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  • 1965-1969  (4,978)
  • 1890-1899  (2,182)
  • Organic Chemistry  (5,311)
  • Physics  (1,849)
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  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 727 (1969), S. 219-221 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Diazocarbonyl Compounds, XXXI V I ). o-Quinone Diazides and o-Quinones as Dehydrobenzene InterceptorsSuitably substituted o-quinone diazides can be used to intercept arynes with simultaneous N2-elimination and formation of dibenzofuranes. o-Quinones add arynes in a Diels-Alder synthesis to form cyclic diketo compounds, which react with o-phenylenediamine to give the corresponding quinoxalines.
    Notes: Arine lassen sich mit geeignet substituierten o-Chinondiaziden unter N2-Abspaltung und Bildung von Dibenzofuranen abfangen. o-Chinone addieren nach Diels-Alder Arine zu cyclischen Diketo-Verbindungen, die mit o-Phenylendiamin zu den entsprechenden Chinoxalinen kondensieren.
    Additional Material: 3 Tab.
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  • 2
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 231-233 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidative Degradation of 5,6-DimethylbenzimidazolePrior to carrying out tracer experiments used in the investigation of the biosynthesis of 5,6-dimethylbenzimidazole (1) methods for its degradation had to be worked out. In order to identify all C-atoms, 1 had to be degraded by two procedures: The Kuhn-Roth degradation yields acetic acid and CO2. The acetic acid undergoes Schmidt degradation thus allowing the identification of C-5, C-6, and the methyl groups of 1. - The oxidation of 1 with K2Cr2O7 yields imidazole-4,5-dicarboxylic acid (4) which after decarboxylation gives imidazole and CO2. Thus C-2, C-8, and C-9 on the one hand and C-4 and C-7 on the other hand can be identified.
    Notes: Für Tracerversuche zur Biosynthese von 5.6-Dimethyl-benzimidazol (1) wurde 1 oxydativ abgebaut. Die Identifizierung sämtlicher C-Atome gelingt nur durch Abbau nach zwei Methoden: Der Kuhn-Roth-Abbau führt zu Essigsäure und CO2. Durch anschließenden Schmidt-Abbau der Essigsäure können C-5, C-6 und die Methyl-Gruppen von 1 identifiziert werden. - Die Oxydation mit Kaliumdichromat führt zu Imidazol-dicarbonsäure-(4.5) (4), deren Decarboxylierung zu Imidazol und CO2 die Identifizierung von C-2, C-8 und C-9 bzw. C-4 und C-7 erlaubt.
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  • 3
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 728 (1969), S. 49-55 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Molecular Structure Changes in Chemical Reactions, XXI 1 ). Deamination in the Bicyclo[2.2.l]-heptane SeriesThe deamination of bornyl- and fenchylamines is studied by gas chromatography. In contrast to norbornylamines the exo and endo compounds behave differently. A Wagner-Meerwein rearrangement is the main reaction in both cases. The resulting tertiary alcohol in the fenchane series is stereochemically mixed. Ring opening is considerable with endo amines but only slight with exo amines. The results are compared with those of the solvolysis in methanol of the corresponding tosylates.
    Notes: Die Desaminierung der Bornyl- und Fenchylamine wird gaschromatographisch untersucht; die im Gegensatz zu den Norbornylaminen bestehenden Verschiedenheiten von exo- und endo- Form werden festgelegt. Die Hauptreaktion ist allerdings in beiden Fällen eine Wagner-Meerwein-Umlagerung. Der entstehende tertiäre Alkohol in der Fenchan-Reihe ist sterisch nicht einheitlich. Eine Ringspaltung tritt bei den endo-Aminen erheblich, bei den exo-Aminen minimal ein. Die Ergebnisse werden mit denen der Methanolyse der entsprechenden Tosylate verglichen.
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 119-123 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Azobarbituric Acid arid Alloxan AzineAzobarbituric acid (2) is formed as a by-product of the reaction between barbituric acid and carbamoylazide (H2NCON3), the main product being 5-aminocarbonylbarbituric acid. It is easily dehydrogenated by bromine water to give alloxan azine (3) which readily undergoes disproportionation yielding 2, diazobarbituric acid (1), and alloxan (5). 2 can be prepared in good yield by coupling diazobarbituric acid with barbituric acid in alkaline medium.
    Notes: Azobarbitursäure (2) tritt als Nebenprodukt der Reaktion zwischen Barbitursäure und Carbamoylazid (H2NCON3) zu 5-Aminocarbonyl-barbitursäure auf. 2 wird durch Bromwasser zu Aloxanazin (3) oxydiert, das leicht disproportioniert, wobei 2, Diazobarbitursäure (1) und Alloxan (5) entstehen. 2 wird in guter Ausbeute durch Kupplung von Diazobarbitursäure mit Barbitursäure in alkalischem Medium dargestellt.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 139-145 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cyanacetaldehyde Derivatives and Reaction ProductsThe reaction of malondialdehydedioxim (2) with aromatic diazonium salts or nitrous acid leads to derivatives 5 of cyanoacetaldehyde in a quite simple way. The hydrazones of these compounds can be converted into 1-substituted 5-aminopyrazoles 6.
    Notes: Ausgehend vom Malondialdehyddioxim (2) erschließt sich über die Umsetzung mit Aryldiazoniumsalzen oder salpetriger Säure ein einfacher Zugang zu Cyanacetaldehyd-Derivaten 5, von denen sich die Hydrazone in 1-substituierte 5-Amino-pyrazole 6 überführen lassen.
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 124-138 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Triazolylbenzoic Acids and Acylaminoquinazolones from Benzoxazinones and Curbohydrazideso(4-s-Triazolyl)benzoic acids 2 can easily be prepared in good yields from so-called acylanthranils with carbohydrazides in boiling ethanol. In hot benzene, the isomeric 3-acyl-amino-4-quinazolones 1 are formed from the same components. Both reactions proceed via amidrazones 11, which are formed by the reaction of the terminal hydrazide nitrogen atom with the oxazinone nucleus at C-2. - 3,4,5-Trisubstituted s-triazoles can also be made from N-substituted imidoyl chlorides with hydrazides. - s-Triazolo[4,3-a]quinolines of the type 18c are available by intramolecular condensation of certain triazolylbenzoic acids.
    Notes: o-[s-Triazolyl-(4)]-benzoesäuren 2 können präparativ einfach aus [Acylanthranilen] und Carbonsäurehydraziden in siedendem absolutem äthanol gewonnen werden. Aus den gleichen Komponenten bilden sich in Benzol die isomeren 3-Acylamino-chinazolone-(4) 1. Beide Reaktionen verlaufen über Amidrazone 11, gebildet bei der Reaktion des endständigen Hydrazid-Stickstoffs mit dem Kohlenstoff-Atom 2 des Oxazinon-Ringes. - Eine weitere Synthese für den 3.4.5-trisubstituierten s-Triazol-Ring ist mit N-substituierten Imidchloriden 7 und Hydraziden ausführbar. Bestimmte Triazolylbenzosäuren lassen sich zu s-Triazolo[4.3-a]chinolinen vom Typ 18c kondensieren.
    Additional Material: 2 Tab.
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  • 7
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 198-204 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Frog Venoms.Isolation and Structure of Pumiliotoxin CPumiliotoxin C, a base of the composition C13H25N, is isolated as the crystalline hydrochloride from the skin extracts of Dendrobates pumilio, a strikingly colored Panamanian frog. Complete X-ray analysis of this new venom by the so-called symbolic addition procedure establishes the structure as 2-n-propyl-5-methyl-cis-decahydroquinoline, a type of base, though related to coniine, is here reported for the first time as a natural product. The relative configurations of the four asymmetric centers are elucidated. In addition to this venom there are the congeners pumiliotoxins A and B, as well as further homologs and analogs which have also been isolated from the related frog Dendrobates auratus, and characterized by mass spectra.
    Notes: Aus dem Hautextrakt des in Panama vorkommenden, auffallend gefärbten Froschs Dendrobates pumilio läβt sich das gut kristallisierende Hydrochlorid einer Base Pumiliotoxin C der Formel C13H25N isolieren. Durch Röntgen-Strukturanalyse dieser Base nach dem „symbolischen Additionsverfahren“ (symbolic addition procedure) läβt sich zeigen, daβ es sich um einen zum ersten Mal in der Natur beobachteten, dem Coniin weitläufig verwandten Giftstofftyp handelt, nämlich um ein 2-n-Propyl-5-methyl-cis-decahydrochinolin, dessen vier asymmetrische Zentren in ihrer relativen stereochemischen Bezeichnung aufgeklärt werden. Neben Pumiliotoxin C leiten sich auf Grund der Massenspektren die Pumiliotoxine A und B sowie noch weitere aus dem verwandten Frosch Dendrobates auratus isolierte Basen von einem ähnlichen cis-Deca- oder Octahydrochinolin-System ab.
    Additional Material: 5 Ill.
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  • 8
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Constituents of the Horse Chestnut, VII 1). O-Isopropylidene Derivatives of Protoescigenin, Barringtogenol C,and their 21-Angelic (Tiglic) Acid and 28-Angelic (Tiglic) Acid EstersThe O-isopropylidene derivatives of protoescigenin barringtogenol C, and their 21-angelic (tiglic) acid and 28-angelic(tiglic) acid esters have been prepared by reaction with acetone/p-toluenesulfonic acid. The substances were isolated by column chromatography and their structures have been determined.
    Notes: O-Isopropyliden-Derivate von Protoäscigenin, Barringtogenol C und von deren 21- bzw. 28-Angelika(Tiglin)säureestern werden durch Umsetzung mit Aceton/p-Toluolsulfonsäure hergestellt, durch Säulenchromatographie isoliert und in ihrer Struktur bestimmt.
    Additional Material: 3 Tab.
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  • 9
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 237-239 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses and Properties of Dithioamino Acid EstersFrom the previously unknown class of dithioamino acid esters three members have been synthesized: N-benzoyl dithioglycine ethyl ester, ∊-amino-dithiocaproic acid ethyl ester p-toluenesulfonate, and N-acetyl dithiophenylalanine ethyl ester. The syntheses have been carried out via the nitriles. The absorption bands of the C=S-group are at approximately 3100 Å and approximately 4500 Å (table 1). The proton magnetic resonance spectrum of the prototypic N-benzoyl dithioglycine ethyl ester (page 238) is consistent with its proposed structure.
    Notes: Aus der bisher unbekannten Gruppe der Dithioaminosäureester werden drei Vertreter dargestellt: N-Benzoyl-dithioglycinäthylester, ∊-Aminodithiocapronsäureäthylester-p-toluolsulfonat und N-Acetyl-dithiophenylalaninäthylester. Die Darstellung erfolgt über die Nitrile. Die Absorptionsbanden der C=S-Gruppe liegen bei ca. 3100 Å und ca. 4500 Å (Tab. 1). Das Protonenresonanzspektrum von N-Benzoyl-dithioglycinäthylester (S. 238) entspricht seiner Struktur.
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  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 725 (1969), S. 238-240 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 3H-DesmethylphalloinA radioactive desmethylphalloin (2) is obtained by reduction of the CO-group of ketophalloidin (1) with 3H-containing NaBH4. It has almost the same toxicity as phalloidin (LD50=2.2 mg/kg body weight of the white mouse). As a consequence of the relatively high radioactivity (220 μCi/mg) 2 gives during storing a degradation product, which can be separated by chromatography on Sephadex G-25 or LH-20 using water as eluent, and whose UV-spectrum indicates a sulfoxide structure.
    Notes: Durch Reduktion der Ketogruppe des Ketophalloidins (1) mit 3H-haltigen NaBH4 wird ein radioaktives Desmethylphalloin (2) erhalten, das etwa dieselbe Toxizität wie Phalloidin besitzt. Infolge der hohen spezif. Aktivität (220 μCi/mg) entsteht beim Lagern aus 2 ein chromatographisch an Sephadex G-25 oder LH-20 in Wasser abtrennbares Zersetzungsprodukt, dessen UV-Absorptionskurve auf das Vorliegen einer Sulfoxid-Struktur hindeutet.
    Additional Material: 1 Ill.
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  • 11
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 726 (1969), S. 13-18 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Phosphorus Pentafluoride and Boron Trifluoride in Liquid TrifluoromethanePhosphorus pentafluoride and boron trifluoride form conducting solutions in liquid trifluoromethane. The adducts (CH3)3N·PF5 and (CH3)3N·BF3 and also the salts [(CH3)3NH] [PF6] and [(CH3)3NH][BF4], respectively, may be obtained from these solutions by addition of trimethylamine. Complex anions containing trifluoromethyl ligands are not formed.
