Etude d'un modele d'induction asymetrique: Les oxazolidines α,β-insaturees issues de l'ephedrine

Various oxazolidines were prepared from ephedrine. It was shown that their formation is not general, the reaction is not always stereoselective and can lead to isomerization of the double bond of α,β-unsaturated aldehydes. Some of these oxazolidines were used in stereoselective preparation of β-alkyl aldehydes.     

On the behavior of α-brominated dimethyl o-benzenediacetate toward nitrogen nucleophiles. Part II. Reaction of dimethyl α-bromo-o-benzenediacetate with hydrazines

Dimethyl α-bromo-o-benzenediacetate ( 1 ) condensed with hydrazine and acetylhydrazine to give respectively 1-carbomethoxy-2-amino-1,4-dihydro-3-(2H)isoquinolinone (2) and its N-acetyl derivative ( 9 ). Replacement of the bromine atom of 1 with the N-1-methylhydrazino ( 3 ) and the N-1-phenylhydrazino ( 5 ) groups occurred by allowing 1 to react respectively with methylhydrazine and phenylhydrazine. In the latter case alkylation by 1 at the N-2 also occurred which led to the formation of the 2-phenylaminoisoquinolinone ( 8 ). Derivatives 3 and 5 smoothly cyclized to the 1-earbomethoxy-5(H)-1,2,3,4-tetrahydro-2,3-benzodiazepin-4-ones 4 and 6 . A series of derivatives of 2 were also pharmacologically tested as antiinflammatory and CNS depressant agents.     

Thermal decomposition of copolymers of styrene and halogenated monomers

Copolymers of 1,2,2,2-tetrachloroethyl esters of unsaturated acids and halogenated N-phenyl maleimides with styrene were pyrolyzed; volatile products were analyzed with a mass spectrometer combined with a gas chromatograph. Hydrogen halide and carbon dioxide in the volatile products were determined during the thermal decomposition of copolymers in glass ampoules; the acyl chloride groups were determined in the residues. The thermal decomposition of copolymers of tetrachloroethyl esters with styrene sets in at ca. 230° by the release of chloral from the copolymer and splitting of some of the CCl bonds in the copolymer. The decomposition of copolymers of styrene with halogenated N-phenyl maleimides starts above 300° by depolymerization of the polystyrene chain sections and by splitting of some of the carbon-halogen bonds. At 310 and 500° for copolymers of tetrachloroethyl esters and at 500° for halogenated N-phenyl maleimides, there is radical dehydrohalogenation of the copolymers, with depolymerization of polystyrene blocks and splitting of carbon-carbon bonds in the main chain.     

Chloride, -Hydride and -Borohydride Derivatives of Difluorenyl Thallium(III)

Chloride¹), borohydrides²) and hydrides³) of dicyclopentadienyl thallium (III) and diindenyl thallium (III) have already been reported. The present communication deals with a study on the preparation and characterization of difluorenyl thallium (III) chloride, -hydride and -borohydride.     

Substituent effects in mass spectrometry—II. The effect of substituents on the dissociation of para and meta disubstituted benzenes

The effect of substituents on the activation energy for primary dissociation processes in the molecular ions of mono- and para and meta di-substituted benzenes has been examined. Where the daughter ion retains the substituent group, variation of the energy of activation derives from a combination of the effects of substituents on the ionisation potential of the molecular ion and the appearance potential of the daughter ion. An equation relating the energy of activation for the fragmentation of the molecular ion of a mono-substituted benzene to that of related para and meta di-substituted benzenes is presented.     

19F-Kernresonanzuntersuchungen an Imidoschwefeloxiddifluoriden

¹⁹F nuclear magnetic resonance studies on imidosulphuroxide difluorides Non equivalent fluorine atoms bounded to hexavalent sulphur of the NSOF₂ group in thionyl compounds give extreme AB-spectra.     

Phase diagram and X-ray diffraction analysis of the acrylic acid–acrylamide system

The phase diagram of the acrylic acid–acrylamide system as determined by DTA and the supporting x-ray diffraction data are presented. This diagram shows that the system forms a 1 : 1 addition compound which decomposes above 0°C. There is also one eutectic point at a 67 mole-% acrylic acid composition.     

Interaction of 1, 3-dioxa-2-silacyclanes and their oligomers with alklymagnesium and arylmagnesium halides

Conclusions Cyclic alkoxysilanes — 1,3-dioxa-2-silacyclanes — and their oligomers are decomposed by organomagnesium compounds with the formation of the corresponding silanols (disiloxanes) and tetraalkylsilanols.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1283–1285, July, 1966.     

Über die Konstitution eines Nebenalkaloides aus Adhatoda vasica Nees

Zusammenfassung Das in der vorangehenden Mitt. vonE. Späth undF. Gandini-Kesztler beschriebene Nebenalkaloid wird auf synthetischem Wege mit dem 6-Hydroxy-peganin identifiziert. Die phenolische OH-Gruppe steht also, bezogen auf Formel III, nicht an der Stelle, welche dem CH₃O des Harmins entspricht.