperoxyd und athanol wurde Acetaldehyd nachgewiesen. The preparation and properties of an albumen fraction fr…

Polycondensed nitrogen heterocycles. Part25. Aminopyrrolo[1,2-f]-phenanthridines by decomposition of 2-(3-azidophenyl)-1-arylpyrroles

1994

Acid catalyzed decomposition of the azido derivatives 4a-c gave rise to amino-hydroxy-phenylpyrroles of type 7 and 8 upon hydrolysis of the intermediate aryl nitrenium ions, together with the hydrogen abstraction compounds of type 3. The aminopyrrolo[1,2-f]phenanthridines 10, 11, and 12 were obtained by treatment with TFMSA of the azide 4d in which the ring being attacked was made more nucleophilic by the introduction of the methoxy group.

ChemInform Abstract: Polycondensed Nitrogen Heterocycles. Part 25. Aminopyrrolo(1,2-f) phenanthridines by Decomposition of 2-(3-Azidophenyl)-1-arylpy…

2010

Acid catalyzed decomposition of the azido derivatives 4a-c gave rise to amino-hydroxy-phenylpyrroles of type 7 and 8 upon hydrolysis of the intermediate aryl nitrenium ions, together with the hydrogen abstraction compounds of type 3. The aminopyrrolo[1,2-f]phenanthridines 10, 11, and 12 were obtained by treatment with TFMSA of the azide 4d in which the ring being attacked was made more nucleophilic by the introduction of the methoxy group.

Protection of iron-based alloys likely to be exposed to corrosive atmospheres

1998

Summary This study examines the influence of temperature on oxidation kinetics of the alloys Z2CT 17 and Z4CN 18-09. A thin layer of aluminium oxide was laid down on these, using chemical, vapor deposition, in order to give improved protection.

Compositional analysis of styrene and maleic anhydride copolymerization: Complex model and penultimate model

1985

Potential energy surface for the decomposition of mandelic acid

1997

Abstract The decomposition of mandelic acid has been studied by ab initio calculations at the MP2/6-31G ∗∗ level. Three competitive reaction pathways have been characterized, two are stepwise processes with the formation of an α-lactone intermediate, achieved by the nucleophilic attack of either the carbonylic oxygen atom (mechanism A) or the hydroxylic oxygen atom (mechanism B) of the carboxyl group, followed by a ring opening; the third pathway (mechanism C) is a one-step process. The calculated rate coefficient agrees with experimental data. The decomposition is energetically favourable along mechanism A.