    Notes: Phosphor(V)-fluorid bzw. Bor(III)-fluorid zeigen in flüssigem Trifluormethan elektrisches Leitvermögen. Aus den Lösungen lassen sich mit Trimethylamin die Addukte (CH3)3N· PF5 bzw. (CH3)3N·BF3 und die Salze [(CH3)3NH][PF6] bzw. [(CH3)3NH][BF4] gewinnen. Trifluormethylhaltige Komplex-Anionen werden nicht gebildet.
    Additional Material: 3 Ill.
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  • 12
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 726 (1969), S. 36-41 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Carbenes Derived from Bicyclo[3.3.0]octaneBicyclo[3.3.o]octane derivatives with divalent carbon in position 2 show little tendency to undergo intramolecular insertion with formation of tricyclo[3.2.1.02,8]octane derivatives. The tosylhydrazone of 2-bicyclo[3.3.0]octanone (1) yields predominantly 2-bicyclo[3.3.0]octene (2). the tosylhydrazone 7 of 10 bicyclo[3.3.0]octene-4-one prefer intermolecular reactions 9formation of ether) and affords less than 10% fo 4-tricyclo[3.2.1.02,8] octene (8).
    Notes: Carbene der Bicyclo[33.30]octan-Reihe mit zweibindigem Kohlenstoff in 2-Stellung zeigen geringe Neigung zu intramolekularer Einschiebung unter Bildung von Tricyclo[3.2.1.02.8]-octan-Derivaten. Aus Bicyclo[3.3.0]octanon-(2)-tosylhydrazon (1) entsteht bei alkalisch thermischer Spaltung vorwiegend Bicyclo[3.3.0]octen-(2) (2). Bicyclo[3.3.0]octen-(1)-on(4) tosylhydrazon (7) weicht auf intermolekulare Reaktionen (äther-Bildung) aus und liefert maximal 10% Tricyclo[3.2.1.02.8]octen-(4) (8).
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  • 13
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 726 (1969), S. 77-80 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Preparation of AziridinesAddition of chlorine and acetonitrile to olefins yields dichloroimines 1. By methanolysis of 1, followed by acid hydrolysis, we obtained via the iminoesters 4 the β-chloroamines 5, which are easily converted into aziridines 3. It is not necessary to isolate the intermediate products.
    Notes: Eie Addition von Chlor und Acetonitril an Olefine ergibt Dichlorimine 1. Durch Methanolyse von 1 und anschließende saure Hydrolyse erhielten wir über die Iminoester 4 die β-Chloramine 5, die sich leicht in Aziridine 3 überführen lassen. Die Isolierung der Zwischenprodukte ist nicht erforderlich.
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  • 14
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 727 (1969), S. 106-109 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses with Quinones in situ, VII 1). Preparation of 7-Dimethylamino-2-hydroxyphenothiazin-3-one7-Dimethylamino-2-hydroxyphenothiazin-3-one (4) is obtained for the first time by using 2-amino-5-dimethylanilin-thiosulfuric acid (1) as starting material. There are two different procedures, the second procedure allows the isolation of the intermediate indophenol.
    Notes: 7-Dimethylamino-2-hydroxy-phenothiazinon-(3) (4) wird auf zwei Wegen aus 2-Amino-5-dimethyl-anilin-thioschwefelsäure (1) erstmalig dargestellt. Bei dem zweiten Reaktionsweg läßt sich die Indophenol-Zwischenstufe isolieren.
    Additional Material: 1 Ill.
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  • 15
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 727 (1969), S. 125-129 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A Novel Synthesis of AntamanidBy cyclization of the linear decapeptide phenylalanyl-phenylalanyl-prolyl -prolyl-phenyl-alanyl-phenylalanyl-valyl-prolyl-prolyl-alanine (position 5 → 4 in formula 1,) with the help of dicyclohexylcarbodiimide/N-hydroxy-succinimide (DCC/HOSu) antamanid (1,) is obtained in a 36.5% yield.
    Notes: Durch Ringschluß des linearen Decapeptids Phe-Phe-Pro-Pro-Phe-Phe-Val-Pro-Pro-Ala (Stellung 5 → 4 in Formel 1) mittels Dicyclohexylcarbodiimid/N-Hydroxy-succinimid wird das cyclische Decapeptid Antamanid in 36.5 proz. Ausbeute erhalten.
    Additional Material: 1 Ill.
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  • 16
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Catalytic Conversion of Olefins, I If'). Synthesis of cis,trans-l.5-Cyclodecadiene and I,trans-4.9-Decatriene. Co-oligomerization of Butadiene with EthyleneButadiene and ethylene can react together in the presence of “naked nickel” or nickel ligand catalytic systems to give cis,trans-1,5-cyclodecadiene (4; in yields of up to 80%). The intermediate 1 rearranges thermally to cis-1,2-divinylcyclohexane (6). 1, trans-4.9-Decatriene (5) is formed preferentially from butadiene and ethylene at 100°. Other unsaturated systems may also be included in the co-oligomerization reaction.
    Notes: Mit Hilfe von “nacktem Nickel” bzw. von Ligand/Ni-Katalysatoren können Butadien und äthylen zum cis.trans-Cyclodecadien-(1.5) (4) zusammengelagert werden (Ausbeute bis zu 80%). 4 lagert sich thermisch in cis-1.2-Divinyl-cyclohexan (6) um. Bei 100° entsteht aus Butadien und äthylen bevorzugt Decatrien-(1.trans-4.9) (5). In die Mischoligomerisation können auch andere ungesättigte Systeme einbezogen werden.
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  • 17
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Diazocarbonyl Compounds, XXXIII1). Reaction of o-Quinone Diazides with Ethyl p-Nitrophenylacetate and p-Nitrobenzylcyanideo-Quinone diazides react with p-NO2-C6H4-Ch2-CO2C2H5 and p-NO2-C6H4-CH2-CN to 2-hydroxyphenylhydrazones of the related keto compounds (table 1). The substances 1-9 are indicators. The cyano compound 8 shows solvatochromy reaching over the whole visible spectrum. The colour of the solution is related to the ability of the solvent to solvatise protons.
    Notes: o-Chinondiazide reagieren mit p-Nitrophenyl-essigsäureäthylester sowie mit p-Nitrobenzylcyanid zu 2-Hydroxy-arylhydrazonen der entsprechenden Keto-Verbindungen (Tab. 1). Die Substanzen 1-9 sind Indikatoren. Die Cyan-Verbindung 8 zeigt eine über das ganze sichtbare Spektrum gehende Solvatochromie, wobei ein Zusammenhang zwischen der Lösungsfarbe und der Fähigkeit des Lösungsmittels, Protonen zu solvatisieren, besteht.
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  • 18
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 727 (1969), S. 228-230 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Mesomeric Kations, I. Synthesis of S-Aryl-thiuronium SaltsS-Aryl-tetramethyl-thiuronium perchlorates (3) are synthesized by reaction of tetramethylthiourea with activated aromatic halogen compounds (2) or with substituted diazonium salts. The reaction of tetramethylchloroformamidinium chloride (4) with thiophenols also gives the compounds 3 in high yields.
    Notes: Zur Synthese von S-Aryl-tetramethylthiuroniumperchloraten (3) läßt sich Tetramethylthioharnstoff mit aktivierten Halogenbenzolen (2) oder mit Diazoniumsalzen arylieren. Außerdem führt die Umsetzung von Tetramethyl-chlorformamidiniumchlorid (4) mit Thiophenolen ebenfalls glatt zu den Verbindungen 3.
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  • 19
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 728 (1969), S. 12-16 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of Iodosobenzene dichloride with Symmetrical EthersIodosobenzene dichloride (1) reacts with symmetrical ethers 2 under exposure to light, yielding monochloroethers 3. The formation of 1,2-dichloroethers 9, which are formed by interaction of chlorine with ethers 2, is not observed. The reaction of 1 with 2 can be explained by means of a chain reaction of C6H5-I -Cl radicals.
    Notes: Phenyljodidchlorid (1) reagiert mit symmetrischen äthern 2 bei Lichteinwirkung zu Monochloräthern 3. Das Auftreten von 1.2-Dichloräthern 9, die bei der Einwirkung von Chlor auf äther 2 entstehen, wird nicht beobachtet. Mit einer Kettenreaktion über C6H5-J.-Cl-Radikale läßt sich die Umsetzung von 1 mit 2 zu Monochloräthern 3 erklären.
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  • 20
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 728 (1969), S. 36-43 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: I,2-Dithia-cyclopentenes, X V1). 3-Halogeno-I,2-dithiolium-compounds and Compounds with Positive Halogen3, 5, 9, 10 have been prepared from 3-halogeno-1,2-dithiolium-compounds and compounds with positive halogen. The 3-halogeno-5-amino-1,2-dithiolium-compound 13 does not react; that is interpreted by resonance structures of 13.
    Notes: 3-Halogen-1.2-dithiolium-Verbindungen mit Chlor oder dem Phenyl-Rest in 5-Stellung reagieren mit Substanzen, die „positives Halogen“ enthalten, unter Eliminierung von elementarem Halogen zu Verbindungen vom Typ 3, 5, 9, 10. Die 3-Halogen-5-amino-1.2-dithiolium-Verbindung 13 reagiert nicht; Mesomeriebetrachtungen erklären den Befund.
    Additional Material: 3 Tab.
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  • 21
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 728 (1969), S. 64-87 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on Cyclohexenes, I. Synthesis and Reactions of 3-Amino-4-phenyl-cyclohexenes-(l), a Novel Class of AnalgesicsEthyl atropate (1a) and related alkenes (1b-e) undergo diene-(1.4)-cycloaddition reactions with the electron-rich 1-amino-butadienes-(1,3) 2a-e to give the stable, stereoisomeric 3-amino-4-phenyl-cyclohexenes-(1) 3a-i and 4a-i. The ratio of the isomers does not depend on the dielectric constant of the solvent used in case of 3r-dimethylamino-4c-ethoxycarbonyl-4t-phenyl-cyclohexene-(1) (3a) and 3r-dimethylamino-4t-ethoxycarbonyl-4c-phenyl-cyclohexene-(1) (4a). It however depends on the spatial requirements of the substituents of the alkene and diene (table 1). Structure of 3a and 4a have been established by NMR, mass and infrared spectra analysis and by degradation. - Assigned conformational preferences to 3a-i and 4a-i are confirmed by the hydrogenation rate of the cyclohexene double bond, by supra-annular effects and by the basicity constants of the hydrogenated and nonhydrogenated compounds. - All cyclohexenes 3a-i and 4a, e, g, i are active analgesics. The cyclohexanes 7-10, 17, and 22-25 have no or only weak analgesic properties.
    Notes: Atropasäureäthylester (1a) und verwandte Alkene (1b-e) gehen mit den Elektronen-reichen 1-Amino-butadienen-(1.3) 2a-e Dien-(1.4)-Cycloadditionen ein, die zu stabilen, stereoisomeren 4-Phenyl-3-amino-cyclohexenen-(1) 3a-i und 4a-i führen. Das Verhältnis der Isomeren ist beim 3r-Dimethylamino-4t(bzw. 4c)-phenyl-4c(bzw. 4t)-äthoxycarbonyl-cyclohexen-(1) (3a bzw. 4a) unabhängig von der Dielektrizitätskonstanten des bei der Addition verwendeten Lösungsmittels, jedoch abhängig von der Raumerfüllung der Liganden am En und Dien (Tab. 1). Die Struktur von 3a und 4a wird durch Massen-, NMR und IR-spetroskopische Untersuchungen sowie durch Abbau bewiesen. Mittels Konformationsbetrachtungen gewonnene Aussagen über den räumlichen Bau von 3a-i und 4a-i werden bestätigt vom Geschwindigkeitsverlauf der Hydrierung der Ring-Doppelbindung, von supra-annularen Effekten und den Basizitätskonstanten der hydrierten bzw. nicht-hydrierten Verbindungen. - Alle Cyclohexene 3a-i und 4a,e,g,i besitzen analgetische Aktivität; die Cyclohexane 7-10, 17 und 22-25 besitzen keine oder nur schwache analgetische Eigenschaften.
    Additional Material: 11 Tab.
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  • 22
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 728 (1969), S. 115-143 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metal Complexes of PorphyrinsThe preparation of a series of porphyrin metal complexes is described, and the widely varying spectra of porphyrin complexes are interpreted in terms of known and newly discovered facts. The salts of ms-tetrasubstituted porphins have recently been recognized as derivatives of alloporphins (6); similarly, the porphyrins of the hemin and chlorophyll series form olivegreen or brown allo-complexes. The constitution 8 hitherto assigned to all porphin complexes actually only applies to the red-normal complexes including oxyhemoglobin. Valence-tautomeric chromophores such as 11, 15, and others are to be considered for allo-complexes including hemin.
