Die polymerisation von lactamen, 86. Verzweigung der autopolymerisationsprodukte von 8-octanlactam

Assumed branching of polymer chains of poly(8-octane lactam) was proved from the study of solution properties of polymers prepared under the conditions of autopolymerization in the temperature range 240–260°C. The amidine structures in the polymer chains which were found out by hydrazinolysis are not in relation to the branching in the full extent.     

Beiträge zur galvanisierung von polymeren, 7. Metallisierung von epoxidharzen mit hilfe von haftvermittlern

Epoxy resins can be coated with a metal after being covered with a platable adhesive. Such an adhesive consists of a partly epoxidized styrene-butadiene-styrene block copolymer, an epoxy prepolymer and an amine curer. The contents of these substances in the mixture and the nature of the amine influence the peel strength of the metal layer. The maximum peel strength with a value of about 45 N/25 mm was obtained after using a low molecular weight amine, while values of only about 10 N/25 mm could be obtained with amines of higher molecular weight.     

Lichtinduzierte Polymerisation, 4. Pfropfcopolymerisation von Methylmethacrylat auf Polyethylenoxid in Gegenwart von Chinolinderivaten

When using poly(ethylene oxide) (PEO) as a polymeric hydrogen donator, grafted polymerization products are obtained upon photoinduced polymerization of methyl methacrylate with quinoline derivatives and PEO. The separation of these graft copolymers from the simultaneously formed homopolymeric poly(methyl methacrylate) (PMMA) and the remainder of not converted PEO can be achieved by subsequent extraction with ethyl acetate and methanol. With that determination of graft yield, degree of grafting, grafting success, and grafting height are possible.     

Die polymerisation von lactamen, 50. Die polymerisation von 8-octanlactam in gegenwart von wasser in niedrigen konzentrationen

The polymerization of 8-octanelactam in the presence of 0,15–0,95 mol-% water at 250°C was studied. The kinetic data obtained gave evidence for a different function of water at concentrations up to 0,35 mol-% and higher concentrations. With respect to the results of the end-group analysis of the polymers, which were prepared without added water or other initiators (autopolymerization), a cationic mechanism for the polymerization of 8-octanelactam in the presence of water up to 0,35 mol-% was suggested.     

Nucleoside von Fluorzuckern,XV. Synthese von Thymin-Nucleosiden der 6-Fluor-D-glucopyranose und 6-Fluor-D-galaktopyranose

Nucleosides of Fluorine Carbohydrates. XV. Synthesis of Thymine Nucleosides of 6-Fluoro-D -glucopyranose and 6-Fluoro-D -galactopyranose 1-β-D -glucopyranosyl thymine 1 and 1-β-D -galactopyranosyl thymine 13 react with equimolar amounts of tosyl or mesyl chloride to give predominantly the 6′-O-sulphonyl derivatives 6 and 7 or 14 and 15 . Simultaneously small amounts of the 2′,6′-di-O-sulphonyl derivatives 4 and 5 are obtained. The tosyl derivative 6 reacts easily with alkali fluoride to give the 6′-deoxy-6′-fluoro nucleoside 10 . In contrast to the glucose series the corresponding conversion of the 6′-sulphonyloxy-galactose derivatives is difficult to achieve. The condensation of 2,3,4-tri-O-acetyl-6-O-tosyl-D -glucopyranosyl bromide 2 or 6-deoxy-6-fluoro-1,2,3,4-tetra-O-acetyl-D -galactopyranose 18 with 2,4-bis-O-trimethylsilyl thymine 3 affords, after deacetylation, 6 and 1-(6′-deoxy-6′-fluoro-β-D -galactopyranosyl)thymine 20 , respectively.     

Photooxidation von Leukofarbstoffen. III. Sensibilisierte Photooxidation von Leukofluoreszein

Photooxidation of Leuco Dyes. III. Sensitized Photooxidation of Leuco Fluorescein Quantum yields of the sensitized photooxidation of leuco fluorescein are reported. Fluorescein and benzophenone were found to be efficient sensitizers of photooxidation of leuco fluorescein. There is a characteristic dependence of quantum yields on concentration of leuco fluorescein and oxygen in the solution. The results are discussed on the basis of reaction scheme proposed for the sensitized formation of fluorescein.     

Massenspektroskopie von Naturstoffen. XIII. Massenspektroskopische Untersuchungen von A-nor-Allobetulanen

Mass Spectroscopy of Natural Products. XIII. Mass Spectroscopic Investigations of A-nor-Allobetulanes The mass spectroscopic fragmentation behaviour of A-nor-allobetulanes with several substituents at C-2 is discussed. The skeleton fragmentation is comparable to that of C-3-substituted allobetulanes. The nature of the substituent at C-2 influences both the abundance of typical skeleton fragments and the formation of specific ions.     

Synthese von cyclischen N,O- bzw. N,S-Heterocyclen durch Kondensation von Fettsäurealkylolamiden mit Carbonylverbindungen bzw. Phosphorpentasulfid

Synthesis of Cyclic N,O- and N,S-Heterocyclic Compounds by Condensation of Fatty Acid Alkylolamides with Carbonyl Compounds and Phosphorous Pentasulfide Respectively Fatty acid alkylolamides of the type RCONHCHR¹ (CH₂)_n CHR₂OH (R: alkyl rest with 2 to 17 carbon atoms, cycloalkyl or aryl rest; R₁ and R₂: alkyl rests with 1 to 3 carbon atoms or hydrogen; and n = 0–2) are converted by acidic condensation with lower aliphatic or aromatic aldehydes and ketones respectively to mono- and disubstituted N-acyl-oxazolidines, N-acyl-1,3-tetrahydrooxazines and N-acyl-1,3-hexahydrooxazepines. Furthermore, new types of 2-alkyl-4,5-dihydro-6H-1,3-thiazine (n = 1) besides monoalkyl substituted Δ-2-thiazolines (n = 0) were obtained from fatty acid alkylolamides by condensation with P₂S₅. A large number of the compounds prepared show excellent bacteriostatic and fungistatic action.     

Massenspectroskopie von Naturstoffen. XV. Vergleichende Kationen-Anionen-Massenspektroskopie von Azidogibberellinen

Mass Spectrometry of Natural Products. XV. Comparative Positive-Negative Ion Mass Spectrometry of Azidogibberellins The fragmentation behaviour of 1-azido-3-hydroxy-gibberellin derivatives has been studied by means of positive and negative ion mass spectrometry, high resolution and metastable transitions. The results obtained allow a mass spectrometric distinction to be made between epimers with different stereochemistry of the ring A substituents.     

Substituenteneffekte in den 13C-NMR-Spektren von diastereomeren Chalkondihalogeniden. V. Synthese,Stereochemie und Spektroskopie von Chalkonfluorhydrinen

Substituent Effects in ¹³C- N. M. R. Spectra of Diastereomeric Chalcone Dihalogenides. V. Synthesis, Stereochemistry and Spectroscopy of Chalcone Fluorohydrines Chalcone fluorohydrins 1 and diastereomeric pairs of chalcone chlorohydrins 2 as standards are investigated in the i.r., ¹H, ¹⁹F, and ¹³C n m. r. spectroscopy field. The substituent dependence of the spectral parameters is discussed. The assignment of conformation and configuration on the basis of vicinal ¹H ¹H, ¹H ¹⁹F, and ¹H ¹³C coupling constants is determined.