    Notes: Die Darstellung einer Reihe von Porphyrin-Metall-Komplexen wird beschrieben. Unter Berücksichtigung von bekanntem und neuem Tatsachenmaterial wird eine Deutung der unterschiedlichen Elektronenspektren der Porphyrinkomplexe gegeben. Ausgehend von Salzen ms-tetrasubstituierter Porphine, die als Alloporphin-Derivate (6) erkannt wurden, werden olivgrüne bis braune Metallchelate von Porphyrinen der Hämin- und Chlorophyll-Reihe als Allokomplexe aufgefaßt. Die bisher den Porphyrin-Komplexen allgemein zuerteilte Konstitution 8 gilt nur für die roten Normalkomplexe, denen auch Oxyhämoglobin zuzurechnen ist. Für die Allokomplexe, zu denen Hämin gehört, werden Valenz-tautomere Chromophore wie 11, 15 und andere angenommen.
    Additional Material: 4 Ill.
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  • 23
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 728 (1969), S. 184-192 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: N-Substituted Derivatives of Dehydroubietylamine and DehydroabietylguanidineThe following derivatives of dehydroabietylamine have been synthesized in order to investigate their antimicrobial activity: N-monoalkyl- and N.N-dialkyl-dehydroabietylamines; dehydroabietylguanidines, which are substituted at the N- or N′-atom by an alkyl-, substituted alkyl-, acyl-, amino- or nitro-group; dehydroabietylurea, -thiourea, salts of dehydroabietylisourea and -isothiourea, quaternary dehydroabietylammonium salts and 2-dehydroabietylamino-pyrimidine.
    Notes: Zur Untersuchung ihrer antimikrobiellen Wirkung werden aus Dehydroabietylamin dargestellt: N-Monoalkyl- und N.N-Dialkyl-dehydroabietylamine, am N- oder N'-Atom durch eine Alkyl-, substit. Alkyl-, Acyl-, Amino- oder Nitro-Gruppe substituierte Dehydroabietylguanidine, Dehydroabietylharnstoff, -thioharnstoff, Salze des Dehydroabietylisoharnstoffs und -isothioharnstoffs, quaternäre Dehydroabietylammoniumsalze und 2-Dehydroabietyl-amino-pyrimidin.
    Additional Material: 2 Tab.
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  • 24
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 1-7 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Organometallic Compounds of the Groups IVa and Va, I. Alkoxytriphenylursine- and Alkoxytriphenylantimony HalidesThe reactions of tert.-butylhypohalities (2a and b) with triphenylarsine (1c) and triphenyl-antimony (1a) have been investigated an dht eproperties of the triphenyl-tert.-butoxyarsine-and - antimony halides (3a-d) formed have been examined.
    Notes: Die Umsetzung von tert.-Butylhypohalogeniten (2a und b) mit Triphenylarsin (1c) un d-stibin (1a) und die Eigenschaften der dabei entstehenden Triphenyl-tert.-butyloxy-arsen - und -antimonhalogenide (3a-d) werden untersucht.
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  • 25
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 8-20 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Wagner- Meerwein Rearrangements in the Bicyclo[3.2.2rsqb;nonane Series I )Deamination of the epimeric 6-aminobicyclo[3.2.2]non-8-enes (6 and 7) and 6-aminobicyclo-[3.2.2]nonanes (8, X = NH2 and 9) mainly proceeds via a stereospecific rearrangement to yield exo-alcohols of hte bicyclo[3.3.1]nonane or bicyclo[4.2.1]nonane series with high stereospecifity. In addition, tricyclo[4.2.1.02.8]nonan-7-ol (10) was produced from the endo-amin 7. - In the presence of silver bromide 2-bromobicyclo[3.2.2]nonane (8, X = Br) rearranges to 2-bromobicyclo[3.3.1]nonane (2, Y = Br). - Both the dehydration of bicyclo[3.2.2]nonan-6-ol (1, X = OH) with phosphoric acid and the acid-catalyzed rearrangement of bicyclo-[3.2.2]non-6-ene (12) give rise to bicyclo[3.3.1]non-2-2ne (11, X = H). The reaction of 12 with an excess of monoperphthalic acid yields syn- and anti-bicyclo[3.3.1.13.9]decane (17). -The deamination of 2e-aminomethylbicyclo[3.2.1]octane (18 gives a mixture of alcohols consisting of bicyclo-[4.2.,1]nonan-3-ol (36), bicyclo[4.2.1]nonan-2-ol (3, Y = OH), bicyclo[3.3.1]nonan-2-ol (2, Y = OH), and 2a-and 2e-methylbicyclo[3.2.1]octan-2e- and 2a-ols (20 and 19).
    Notes: Die Desaminierungen der epimeren 6-Amino-bicyclo[3.2.2]nonene-(8) (6 und 7) und 6-Aminobicyclo[3.2.2]nonane (8, X = NH2, und 9) führen stereospezifisch zu exo-Alkoholen der Bicyclo[3.3.1]nonan- oder Bicyclo[4.2.1]nonan-Reihe. Das endo-Amin 7 liefert daneben Tricyclo[4.2.1.02.8]nonanol-(7) (10). - 6-Brom-bicyclo[3.2.2]nonan (8, X = Br) lagert sich in Gegenwart von AgBr in 2-Brom-bicyclo[3.3.1]nonan (2, Y = Br) um. -Die Dehydratisierung von Bicyclo[3.2.2]nonanol-(6) (1, X = OH) mit Phosphorsäure und die säurekatalysierte Umlagerung von Bicyclo[3.2.2]nonanol-(6) (1, X = OH) mit Phosphorsäure und die säurekatalysierte Umlagerung von Bicyclo[3.2.2]nonen-(6) (12) führen zu Bicyclo[3.3.1]nonen-(2) (11, X = H). - Aus 12 bilden sich mit überschüss. Monoperphthalsäure syn- und anti- Bicyclo[3.3.1]nonen-(2)-ol-(9) (14 und 15) sowie vermutlich 10-Oxatricyclo[3.3.1.13.9]decan (17). - Bei der Desaminierung des 2e-Aminomethyl-bicyclo[3.2.1]octans (18) entstehen Bicyclo[4.2.1]nonanol-(3) (36), Bicyclo[4.2.1]nonanol-(2) (3), Y = OH), Bicyclo[3.3.1]nonanol-(2) (2, Y = OH) sowie 2a und 2e-Methyl-bicycol[3.2.1]octanol-2c und 2a) (20 und 19).
    Additional Material: 1 Tab.
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  • 26
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 52-63 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of Ally1 Alcohols with Active Methine and Methylene Compoundsγ.δ-Unsaturated ketones 4 are intermediates in several syntheses of natural products. They may be obtained from allyl alcohols and β-keto esters. Novel synthetic approaches to γ.δ-unsaturated ketones 4 and the related compounds 12, 14, 16, and 18 are described (tables 7-10). The investigations lead to a new synthetic route for the preparation of the juvenile hormone (10).
    Notes: γ.δ-Ungesättigte Ketone 4, herstellbar aus Allylalkoholen und β-Ketoestern, sind Zwischenprodukte verschiedener Naturstoff-Synthesen. Es werden neue Synthesemöglichkeiten von 4 und den damit verwandten Verbindungen 12, 14, 16 und 18 (Tabb. 7 - 10) beschrieben. Die Arbeiten führen zu einem Herstellungsverfahren des Juvenilhormons (10).
    Additional Material: 1 Ill.
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  • 27
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 69-72 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Cyclopentadienones, XVII).1,4-Cycloaddition of Dibenzoyldiimide to CyclopentadienonesThe cyclopentadienones 2-7 and dibenzoyldiimide (1) give the corresponding 1,4-compounds 8-12. By heating in xylene the product 8 rearranges to the lactone 13. Reaction mechanisms are discussed.
    Notes: Die Cyclopentadienone 2-7 werden mit Dibenzoyldiimid (1) zu den entsprechenden 1.4-Addukten 8-12 umgesetzt. Erhitzen von 8 in Xylol liefert das Lacton 13. Die Reaktionsmechanismen werden diskutiert.
    Additional Material: 1 Tab.
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  • 28
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 106-118 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese of Phosphinimine CompoundsA number of new phosphinimine compounds of s-triazines is obtained by the reaction of triamino-s-triazine (9) with triphenylphosphine and halogenes (table 1) or of trichloromelamine (17, table 2) or hexachloromelamine (26, table 3) with tertiary phosphines. The components react in the absence of dehydrohalogenating compounds. Only one reaction step is necessary for the formation of the products. All these methods give pure products in good yields.
    Notes: Eine Reihe neuer Phosphinimin-Derivate von s-Triazinen (Tab. 1) wird in einer Stufe mit groβer Reinheit und hohen Ausbeuten aus Triamino-s-triazinen (9), Triphenylphosphin und Halogenen in Abwesenheit von Halogenwasserstoff bindenden Verbindungen sowie aus Trichlormelamin (17, Tab. 2) oder Hexachlormelamin (26, Tab. 3) und tertiären Phosphinen erhalten.
    Additional Material: 3 Tab.
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  • 29
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 146-151 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Synthesis of 1,2-BenzisothiazolesA new method has been found for the preparation of 1,2-benzisothiazoles (1). The compounds are formed by reaction of dihalomethyl-2,6-dihalobenzenes with elementary sulfur and ammonia in a solvent.
    Notes: Es wurde eine neue Herstellungsweise für 1.2-Benzisothiazole (1) gefunden. Die Verbindungen entstehen durch Umsetzen von 2.6-Dihalogen-benzylidenhalogeniden mit elementarem Schwefel und Ammoniak in einem Lösungsmittel.
    Additional Material: 3 Tab.
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  • 30
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 184-192 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ubiquinones and Related Compounds, XV. Photochemical Reaction of Ubiquinone-7trans-Ubiquinone-7 (1) is converted to several compounds by irradiation of its ethanolic solution with sunlight. One of them, 2a, had been reported previously by us to be an isomer in which the β,γ-double bond of 1 has migrated to the α,β-position. 2a is reinvestigated and its correct structure found to be trans-γ-ethoxy-isoubiquinone-7 (chart 1). In methanol 1 gives the γ-methoxy compund 2b in the same manner. The configurations of α,β-double bond in isoubiquinone groups, 2a, 2b, 2c, and 8 were deduced from the n.m.r. spectra of the corresponding hydroquinone diacetates 3a, 3b, 3c, 9 (figure 1). The mechanism of the photochemical reaction is discussed (chart 2).
    Notes: trans-Ubichinon-7 (1) geht in äthanol durch Sonnenbestrahlung in mehrere Substanzen über. Eine davon, 2a, wurde früher von uns als Isomeres von 1 angesehen, in welchem die β-γ-Doppelbindung in die α.β-Position verschoben ist. Die Struktur von 2a lieβ sich jetzt als trans-γ-äthoxy-isoubichinon-7 richtigstellen (Schema 1). 1 ergibt in Methanol analog das Methoxy-Derivat 2b. Die Konfiguration der α.β-Doppelbindung in der Isoubichinon-Gruppe 2a-c und 8 kann durch die NMR-Spektren ihrer Diacetylhydrochinone 3a-c und 9 festgestellt werden (Abb. 1). Der Mechanismus dieser Photoreaktion wird diskutiert (Schema 2).
    Additional Material: 1 Ill.
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  • 31
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 249-250 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On Natural Tannins, XLIII). (-)-Chebulic Acid from AlgarobillaChebulic acid (1, R = H) is prepared by acid hydrolysis of Algarobilla extracts. It has been shown to be the optical antipode of the acid obtained from Myrobalanes.
    Notes: Aus Algarobilla-Extrakten wird durch Hydrolyse Chebulsäure (1, R = H) abgespalten, die sich als das Spiegelbild der aus Myrobalanen erhaltenen Säure erweist.
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  • 32
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 246-248 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enol Ethers, VIII. Reactions of Aldehydes with Electron-rich Alkenes1-Dimethylamino-1-ethoxyethylene (1) and 1,1-dipiperidinoethylene (2) react with aromatic aldehydes 3 to give cinnamamides. Coumarines are obtained on reaction with salicylic aldehydes.
    Notes: 1-Dimethylamino-1-äthoxy-äthylen (1) und 1.1-Dipiperidino-äthylen (2) reagieren mit aromatischen Aldehyden 3 zu Zimtsäureamiden. Mit Salicylaldehyden erhält man in glatter Reaktion Cumarine.
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  • 33
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions of CH-Active Compounds with Azides, XXVII ). Syntheses of a-Diazo-imines und Isomeric 1,2,3-Triazoles and Their Conversion into a-Diazo-immonium Salts1-Anilino-3-oxo-indenes 6a-f are converted into 1-oxo-3-arylimino-2-diazo-indanes 8a-c or 1-oxo-3-aryl-3H,8H-indeno [1,2-d]triazoles 9d-f by diazo group transfer with p-toluenesulfonyl azide in ethanol/potassium ethoxide. Both classes of substances add mineral acids to form 1-oxo-3-arylimmonium-2-diazo-indane-salts 10a-f. Treatment of the immonium salts with potassium hydroxide yields the α-diazo-imines 8a, b, e and f. 8c hydrolyses to give 1,3-dioxo-2-diazo-indane; 8d, which changes largely to 9d by cyclisation, is accessible by thermal ringopening of the latter. 1-Anilino-3-oxo-cyclohexenes-(1) 12a-f are transformed into 4-oxo-1-aryl-4,5,6,7-tetrahydro-benzotriazoles (14a-f) by diazo group transfer with high yields.
    Notes: 1-Anilino-3-oxo-indene 6a-f liefern bei der Diazogruppen-übertragung mit p-Toluolsulfonsäure-azid in äthanol/Kaliumäthylat 1-Oxo-3-arylimino-2-diazo-indane 8a-c bzw. 1-Oxo-3-aryl-3H.8H-indeno[1.2-d]triazole 9d-f. 8 und 9 addieren Mineralsäuren - 9 unter Ringöffnung - zu 1-Oxo-3-arylimmonium-2-diazo-indan-Salzen 10a-f. Mit Kaliumhydroxid erhält man daraus die α-Diazo-imine 8a, b, e und f. 8c hydrolysiert weiter zu 1.3-Dioxo-2-diazo-indan; 8d cyclisiert größtenteils zum Triazol 9d, ist aber durch dessen direkte thermische Isomerisierung zugänglich. 1-Anilino-3-oxo-cyclohexene-(1) 12a-f werden durch Diazogruppen-übertragung mit hohen Ausbeuten in 4-Oxo-1-aryl-4.5.6.7-tetrahydrobenzotriazole 14a-f umgewandelt.
    Additional Material: 8 Tab.
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  • 34
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Absolute Configuration of Optically Active, Naturally Occurring Dihydroisocoumarins, IIIs2).Determination of the Absolute Configuration of Agrimonolide and MelleineBy degradation with ozone and performic acid (S)-3-hydroxy-adipic acid is obtained from both agrimonolide (1) and (-)-β-tetralol (4), which is characterized as di-hydrazide 3. Therefore 1 and 4 have S-configuration at position 3 and 2 respectively. The positive CD at 260 mμ of 1 and phyllodulcine (7) is a proof of configurative identity. In contrast, melleine (8) shows at 257 mμ negative CD and therefore has R-configuration.
    Notes: Durch Abbau mit Ozon und Perameisensäure wird aus Agrimonolid (1) und (-)-β-Tetralol (4) die gleiche (S)-3-Hydroxy-adipinsäure erhalten und als Dihydrazid 3 charakterisiert. Damit geht für 1 und 4 die S-Konfiguration and C-3 bzw. C-2 hervor. Der positive CD von 1 und Phyllodulcin (7) bei 260 mμ beweist deren konfigurative übereinstimmung. Da der CD des Melleins (8) - wie 7 ein Salicylsäure-Derivat - bei 257 mü negativ ist, muß hier auf R-Konfiguration am C-3 geschlossen werden.
    Additional Material: 1 Ill.
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  • 35
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969) 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
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  • 36
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    Liebigs Annalen 729 (1969), S. 21-26 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Protonated Methylbenzene Tetrachloroaluminate ComplexesWell defined complexes from methyl substituted benzenes and aligated by proton magnetic resonance (figure 1, table 1). A few of these compounds can be characterized as σ-complexes. Under the conditions used σ-protonation requires a benzene ring with at least three methyl substituents and a 1,3,5-type of substitution. In all other cases complexes are formed, in which π-bonding is likely.
    Notes: Definierte Komplexe aus Methyl-substituierten Benzolen und Aluminiumchlorid/Chlorwasserstoff wurden erhalten und auf ihre NMR-Signale untersucht (Abb. 1, Tab. 1) Nur ein Teil dieser Verbindungen kann als σ-Komplex charakterisiert werden. Unter den angewandten Bedingungen ist für die σ-Protonierung Substitution mit wenigstens drei Methyl-Gruppen in 1.3.5-Stellung erforderlich. In allen anderen Fällen ist π-Komplex-Bildung wahrscheinlich.
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  • 37
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    Liebigs Annalen 729 (1969), S. 40-51 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Production and Reactions of N- MonoalkylamidosulfonylchloridesN-Monosubstituted amidosulfonylchlorides (1) may optimally be obtained by reaction between N-monosubstituted ammonium chlorides and sulfuryl chloride in acetonitrile. N-Monosubstituted amidosulfonylchlorides are very active intermediates, which react especially with reactive H containing compounds to give the free acids 2 (R = H), the esters or thioester 2,5, and 6, and the amides 7 and 8. The hydrogen of the amino group can also be substituted. In this way new compounds are accessible and other already known compounds can be produced more easily.
    Notes: Unter den Methoden zur Herstellung N-monosubstituierter Amidosulfonylchloride (1) erweist sich die Umsetzung von N-monosubstituierten Ammoniumchloriden mit Sulfurylchlorid in Acetonitril als am besten geeignet. N-Monosubstituierte Amidosulfonylchloride sind sehr reaktive Zwischenprodukte, die mit reaktionsfähigen, H-enthaltenden Verbindungen zu den freien Säuren 2 (R = H), den Estern bzw. Thioestern 2, 5 und 6 sowie den Amiden 7 und 8 reagieren können; außerdem besitzen sie einen leicht substituierbaren Wasserstoff an der Amino-Gruppe. Mit ihnen sind Verbindungen präparative leicht zugänglich, die bisher nicht oder nur umständlich gewonnen werden konnten.
    Additional Material: 8 Tab.
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  • 38
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 729 (1969), S. 73-82 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Catalytic Hydrogenation of PurinesHydrogenation of purines over platinum or palladium occurs initially, if at all, in the 1,6 positions (e. g. 1 → 4). The 1,6-dihydropurines, which can still be acetylated in the 7 or 9 position, can be hydrogenated further to hexahydro- and perhydropurines (20 and 13, respectively).
    Notes: Purine werden an Platin oder Palladium, wenn überhaupt, zuerst in 1.6-Stellung hydriert (z. B. 1 → 4); die 1.6-Dihydro-purine, die noch in 7- bzw. 9-Stellung acetylierbar sind, können dann weiter zu Hexahydro- bzw. Perhydro-purinen (20 bzw. 13) hydriert werden.
    Additional Material: 1 Tab.
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  • 39
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 722 (1969) 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 40
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 722 (1969), S. 29-37 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: a-Hydrazonocarboxylic Acid Azides, I. Aliphatic α-Hydrazonocarboxylic Acid AzidesThe title compounds 2, 5a-c, 6a-e are prepared by reaction of the analogous α-hydrazonocarboxylic acid hydrazides (1, 7a-c, 8a-e) with nitrous acid. Both classes form Z- and E-isomers. The α-hydrazonocarboxylic acid hydrazides (1, 8e), that are unsubstituted in the hydrazono group, prefer the Z-form, whereas those (7a-c, 8a- d), that are substituted in the hydrazono group, prefer the E-form. The Z-azides, prepared from the Z-hydrazides, are unstable and lose hydrazoic acid. The E-azides, prepared from the E-hydrazides, are stable, but change into the unstable Z-isomers on standing at room temperature when exposed to light. On boiling in toluene the E-isomers lose nitrogen to form substituted 1,2,4-triazol-5-ones (15a-c, 16a-d).
    Notes: Die Titelverbindungen 2, 5a-c, 6a-e entstehen aus den entsprechenden α-Hydrazonocarbonsäurehydraziden (1, 7a-c, 8a-e) durch Reaktion mit salpetriger Säure. Beide Substanzklassen treten in Z- und E-Form auf. Die in der Hydrazono-Gruppe unsubstituierten α-Hydrazonocarbonsäurehydrazide (1, 8e) liegen bevorzugt in der Z-Form, die entsprechend substituierten Hydrazide (7a-c, 8a-d) überwiegend in der E-Form vor. Die aus den Z-Hydraziden entstehenden Z-Azide sind instabil und spalten Stickstoffwasserstoffsäure ab. Die aus den E-Hydraziden entstehenden E-Azide sind stabil, wandeln sich jedoch bei längerem Stehenlassen und gleichzeitiger Lichteinwirkung in die instabilen Z-Azide um. Beim Kochen der E-Azide in Toluol wird Stickstoff abgespalten und es bilden sich substituierte 1.2.4-Triazolone-(5) (15a-c, 16a- d).
    Additional Material: 3 Tab.
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  • 41
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Intramolecular Rearrangements of Bicyclo[2,2, heptanes, XI1). Rearrangement of 1- Methyl-7,2-norbornanecarbolactone in Sulfuric AcidIn the presence of concentrated sulfuric acid 1-methyl-7,2-norbornanecarbolactone (1) rearranges to 3exo-methyl- and 1-methyl-2,6-norbornanecarbolactones (2 and 5). The structure of the hitherto unknown lactone 5 is established.
    Notes: 1-Methyl-norbornan-carbolacton-(7.2) (1) lagert sich unter dem Einfluß konzentrierter Schwefelsäure in 3 exo-Methyl- und 1-Methyl-norbornan-carbolacton-(2.6) (2 und 5) um. Die Struktur des bislang unbekannten Lactons 5 wird bewiesen.
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  • 42
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 722 (1969), S. 232-233 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloaddition of Dichloroketene to 2-ButyneDichloroketene generated in situ, gives with 2-butyne the 1,2-cycloaddition product 2,3-dimethyl-4,4-dichlorocyclo-2-buten-1-on (1).
    Notes: In situ erzeugtes Dichlorketen addiert sich an Butin-(2) zum 2.3-Dimethyl-4.4-dichlor-cyclobuten-(2)-on-(1) (1).
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  • 43
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Studies on the Occurence of Hydrogen Transfer, 191). Specific Reductive Cleavage of Some Acyl Groups from Nitrogen at the Mercury CathodeElectron donators in the aromatic acyl group and in the amine component shift the reduction potentials of sulfonamides and of carbonamides to more negative values, and hinder the cathodic cleavage. Electron acceptors have the opposite effect. Aromatic ligands on the nitrogen atom change the reduction potentials to more positive values. The influence of the substituents on the reduction potentials follows the Hammett relationship. - If a potential difference of at least 0.2 V exists between acyl groups (which may be in the same molecule, or in different molecules), then selective cleavage of the acyl group having the more positive potentials is possible.
    Notes: In Sulfon und Carbonamiden mit aromatischem Acyl-Rest werden die Reduktionspotentiale durch Elektronen-Donatoren im Acyl-Rest und in der Amin-Komponente zu negativeren Werten verschoben; dabei wird die kathodische Spaltung erschwert. Elektronen-Acceptoren wirken umgekehrt. Aromatische Liganden am Stickstoff verlagern das Reduktionspotential zu positiveren Werten. Die Abhängigkeit der Reduktionspotentiale vom Substituenten gehorcht der Hammett-Beziehung. - Besteht zwischen den Acylamino-Gruppen, die im gleichen Molekül oder auch in verschiedenen Molekülen gebunden sein können, ein Potentialunterschied von wenigstens 0.2 V, so ist eine selektive Abspaltung der Acyl-Gruppe mit dem positiveren Potential möglich.
    Additional Material: 1 Ill.
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  • 44
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 723 (1969), S. 41-46 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Tertiary and Quaternary Salts of Hexahydro-pyrimidinesThe mono- and bis-tertiary salts 7, 11, 12 may be obtained by reaction of 1.3-dialkylhexahydro-pyrimidines and hydrogen chloride in suitable solvents. - The mono-quaternary salts 8-10 are formed from 1.3-dialkyl-hexahydro-pyrimidines and alkyl halides in ether. The bis-quaternary salts 5, 6 and 13-17 result by alkylation of 1.3-dialkyl-hexahydro-pyrimidines with methyl bromide, methyl iodide or trialkyloxonium fluoroborates in polar aprotic solvents or by reaction of α-halogen amines with γ-chloropropyl amines.
    Notes: Aus 1.3-Dialkyl-hexahydro-pyrimidinen und Chlorwasserstoff sind in geeigneten Lösungsmitteln die mono-sowie bis-tertiären Salze 7, 11, 12 zu gewinnen. - Die monoquartären Salze 8-10 entstehen aus 1.3-Dialkyl-hexahydro-pyrimidinen und Alkylhalogeniden in Äther. Die bis-quartären Salze 5, 6 und 13-17 sind durch Alkylierung von 1.3-Dialkyl-hexahydropyrimidinen mit Methylbromid oder -jodid sowie Trialkyl-oxoniumfluoroboraten in polaren, aprotischen Lösungsmitteln oder durch Umsetzung α-halogenierter Amine mit γ-Chlorpropylaminen zugänglich.
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  • 45
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 723 (1969), S. 201-204 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Concerning the Mechanism of Catalytic Proton-Transfer by Diazomethane, IIMethyl 3-hydroxy-2-naphthoate (8) gives with 1 mole phenyl isocyanate in the presence of 1 mole deuterodiazomethane (1.6 g-atom D/mole) an adduct 9-d0 free from deuterium; the same reaction carried out with deuterated 8 and non-deuterated diazomethane gives 9-d1. These results are in accordance with a proton-transfer by proton-bridge complexes, whereas they exclude the proton-transfer by methyldiazonium cations.
    Notes: 3-Hydroxy-naphthoesäure-(2)-methylester (8) bildet mit 1 Mol. Phenylisocyanat in Gegenwart von 1 Mol. Deuterodiazomethan (1.6 g-Atom D/Mol) das D-freie Addukt 9-d0; bei der Reaktion mit deuteriertem 8 und undeuteriertem Diazomethan entsteht dagegen 9-d1. Die Befunde lassen sich durch Protonen-Übertragung über Protonbrückenkomplexe erklären und schließen die Protonen-Übertragung durch Methyldiazonium-Kationen aus.
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  • 46
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 724 (1969), S. 24-29 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Conjugation in Macrocyclic Bond Systems, XIII1). Further Compounds of the Hexa-m-phenylene TypeThe preparation of the sterically overcrowded hexamethyl hexa-m-phenylene 2 is reported. Spectroscopic properties (u. v., 1H-n.m.r.) and mass spectra of 2 are discussed with regard to the strong deviation from coplanarity present in this system. Synthesis and properties of 8,2′;8′,2″;8″,2-tris(dibenzothiophenylene) (10), a coplanar a coplanar derivative of 1, are reported.
    Notes: Das sterisch stark behinderte Hexamethyl-hexa-m-phenylen 2 wird hergestellt. Die spektroskopischen Eigenschaften (UV, 1H-NMR) und das Massenspektrum von 2 werden unter dem Gesichtspunkt der hier vorliegenden starken Abweichung von der Komplanarität diskutiert. Über Synthese und Eigenschaften des 8.2′;8′.2″;8″.2-Tris-dibenzothiophenylens (10), eines ebenen Derivats von 1, wird berichtet.
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  • 47
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 724 (1969), S. 66-70 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Photochemical and Thermal 1,4-Cycloaddition of Enamides to 1,2- Dicarbonyl CompoundsThe enamides 2 and 6 can be added to benzil and o-chinones photochemically and thermally to give the 1,4-dioxen derivatives 3 and 7. The thermal addition follows a two-step mechanism, as is shown by the formation of the same 1,4-dioxen compound 7b from the addition of cis- and trans-enamide to 5.
    Notes: Die Enamide 2 und 6 addieren sich photochemisch wie thermisch an Benzil und o-Chinone zu den 1.4-Dioxen-Derivaten 3 und 7. Der Verlauf der thermischen Addition ist zweistufig, wie bei der Reaktion von cis- und trans-Enamid (6b bzw. 2b) mit 5 gezeigt wird, die zu demselben 1.4-Dioxen-Derivat 7b führt.
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  • 48
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Nitromethane Condensation with Dialdehydes, XVI1) S-Benzyl Substituted Nitrodithiols by cyclizing Bismercaptoalkylation of Nitromethane2-Nitrocyclohexanedithiols with trans-, chiro-, and cis-configuration (5-7) are formed by nitromethane-cyclization of glutaraldehyde in the presence of α-toluenethiol or by reaction of 2-nitrocyclohexane-1,3-diol (11) with α-toluenethiol, the product distribution being dependent on the reaction conditions. - Analogously, a 1,4-dinitrocyclohexanetetrathiol (15) is formed from 1,4-dinitro-1,4-dideoxy-neo-inositol (13), whereas its tetraacetate 16 gives 2-nitro-5-benzylmercaptophenol (17), as a result of aromatization followed by nucleophilic displacement of one nitro group by a mercapto moiety. - Configuration and conformation of the nitro dithiols and of the sulfones 8-10 obtained on oxidation are deduced from n.m.r. spectra.
    Notes: Nitromethan-Cyclisierung von Glutardialdehyd in Gegenwart von Benzylmercaptan oder Umsetzung von 2-Nitro-cyclohexandiol-(1.3) (11) mit Benzylmercaptan führt zu 2-Nitro-cyclohexan-dithiolen mit trans-, chiro- und cis-Konfiguration (5-7), deren Mengenverhältnis von den Reaktionsbedingungen abhängt. - Aus 1.4-Dinitro-1.4-Dinitro-1.4-didesoxy-neo-inosit (13) erhält man analog ein 1.4-Dinitro-cyclohexantetrathiol (15), aus dem Dinitrotetraacetat 16 dagegen, infolge Aromatisierung und nucleophiler Verdrängung einer Nitro- durch eine Mercapto-Gruppe, 2-Nitro-5-benzylmercapto-phenol (17). - Konfiguration und Konformation der Nitrodithiole sowie der durch Oxydation erhaltenen Sulfone 8-10 ergeben sich aus den NMR-Spektren.
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  • 49
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 724 (1969), S. 128-136 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation und Hydrolysis of 4- Halogenomethylen-1.3-dioxolanes4-Halogenomethylen-1,3-dioxolanes (4a-o) are obtained by base-catalyzed addition of formaldehyde to 1-halogen-1-propyn-3-ols (3). Acid hydrolysis of the dioxolane derivatives 4 yields 1-halopropan-3-ol-2-ones (5a-f, i-o), which split off hydrogen halide to give 2,3-diketones 6 and 7a-c, if the hydroxyl group is attached to a primary or secondary carbon atom.
    Notes: Durch basenkatalysierte Addition von Formaldehyd an 1-Halogen-propin-(1)-ole-(3) (3) werden 4-Halogenmethylen-1.3-dioxolane (4a-o) erhalten. Die saure Hydrolyse von 4 führt zu 1-Halogen-propanol-(3)-onen-(2) (5a-f, i-o). Soweit diese eine primäre oder sekundäre Hydroxy-Gruppe enthalten (5a-f), werden sie beim Erwärmen in die 2.3-Diketone 6 bzw. 7a-c und Halogenwasserstoff gespalten.
    Additional Material: 2 Tab.
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  • 50
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    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 724 (1969), S. 155-158 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: 1-(2- Hydroxyphenyl)-3,5-diphenyl-Δ2-pyrazolines2-Hydroxyphenylhydrazine hydrochlorides 1a-g and chalcone form 1-(2-hydroxyphenyl)-3,5-diphenyl-Δ2-pyrazolines (2a-g). The isolation of chalcone 2-hydroxyphenylhydrazones 3a and 3b depends on the substituents of the compounds 1a-g. - 1,3,5-Triphenyl-Δ2-pyrazolines show fluorescence, 1-(2-hydroxyphenyl)-3,5-diphenyl-Δ2-pyrazolines do not. Acetylation of the phenyl group leads to fluorescent compounds 4a-e.
    Notes: Aus den 2-Hydroxy-phenylhydrazin-hydrochloriden 1a-g, und Benzylidenacetophenon werden 1-[2-Hydroxy-phenyl]-3.5-diphenyl-Δ2-pyrazoline (2a-g) hergestellt. In Abhängigkeit von der Substitution der Verbindungen 1a-g, können bei gleichen Reaktionsbedingungen die Benzylidenacetophenon-2-hydroxy-phenylhydrazone 3a und 3b als Zwischenstufen isoliert werden. - Im Gegensatz zu 1.3.5-Triphenyl-Δ2-pyrazolinen fluoreszieren 1-[2-Hydroxyphenyl]-3.5-diphenyl-Δ2-pyrazoline nicht. Acetylierung der Hydroxyl-Gruppe führt zu fluoreszierenden Verbindungen 4a-e.
    Additional Material: 2 Tab.
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  • 51
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 724 (1969), S. 183-193 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Triterpenes, XXVII1). The Structure of Musennin and DeglucomusenninThe bark of the roots of Albizzia anthelmintica (Brongn.) contains a mixture of saponins, the main components of which, musennin and deglucomusennin, have now been isolated. The sugar chains are attached to the 3-hydroxy group of the aglycon echinocystic acid. Deglucomusennin contains three molecules of l-arabino-pyranose in an unbranched chain. They are connected in α-1,2-position. Musennin has an additional molecule of D-glucose, in β-1,3-linkage to the last molecule of l-arabinose of the chain.
    Notes: Als Hauptkomponenten des Saponingemisches der Wurzelrinde von Albizzia anthelmintica (Brongn.) werden Musennin und Desglucomusennin erkannt, in denen jeweils eine Zuckerkette an die 3-Hydroxyl-Gruppe des Aglykons Echinocystsäure gebunden ist. Desglucomusennin enthält 3 Moll. l-Arabinose in Pyranoseform, die in unverzweigter α-1.2-Verknüpfung vorliegen. Musennin besitzt zusätzlich 1 Mol. D-Glucose, die in β-1.3-Form mit der endständigen Arabinose verbunden ist.
    Additional Material: 3 Tab.
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  • 52
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 725 (1969), S. 196-202 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: NMR-Spectroscopic Studies of Acyl GlycosesA NMR spectroscopical study of the p-cumaroyl-D-glucoses (1a-e), p-hydroxybenzoyl-D-glucose (2a-e), as well as of the p-cumaroyl-L-rhamnoses (3 and 4) and 5-p-cumaroyl-D-xylofuranose (5) was carried out (table 1). The configuration and conformation, and in the case of the 1-, 2-and 6-acyl-glucoses as well as of 4-p-cumaroyl-α-methyl-L-rhamnopyranoside (4) also the position of the acyl group, have been established. With the aid of synthetic sugar esters the structure of neobignonoside, neopetunoside, and negretein could be determined.
    Notes: Aus den NMR-Spektren von p-Cumaroyl- (1a-e), p-Hydroxy-benzoyl-D-glucosen (2a-e) sowie p-Cumaroyl-L-rhamnosen (3 und 4) und 5-p-Cumaroyl-D-xylofuranose (5) (Tab. 1) werden die Konformation, Konfiguration und im Falle der 1-, 2- und 6-Acylglucosen- sowie des 4-p-Cumaroyl-α-methyl-L-rhamnopyranosids (4) die Stellung des jeweiligen Acyl-Restes ermittelt. Mit Hilfe der synthetischen Zuckerester konnte die Struktur von Neobignonosid, Neopetunosid und Negretein geklärt werden.
    Additional Material: 1 Tab.
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  • 53
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 722 (1969), S. 80-97 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Oxidation Products of Thioamides, XX1). Thiourea S-dioxidesThe thiourea S-dioxides 8, 15, and 16 are prepared by oxidation of N-mono- and N.N′-disubstituted thioureas with hydrogen peroxide. Treatment of N.N′-disubstituted thiourea S-dioxides with acids affords formamidines. When N.N′-dineopentylthiourea is oxidized only N.N′-dineopentylformamidine (19) can be isolated. The properties and reactions of the thiourea S-dioxides are compared with those of pyridinesulfinic acids.
    Notes: Bei der Oxydation N-mono- und N.N′-disubstituierter Thioharnstoffe mit H2O2 lassen sich die Thioharnstoff-S-dioxide 8, 15 und 16 isolieren. Durch Behandlung mit Säuren entstehen aus N.N′-disubstituierten Thioharnstoff-S-dioxiden Amidine; bei der Oxydation des N.N′-Di-neopentyl-thioharnstoffs wird einzig N.N′-Di-neopentyl-formamidin (19) erhalten. Eigenschaften und Reaktionen der Thioharnstoff-S-dioxide werden mit denen der Pyridinsulfinsäuren verglichen.
    Additional Material: 1 Ill.
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  • 54
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    Weinheim : Wiley-Blackwell
    Liebigs Annalen 722 (1969), S. 132-141 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Cycloaddition Reactions with α,β-Diheterosubstituted Olefins, I. Reactions with Sulfonyl IsocyanatesThe reaction of sulfonyl isocyanates with α,β-dialkoxy substituted olefins yields N-sulfonyl-3,4-dialkoxy-2-azetidinon compounds 3 as main products and N-sulfonylcarboxylamide compounds 4. Kinetic studies on the formation of β-lactams 3 are reported and the reactions of these compounds with methanol are described. The formation of β-lactams from α,β-sulfur and nitrogen substituted olefins can be detected by i.r.spectroscopy.
    Notes: Sulfonylisocyanate reagieren mit α.β-disauerstoffsubstituierten Olefinen unter 1.2-Addition zu 1-Sulfonyl-3.4-dialkoxy-azetidinon-(2)-Verbindungen 3. Daneben bilden sich durch Substitution α.β-ungesättigte N-Sulfonyl-carbonsäureamid-Verbindungen 4. Mit Schwefel-und Stickstoff-substituierten Olefinen wird eine Azetidinon-Bildung IR-spektroskopisch nachgewiesen. Reaktionsweisen sowie kinetische Untersuchungen zur Bildung der β-Lactam-Derivate 3 werden beschrieben.
    Additional Material: 7 Tab.
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  • 55
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Organophosphorus Compounds, XXIII1). A New Synthesis of Tetrazoles and Iminonitriles from N- Substituted IminophosphoranesA generally applicable synthesis of 1-R1-5-R2-substituted tetrazoles by reaction of the corresponding triphenyliminophosphoranes (C6H5)P=NR1 with acid chlorides R2COCl and NaN3 is reported. The same phosphoranes react with acyl cyanides R2COCN to form the iminonitriles R2C(CN)=NR1.
    Notes: Es wird über eine allgemein anwendbare Synthese von 1-R1-5-R2-substituierten Tetrazolen durch Umsetzung von Triphenyliminophosphoranen (C6H5)3P=NR1 (R1=Alkyl, Aryl) mit Säurechloriden R2COCl (R2=Alkyl, Alkenyl) und NaN3 berichtet. Triphenyliminophosphorane lassen sich mit Säurecyaniden R2COCN zu Iminonitrilen R2C(CN)=NR1 umsetzen.
    Additional Material: 1 Tab.
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  • 56
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    Liebigs Annalen 725 (1969), S. 73-86 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Ketene Derivatives, XVI1). Electrophilic Substitution of Simple Ketene S,N-AcetalsSimple ketene S,N-acetals [R-CH=C(SCH3)NR′ 2; R=Horalkyl] react with electrophiles such as acid chlorides, activated vinyl chlorides, ketene mercaptals, ethoxymethylene sulfonic acid amides, dinitrofluorobenzene, trichloro-s-triazine and o-nitrobenzenesulfenyl chloride to give β-substituted ketene S,N-acetals. In some cases products of secondary reactions are isolated; acid chlorides, for instance, sometimes give substituted β-acyloxyacrylic acid thioamides.
    Notes: Einfache Keten-S.N-acetale [R-CH=C(SCH3)NR′2; R=H oder Alkyl] reagieren mit Elektrophilen - z. B. mit Säurechloriden (zu 4), aktivierten Vinylchloriden (zu 12), Ketenmercaptalen (zu 14), Äthoxymethylensulfonamiden (zu 22, 23), Dinitrofluorbenzol (zu 19), Cyanurchlorid (zu 18) und o-Nitro-benzolsulfensäurechlorid (zu 20, 21) - zu β-substituierten Keten-S.N-acetalen. In einigen Fällen isoliert man Produkte von Folgereaktionen; mit Säurechloriden erhält man z. T. substituierte β-Acyloxy-acrylsäurethioamide (z. B. 8).
    Additional Material: 13 Tab.
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  • 57
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Fragmentation Reactions of Carbonyl Compounds with Electronegative β-Substituents, XV1). On the Reaction of Electronegatively β-Substituted Pivalic Acid EstersReaction of triiodo- (2) and tritosyloxy pivalic acid ester 3a, with sodium ethanolate affords 3-ethoxy-2-ethoxymethyl-1-propene (5) and diethyl carbonate (6) by a fragmentation reaction; on the other hand yields the tribromo pivalic acid ester 1b by neopentyl substitution 7a and b. Substitution of the monosubstituted pivalic acid esters 4a-d leads to the formation of 9, by products being formed at the same time. - Reaction of ethyl tosyloxypivalate (4b) with lithium organic compounds gives tetrasubstituted oxetanes 14.
    Notes: Trijod- (2) und Tritosyloxy-pivalinsäureester 3a liefern mit Na-äthylat 3-Äthoxy-2-äthoxymethyl-propen-(1) (5) und Kohlensäurediäthylester (6). Der Tribrom-pivalinsäureester 1b ergibt durch Neopentyl-Substitution 7a und b. Die monosubstituierten Pivalinsäureester 4a-d werden zu Methoxy-pivalinsäure-methylester (9) substituiert, wobei Nebenprodukte entstehen. - Umsetzung von Tosyloxy-privalinsäure-äthylester (4b) mit Lithiumorganylen ergibt die tetrasubstituierten Oxetane 14.
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  • 58
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    Liebigs Annalen 725 (1969), S. 154-166 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of Analogs of Dehydroabietylamine and Dehydroabietylguanidine by Total SynthesisAnalogs of racemic dehydroabietylamine and homodehydroabietylamine have been synthesized. The isopropyl group is replaced by hydrogen, or by a methyl or methoxy group. The guanidinium salts are prepared from the corresponding amines. Further variations include the additional introduction of a hydroxy group and substitution of the amino or guanidinium group by a quaternary ammonium or isothiouronium group.
    Notes: Es werden Analoge 2 des racemischen Dehydroabietylamins und Homodehydroabietylamins dargestellt. Dabei wird die Isopropyl-Gruppe durch Wasserstoff, eine Methyl- oder eine Methoxy-Gruppe ersetzt. Aus den Aminen werden die entsprechenden Guanidinium-Salze dargestellt. Weitere Variationen erstrecken sich auf die zusätzliche Einführung einer Hydroxy-Gruppe und Ersatz der Amino- bzw. Guanidinium-Gruppe durch eine quartäre Ammonium-oder Isothiuronium-Gruppe.
    Additional Material: 7 Tab.
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  • 59
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reactions with Diazocarbonyl Compounds, XXXII1). Synthesis of 2-Carboxy-5-hydroxytryptamine and Pyridazine Derivatives. Japp-Klingemann-Synthesis with p-Hydroxy-phenyl-diazonium Salts or p-Chinon-diazides, respectivelyp-Hydroxybenzenediazoniumchloride (1) and 2,6-dichloro-1,4-benzoquinone-4-diazide (2) react with 3-ethoxycarbonyl-2-piperidone (3) and with ethyl 2-acetyl-4-cyanobutyrate (10) (Japp-Klingemann synthesis) to give 4-hydroxyphenylhydrazones 6, 7 nad 11, 12 respectively. The hydrazones 6 and 7 are converted into the 5-hydroxyindole dervatives 8 and 9 (E. Fischer indole synthesis), while the hydrazone 12 is cyclized to the tetrahydropyridazine derivatives 13 and 14.
    Notes: p-Hydroxy-benzoldiaziniumchlorid (1) und 2.6-Dichlor-benzochinon-(1.4)-diazid-(4) (2) werden mit 3-Äthoxycarbonyl-piperidon-(2) (3) und mit 2-Acetyl-4-cyan-buttersäureäthylester (10) nach Japp und Klingemann zu den 4-Hydroxy-phenylhydrazonen 6 und 7 bzw. 11 und 12 umgesetzt. Die Hydrazone 6 und 7 lassen sich nach E. Fischer in die 5-Hydroxy-indol-Derivate 8 und 9 überführen, während das Hydrazon 12 zu den Tetrahydropyridazin Derivaten 13 und 14 cyclisiert.
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  • 60
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    Liebigs Annalen 726 (1969), S. 125-135 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Triterpenes XXVIII1). The Saponins of Spinach (Spinacia oleracea L.)Two saponins, spinasaponin A and B, have been isolated from the roots of spinach. The structures are elucidated by acid and enzymatic hydrolysis and by methylation, fission of the resulting methyl derivatives, and identification of the methyl sugars. Accordingly, spinasaponin A is 3O-[β-D-Glucopyranosyl(1 → 3)-β-D-glucuronopyranosyl]-3β-hydroxy-Δ12-oleanen-28-acid (1a), whereas B is the corresponding derivative 2a of hederagenin.
    Notes: Aus den Wurzeln des Spinats werden zwei Saponine, Spinasaponin A und B, isoliert, deren Struktur durch saure und enzymatische Hydrolyse sowie durch Methylierung, Spaltung der Methyl-Derivate und Identifizierung der methylierten Zucker ermittelt wird. Spinasaponin A ist demnach eine 3O-[β-D-Glucopyranosyl(1 → 3)-β-D-glucuronopyranosyl-(1)]-3β-hydroxy-Δ12-oleanen-28-säure (1a), während B das entsprechende Hederagenin-Derivat 2a ist.
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  • 61
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Preparation of 6α-Fluoro-11β, 21 -dihydroxy-l6α-methyl-l,4-pregnadiene-3,20-dione (Fluocortolone) via Substrate-Structure- Directed Specific 11β- Hydroxylation by Curvularia lunataThe formation of the by-products 14 and 13, with 9α- and 14α-hydroxy groups, in the 11β-hydroxylation of 6α-fluoro-21-hydroxy-16α-methyl-4-pregnene-3,20-dione (9b) with Curvularia lunata is inhibited by using a similar substrate with 5α-bromo-substituent by sterical shielding of the α-side. A subsequent route for the synthesis of 6α-fluoro-11β,21-dihydroxy-16α-methyl-1,4-pregnadiene-3,20-dione (15) is described.
    Notes: Die bei der 11β-Hydroxylierung von 6α-Fluor-21-hydroxy-16α-methyl-4-pregnen-3.20-dion (9b) mit Curvularia lunata entstehenden Nebenprodukte 14 und 13 mit 9α- und 14α-Hydroxy-Funktion treten bei Einsatz der 5α-Brom-substituierten Vorstufe 5 durch sterische Abschirmung der α-Seite nicht auf. Der weitere Synthesegang zu 6α-Fluor-11β.21-dihydroxy-16α-methyl-1.4-pregnadien-3.20-dion (15, Fluocortolon) wird beschrieben.
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  • 62
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    Liebigs Annalen 726 (1969), S. 216-218 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Syntheses and Properties of the Nine Isomeric Tolyl ToluatesThe title compounds 5-7 (a-c) are prepared and analyzed for their chemical and spectroscopical properties.
    Notes: Die Titelverbindungen 5-7 (a-c) werden hergestellt und ihre chemischen und spektroskopischen Eigenschaften untersucht.
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  • 63
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    Liebigs Annalen 727 (1969), S. 22-34 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of Thioamides with Sulfenyl ChloridesSulfenyl chlorides react with secondary thioamides to give iminomethyl disulfides 2. The sulfur atom is attacked by the sulfenyl chloride, even when the thioamide system is substituted by electron-withdrawing groups. Asymmetric iminomethyl disulfides obtained from the reaction of primary thioamides and sulfenyl chlorides decompose very easily, and in general they have been isolated as salts. In only one case has a neutral iminomethyl disulfide (23) been isolated. Thiobenzamide condenses with chlorocarbonyl sulfur chloride (21) to give 5-phenyl-1,2,4-dithiazol-3-one (28), whereas condensation with phenylimino-chloromethane sulfenyl chloride (20) leads to the corresponding dithiazole derivative 25, but only in small amounts.
    Notes: Durch Umsetzung von sekundären Thioamiden mit Sulfenylchloriden entstehen Iminomethyldisulfide 2. Der elektrophile Angriff des Sulfenylchlorids erfolgt auch dann am Thion-Schwefel, wenn das Thioamid-System elektronenziehende Substituenten trägt. Asymmetrische Iminomethyldisulfide aus primären Thioamiden und Sulfenylchloriden sind besonders leicht zersetzlich und nur als Salze isoliert worden. Nur in einem speziellen Fall wird ein neutrales Iminomethyldisulfid (23) aus einem primären Thioamid erhalten. Thiobenzamid reagiert mit Chlorcabonylschwefelchlorid (21) unter Ringschluß zu 5-Phenyl-1.2.4-dithiazolon-(3) (28). Bei Umsetzung mit Phenylimino-chlormethansulfenylchlorid (20) weicht die Reaktion aus, und das entsprechende Dithiazol-Derivat 25 wird nur in geringem Maße gebildet.
    Additional Material: 4 Tab.
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  • 64
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    Liebigs Annalen 727 (1969), S. 61-70 
    ISSN: 0075-4617
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: On the Structure of Thioamides and their Derivatives, Vl 1). Magnetic Anisotropy of the Thio-amide GroupModels of the magnetic anisotropy of the thioformamide and the thioacetamide system are developed with the aid of sterically fixed 1-thioacyl piperidines. In this way the different assignment of the signals of the cis- and trans-N-methyl groups in dimethylthioacetamide and dimethylthioformamide (2a) can be explained. The steric effects of the acid residue on the shielding conditions are discussed on the basis of the n.m.r. spectra of 1-thioisobutyryl- and 1-thiopivalyl-4-methylpiperidine (1c and d). In 1d and in N.N-dimethylthiopivalinamide (2d) rotation around the C-N bond is fast at room temperature. The 2-methyl group in 1-thioacetyl-2-methylpiperidine (1f) is axial.
    Notes: Mit Hilfe von sterisch fixierten 1-Thioacyl-piperidinen werden Modelle für die magnetische Anisotropie-Wirkung des Thioformamid- und Thioacetamid-Systems entwickelt, die die unterschiedliche Zuordnung der Signale der cis- und trans-N-Methyl-Gruppe beim Dimethylthioacetamid und Dimethylthioformamid (2a) erklären. Anhand der NMR-Spektren von 1-Thioisobutyryl- und 1-Thiopivalyl-4-methyl-piperidin (1c und d) wird der sterische Einfluß des Säurerestes auf die Abschirmverhältnisse diskutiert. 1d sowie das N.N-Dimethyl-thiopivalinsäureamid (2d) zeigen bei Raumtemperatur schnelle Rotation um die C-N-Bindung. - Die 2-Methyl-Gruppe des 1-Thioacetyl-2-methyl-piperidins (1f) ist axial angeordnet.
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  • 65
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 219-229 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The compressibility of polyisobutylene and polystyrene above their glass transition temperature is treated as the sum of two parts; a free-volume compressibility and, as originally suggested by Bridgman, a compressibility of the molecules themselves. Two different models are used to treat the free-volume compressibility, and as a result values for the molecular compressibility are estimated. These are in reasonable agreement with other values in the literature. The magnitude of this “molecular compressibility” is then considered in relation to some existing treatments of intermolecular forces. These suggest that intermolecular contacts are more compressible than covalent bonds, and on this basis the observed levels of molecular compressibility can be explained.
    Additional Material: 6 Ill.
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  • 66
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 429-429 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
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  • 67
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 433-462 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The intrachain and interchain vibrations below 900 cm-1 of polydimethylsiloxane (PDMS) have been studied by slow neutron inelastic scattering. A composite motion observed at +25°C for the methyl groups corresponds to nearly free rotation about the threefold axis of symmetry together with a large-amplitude rotation of the entire methyl group. At -123°C, rotation about the threefold axis evolves to a torsional oscillation. The large-amplitude rotation evolves to the skeletal vibrations of a helical conformation. Vestiges of the cooperative skeletal vibrations of the conformation at -123°C persist into the 25°C spectrum. The results indicate the presence of interrupted helical conformations at 25°C, which result from thermal disordering of the low temperature helices. The effects of crosslinking, low molecular-weight oils, and silica filler on the freedom of the methyl group motions and on skeletal vibrations have been determined. The effects of different crosslinking agents and different relative amounts of filler and oil on both the macroscopic physical properties and the observed molecular motions of PDMS can also be interpreted in terms of an interrupted helix.
    Additional Material: 16 Ill.
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  • 68
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 463-473 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Polymers of poly(N-acyl and N-aroyl aziridines) were studied by x-ray diffraction. All the crystalline polymers studied have a triclinic unit cell with two monomer units per unit cell. The a and c (fiber direction) parameters (4.9 and 6.5 A, respectively) are essentially the same for all the cells. The b parameter for the N-acyl polymers, however, increases steadily by a factor of 2 A per methylene group added to the lateral chains. The densities calculated for the unit cells are in agreement with the experimental values obtained. The most probable structure is one in which the molecules assume a planar configuration with the main chain not fully extended. The lateral groups are tilted from the c axis by an angle of 54° in a parallel configuration and alternate on each side of the main chain. This permits these lateral groups to assume packing similar to that of polyethylene. A brief description of the techniques used in this interpretation is included.
    Additional Material: 8 Ill.
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  • 69
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 475-481 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Experiments in which an oscillatory shear flow is superimposed on a steady state shear flow were performed on polyethylene melts by the use of a cone and plate type rheogoniometer. The phase difference between oscillatory shear stress and shear strain increases in all cases and for all frequencies with the increase of the superimposed shear rate. Between ω0, the frequency at which the phase difference is π/2 and the steady shear rate \documentclass{article}\pagestyle{empty}\begin{document}$ \dot \gamma $\end{document}, as found by Booij for polymer solution, the relation ω0 = 1/2 \documentclass{article}\pagestyle{empty}\begin{document}$ \dot \gamma$\end{document}. holds also for polyethylene melts. The significance of this relation is discussed briefly from the viewpoint that the entanglement density decreases with the increase of the imposed shear rate.
    Additional Material: 9 Ill.
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  • 70
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 483-495 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The peak separation in gel-permeation chromatography (GPC) is attributed to the contributions of the steric exclusion and the lateral diffusion processes. The advantage of using the distribution coefficient KGPC of the solute molecule in interpreting the GPC separation mechanism is assessed. The physical significance of KGPC and its relation to measurable GPC parameters are examined in detail. A simple mixing experiment for determining the exclusion effect is described. The results of this experiment, as well as those of the flow rate study, show that the exclusion effect plays the primary role in GPC peak separation. For a column packed with Bio-Rad porous glass of 200 Å designation, the diffusion effect does not contribute significantly to peak separation. However, for the case of a Waters Associates column packed with polystyrene gel of 104 Å designation, both the exclusion and the diffusion effects are shown to be important. A diffusion theory which includes the concept of a restricted diffusion coefficient is proposed to interpret the diffusion effect observed in the polystyrene gel column. The results of the theoretical calculation are found to agree with the observed flow rate dependence of the calibration curve.
    Additional Material: 4 Ill.
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  • 71
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 497-513 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Triplet → singlet energy transfer in nylon 66 film (donor) dyed with proflavine (acceptor) is demonstrated by a decrease of the nylon phosphoresence lifetime and an increase in the proflavine delayed fluorescence/nylon phosphoresence ratio with increasing proflavine concentration. Although the observed donor phosphorescence decay is apparently exponential, the transfer is probably via a long-range dipole-dipole (Förster) interaction, rather than by triplet exciton migration. Arguments are advanced to support this view. Proflavine delayed fluorescence produced by a direct excitation process is also observed. The decay time for this process is roughly an order of magnitude less than that for the sensitized process. All emission intensities are shown to vary linearly with exciting light intensity. Finally, temperature dependence of proflavine delayed fluorescence under different excitation conditions is shown. The efficiency of direct excitation process increases markedly near -50°C as the temperature is increased; the sensitized delayed fluorescence intensity follows that of the nylon phosphorescence with increasing temperature, as expected.
    Additional Material: 7 Ill.
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  • 72
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 515-524 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: An x-ray study of poly(N-butyl isocyanate) (PBIC) was undertaken with the aim of providing the structural information required for the calculation of its ultraviolet absorption spectrum. Well defined diffraction patterns are obtained from powder samples and oriented films of the polymer cast from cyclohexane solution. All the reflections can be satisfactorily indexed in terms of a pseudo-hexagonal unit cell with a = 13.3 Å and c = 15.4 Å. This indexing and the intensity distribution lead to the conclusion that PBIC has a helical structure with a translation of 1.94 Å and a rotation of 135° per monomeric unit (i.e., the c axis corresponds to 8 units in 3 helical turns). In the absence of single-crystal data on closely similar model compounds, a range of possible bond lengths and angles was assumed. The atomic coordinates of the chromophoric group of PBIC were then computed using the restrictions imposed by the helical parameters. From an investigation of all the assumed range of bond lengths and angles, a few closely similar structures having no unacceptably short van der Waals contacts were found. A comparison of calculated and measured densities indicates that there are two molecules per unit cell. Construction of space-filling models of PBIC supports this conclusion.
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  • 73
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 113-122 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Differences in structural parameters, shrinkage, and retractive forces have been compared for nylon 66 tire yarns annealed at several temperatures in silicone oil and in air. It is found that significantly different structural changes occur for oil-annealing and air-annealing. Retractive forces measured in hot oil are characterized by a high initial force, followed by a rapid decay and a second, more gradual, increase which is also followed by a decay at sufficiently high temperatures. In heated air, the first, short-term, retractive force is absent. It is postulated that these differences are due to the different rates of heat transfer at gas-solid and at liquid-solid interfaces, and that rapid heat transfer (as in the case of oil-annealing) promotes two mechanisms of molecular change which are characterized by different degrees of structural parameter change, and by different amounts of shrinkage.
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  • 74
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 143-151 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A theoretical discussion is presented on the mechanisms by which an isolated pulsating air bubble in a viscoelastic solid dissipates its energy. The analysis is limited to the situation where the amplitude of motion is assumed to be sufficiently small that the stress strain relations may be described by linear equations with convected differentiation replaced by ∂/∂t. The theoretical thermal, radiation, and viscous damping constants are calculated for resonant air bubbles in unvulcanized natural rubber; however, the results are typical of elastomers in general.
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  • 75
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 163-170 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A resolution index for gel-permeation chromatograph (GPC) columns is defined by the relation log (RI) = αW, where RI is the resolution index, α is the slope of the calibration curve of logarithm of molecular weight against peak position for narrow polymer fractions, and W is the width of the GPC curves for narrow fractions. This resolution index is calculated approximately for several GPC columns individually and in series combinations by using data obtained on narrow fractions of polystyrene. The index increases with number of columns and with flow rate over a limited range of flow rate, does not vary much with solvent, and does not correlate well with plate count obtained with low molecular weight molecules. It is believed that the resolution index provides an improved indication of the performance of GPC columns.
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  • 76
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 183-200 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Equipment and methods have been developed which allow photomicrographic determination of the stress-strain properties of the individual craze. Serial cyclic tensile tests on polycarbonate crazes are described. Under stress the typical dry polycarbonate craze thickens solely by straining; no adjacent polymer of normal density is converted to craze material. The craze exhibits a yield stress followed by a recoverable flow to roughly 40-50% strain at 6000-8000 psi. On return to zero stress the craze exhibits creep recovery at a decelerating rate. The yield stress and loss factor of each cycle decrease with increasing initial strain and cycles initiating at 50% strain or more show completely Hookean behavior. Creep recovery results in recovery of yield stress and loss factor also. Craze tensile behavior is suggested to be essentially an extension of the craze formation process. Decrease in elastic modulus and yield stress with increasing strain are rationalized in terms of strain-produced decrease in density and resultant increase in stress concentration factor on the microscopic polymer elements of the craze. Polymer surface tension and the large internal specific surface area of the craze are suggested to be important factors in the large creep recovery rates of the craze.
    Additional Material: 10 Ill.
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  • 77
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 231-240 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The birefringence of several biaxially oriented polypropylene films swollen with a number of fluids has been measured and found to exhibit a minimum when plotted against the fluid refractive index, as predicted by the theory of Wiener. However, a discrepancy in the form birefringence behavior is observed when samples of different degrees of crystallinity but the same total birefringence are compared. These results are interpreted in terms of Bullough's theory and suggest that this discrepancy arises because of different morphologies. A refractometric technique was employed that makes possible the simultaneous determination of birefringence and the volume fraction of fluid.
    Additional Material: 6 Ill.
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  • 78
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 249-252 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: NO ABSTRACT.
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  • 79
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 253-254 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
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  • 80
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 2029-2041 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Drawing of single-crystal mats of linear polyethylene has been investigated. Drawing is possible at temperatures higher than about 90°C. The drawing is accompanied by distinct necking, with a large decrease in the thickness of the mat and a very high maximum draw ratio, sometimes over 30. The maximum draw ratio is approximately proportional to the thickness of the lamellae. This behavior strongly suggests the unfolding of chains during drawing. A change of orientation of crystal axes occurs before necking without change of lamellar orientation. The a axis orients in the drawing direction; the b axis orients perpendicular to the direction of drawing; and the chain axis tilts away from the thickness direction of the mat. The structure of films drawn from mats is characterized by a distinct double orientation of crystals. This biaxial orientation in the drawn films has a high degree of correlation with the orientation of crystal axes observed before necking, and suggests that necking takes place in such a way that the chain tilts gradually about the b axis and ultimately unfolds. The postulate of formation of transitory two-dimensional crystals in necking seems useful in explaining the double orientation in the drawn film. The orientation behavior of crystal axes observed before necking is not always similar to that observed in the deformation of a single crystal. The difference is thought to be due to the effect of forces induced by drawing that act in the direction normal to the lamellae within a mat.
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  • 81
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 2043-2050 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: This is the first paper of a series of reports concerning extended-chain crystals of flexible, linear high polymers. The general conditions for crystal growth are discussed. Polymer crystallization is described as a two-step process: nucleation of each crystallizing molecule to a folded-chain conformation, followed by an increase in fold length in a solid-state reorganization step. This reorganization step is enhanced in the case of polyethylene by crystallization at high temperature under elevated pressure. Mechanical deformation during crystallization is also able to produce extended-chain crystals. The most promising method, however, is crystallization during polymerization. Previous work on crystallization of polyethylene under elevated pressure is critically reviewed.
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  • 82
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 2051-2059 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A report on crystallization of polyethylene at elevated pressures to an extended-chain morphology is presented. The crystals have been characterized by electron microscopy and density determination. Pressure, supercooling (temperature), and crystallization time have been varied to find the best conditions for production of perfect crystals. At 10-30°C supercooling completely crystallized polyethylene was obtained between 4.5 and 7 kb crystallization pressure in 1-8 hr. Analysis of fracture surfaces of samples crystallized for different lengths of time shows an increase in size and number of crystal lamellae and an improvement of extended chain crystals in the early stages of crystallization. A further improvement of the less well crystallized material between the lamellae occurs after 15 min of crystallization time.
    Additional Material: 5 Ill.
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  • 83
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1451-1459 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The adiabatic compressibility for two samples (F-1 with DP-3748 and F-2 with DP-2114) of poly(4-vinyl-N-n-butylpyridinium bromide) in aqueous solution has been determined from ultrasonic velocity and density data. The sample (F-1) with the higher degree of polymerization shows comparatively higher velocity and density in solution. However, the evidence for the difference in compressibility is not very decisive. The apparent molal volume ΦV2 and apparent molal compressibility ΦK2 for F-1 are found to be slightly higher than for F-2. In aqueous solution, the decrement of adiabatic compressibility per unit concentration, (β1 - β)/c, is found to be almost constant throughout the entire concentration range, whereas in the presence of excess added electrolyte (1.0M KBr solution), the compressibility decrement shows a decrease with dilution. The latter values are lower than those found in water, since the molecules, in the presence of excess electrolyte, are coiled up more and are less compressible. The ΦV2 and ΦK2 values in water are constant throughout the entire concentration range, as the free counterions formed on dissociation in the dilute region are not solvated and hence contribute little to the compressibility. On the other hand, in the presence of excess KBr (1.0M), the ΦV2 and ΦK2 values show a sharp decrease with increase of polyelectrolyte concentration and finally attain a constant value. This is explained by the fact that because of the formation of a charge-transfer complex between the bromide ion and the polycation, more than the equivalent number of bromide ions is bound, leaving free an equal amount of K+ ions which are solvated and cause the lowering of apparent volumes and compressibilities. Condensation of charges begins at a certain polyelectrolyte concentration, and no further increase of K+ ions is observed. A special situation arises in 0.1M KBr solution. The ΦV2 and ΦK2 values at first increase sharply with increase of polyelectrolyte concentration, but then level off to attain a constant value, at comparatively high concentration. In 2.0% poly(4-vinyl-N-n-butylpyridinium bromide) solution, the concentration of polymer repeat unit (0.08M) is almost equal to the concentration of the added electrolyte (0.1M KBr) used to suppress dissociation. As the polyelectrolyte concentration in 0.1M KBr solution is progressively decreased, more bromide ions are made available for forming the charge-transfer complex with the polycation, leaving the K+ ions free to contribute to the compressibility.
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  • 84
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1483-1487 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Expansion of a small spherical hole in a highly elastic solid is treated theoretically. Both elastic and surface energy terms are considered; the corresponding surface forces are assumed to be additive. The surface energy of the elastomer is assumed to be similar to that of simple liquids. Pressures or triaxial tensions required to inflate pre-existing holes to an indefinitely large size are calculated. Small holes require extremely large pressures, of the order of 1000 atm for holes of 10 Å radius. These results suggest a means of determining the distribution of hole sizes in elastomers and account in principle for experimental observations of cavitation processes. Detachment of the elastomer from a small rigid inclusion is treated in a similar way. The general absence of dilation or cavitation on stretching carbon black-filled elastomers is thus accounted for solely in terms of the small size of these filler particles.
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  • 85
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1033-1057 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The phenomenon of double melting, as manifested by two characteristic endotherms in the melting region on a differential thermal analysis (DTA) scan, has been studied in nylon 66 and polystyrene as a function of sample treatment by annealing or drawing. A variety of techniques were used in these studies including DTA, x-ray diffraction, electron microscopy, and mechanical testing. It is shown that the two endotherms are not caused by a bimodal crystal size distribution, by recrystallization, by orientation changes, or by phase changes. It is proposed that one endotherm is caused by the melting of foldedchain crystals, while the other is due to the melting of less perfect bundle crystals. This view is well supported by the results, especially by the DTA measurements made at different heating rates. Published data on the thermal behavior of annealed and drawn poly(ethylene terephthalate) and on polyethylene crystallized at various pressures may also be explained on this basis if it is allowed that in polyethylene the chains may be more extended.
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  • 86
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1059-1073 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Nylon 66 films exhibiting form I melting behavior show the γ mechanical relaxation at -140°C. Samples which have form II melting behavior do not show this relaxation. The γ relaxation disappears when material having form I behavior is converted to material having form II behavior by annealing or by cold drawing. The form I and form II types of melting behavior are also found in poly(ethylene terephthalate); the interconversions and thermal behavior of the forms are analogous to the nylon 66 case. In poly(ethylene terephthalate), the β relaxation at -40 to -60°C is present only when form I melting behavior is found. Conversion to form II melting behavior by annealing or drawing (80°C) again causes the relaxation to disappear. No β relaxation was found in amorphous polymer. The γ dispersion in nylon 66 and the β dispersion in poly(ethylene terephthalate) can therefore be associated with the crystalline structure responsible for form I melting behavior. Form I melting behavior has been associated with foldedchain crystals based on previous work. It is therefore postulated that the γ dispersion in nylon 66 and the β dispersion in poly(ethylene terephthalate) are associated with motions in the chain folds. This assignment is not inconsistent with the change in the γ dispersion of nylon 66 with the number of backbone CH2 units, since these will affect the fold structure.
    Additional Material: 10 Ill.
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  • 87
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1075-1084 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Raman spectra have been obtained for a typical poly(vinyl chloride) (PVC) of low crystallinity and for a highly crystalline sample of syndiotactic PVC obtained by irradiation of a urea-canal complex. Raman measurements have been made on the three different ordered chain structures possible for ordinary PVC. Extended and folded conformations for the syndiotactic structure and a helical structure for the isotactic molecule obey different selection rules and have different dichroic properties in the infrared and Raman spectra. The observed Raman spectrum is consistent with the model of the extended syndiotactic conformation for crystalline PVC. With the new Raman data some additional assignments can be made in the vibrational spectra of PVC.
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  • 88
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1085-1099 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Measurements of infrared absorbance as a function of temperature down to 77°K have been made on poly(ethylene terephthalate). Transitions observed by other techniques such as torsion pendulum measurements are reflected in the infrared measurements by an abrupt change in the slope of the absorbance versus temperature. The infrared measurements are made on bands of known structural origin so the structures contributing to each transition can be determined. The β transition is shown by infrared to be a composite of two peaks with the lower-temperature portion arising from the amorphous regions and the higher-temperature portion from the crystalline regions.
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  • 89
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1681-1694 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Creep compliance data, J(t), at 35°C for poly(β-hydroxyethyl monomethacrylate), crosslinked by ethylene glycol dimethacrylate in a range of concentration C from 0.0855 to 2.053 × 10-4 mole/cm3 and swollen to various degrees in diluents, were examined for time-concentration superposition. From the dependence of time scale shift factors on v2, the volume fraction of polymer, free volume parameters were calculated for two samples with C = 0.0855 × 10-4 and 0.136 × 10-4 mole/cm3, swollen in the range of v2 from 0.134 to 0.591. Special attention was given to the magnitude of the shift factor on the log J(t) axis and its dependence on concentration, which was found to depend substantially on the crosslinking and the swelling degrees of the samples. This shift was approximately log v2 for lightly crosslinked samples, swollen to a small degree, measured in the neighborhood of the main transition. For higher degrees of crosslinking and/or swelling, the shift was much less and for the most highly crosslinked networks swollen to equilibrium it was even negative. The correction appears to be very sensitive to the strain of the effective chains and to the location on the time scale with respect to the transition and rubberlike zones of viscoelasic behavior. It was found that the parameters of the WLF equation calculated in our previous study from the time-temperature superposition of the creep curves in the rubber-glass transition are valid also for the rubberlike region.
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  • 90
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 1303-1314 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Column chromatographic fractionation of polystyrene was carried out with the methyl-ethyl ketone-methanol system, and effects of various experimental conditions on the fractionation efficiency were studied. For samples with molecular weights below about 6 × 105, neither the temperature gradient (0.7°C/cm), nor the flow rate of solvent (30-270 ml/hr) seriously influences the fractionation efficiency. The effect of temperature gradient becomes apparent only in the high molecular weight region and only if the gradient of the solvent composition is too steep. High flow rates (ca. 125 ml/hr) clearly affect the fractionation efficiency for a high molecular weight sample (Mw = 5.46 × 105). Precipitation chromatography for the fractionation system was calculated from the phase equilibrium data according to the mass transport equation proposed by Schulz et al. The theoretical analysis gives support to the observed dependence of the temperature effect on molecular weight. Comparison of the observed and theoretical relations between elution volume and molecular weight of the fraction, on the other hand, indicates that the process of fractionation is simply elution of polymer off the support without reprecipitation. Certain conditions of polymer deposition on the support are required for optimal results.
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  • 91
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 587-592 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
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  • 92
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 593-600 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A model is proposed to account for the regular twisting of radial ribbons in certain polymer spherulites. The model assumes that the ribbons have crystallographically regular fold surfaces and that growth of the ribbons is nucleation-controlled. The model leads directly to a possible mechanism of spherulitic growth in some polymers.
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  • 93
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    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A general description is given for relations among the optical quantities obtained from fluorescence polarization measurements on bulk polymer stained by fluorescent groups: the moments of distribution of orientations of the fluorescent groups, and those of the structural units of the polymer (chain segments) on which the groups are adsorbed. Two assumptions as to the biaxial symmetry of the bulk polymer and the cylindrical symmetry of the optical anisotropy of the fluorescent element, both for the absorption and emission processes, reduce the intensities of the polarized fluorescence to a 3 × 3 matrix L which is asymmetric (Lij ≠ Lji), as has frequently been observed in experiments. The components of the L matrix are related to those of the J matrix which is so defined as to describe the fourth moments of the distribution of orientations of the structural units on the basis of a random distribution of the rotational angle of the unit about the segment axis. It is found that the use of the method of fluorescence polarization combined with absorption dichroism and/or emission gives the values of the optical anisotropy ratios of the fluorescent unit, and that the effects of the thermal agitation of the structural unit can be separated from the moments of the orientation distribution for the simplest case.
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  • 94
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 743-745 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
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  • 95
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 747-747 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
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  • 96
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 735-742 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It is shown that, at the yield stress, glassy polymers exhibit viscous flow which is in agreement with the generalized theory of Eyring. The study of the yield stress over a wide range of temperatures and strain rates provides evidence on the secondary transitions found by other methods. From our measurements we conclude that every secondary transition corresponds to the liberation of one of the degrees of freedom of a segment of the main chain.
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  • 97
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 747-748 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
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  • 98
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 749-749 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
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  • 99
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 753-762 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Eight epoxy-diamine networks have been formed, diamines with 2 to 12 methylene groups being used as curing agents. Dynamic mechanical tests revealed four transition regions in the dynamic loss modulus/temperature relationship. Two possible explanations for the relaxation of the glycidyl portion of the structure are proposed. One of the relaxations could be due to the breakdown of hydrogen bonds through the hydroxyl and ether groups. The second could be ascribed to the relaxation of the unbonded glycidyl groups or a second relaxation of the glycidyl groups after the breakdown of the hydrogen bonds.
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  • 100
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    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 763-773 
    ISSN: 0449-2978
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Triad tacticity data obtained by NMR analysis have previously been interpreted in terms of two basic statistical models in order to elucidate the stereospecific polymerization mechanism. In this paper the characteristics of these two basic models for stereospecific polymerization, the enantiomorphic-sites (EMS) model, and the polymer-end control (PEC) model, are examined and compared. The tacticity values accessible to the two-parameter EMS model, which includes the influence of the chain end unit, are shown to be highly restricted. Only about 20% of the isotacticity versus syndiotacticity plot is accessible to this model. To this extent the consistency of a set of triad tacticity data with the model can be tested. No such tacticity limits are exhibited by the two-parameter PEC model, which includes the influence of the penultimate unit. Any set of tacticity values which can be interpreted in terms of the two-parameter EMS model can also be interpreted in terms of the two-parameter PEC model.
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