Geschwindigkeit der Verdünnung flüssiger Filme

Colloid and Polymer Science - Die Verdünnung eines mit löslichen Tensiden stabilisierten freien flüssigen Filmes wurde mit hydrodynamischen Methoden unter Berücksichtigung der...     

Synthesis of 3-epistrophanthidin and 3-epistrophanthidol

Chemistry of Natural Compounds - 3-Epistrophanthidin and 3-epistrophanthidol have been synthesized from strophanthidin and strophanthidol with yields of 10 and 40%, respectively. The substances...     

Recyclization of 3-phenacylidene-3,4-dihydro-2H-1,4-benzoxazin-2-one under the influence of o-phenylenediamine

Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, p. 856, June, 1991.     

Polymérisation anionique amorcée par les composés lamellaires du graphite et du lithium

In the present work, we use the binary insertion compound LiC₁₂ to polymerize styrene, methyl methacrylate, butadiene, isoprene, and to copolymerize isoprene and styrene in various hydrocarbon solvents (aromatics and aliphatic) and etheral solvents. We show that the styrene polymerization in aromatic solvents gives better yields than in the etheral solvents, the polymer being atactic. Methyl methacrylate does not polymerize in toluene but does so completely in DME. More generally, the yields of polymerization are better with KC₃₇ than with LiC₁₂ because of the different capacities of the monomer to get into the carbon layers. The polymerization of dienes with LiC₁₂ shows that the microstructures of the polymer obtained in π-or n-donor solvents are similar to the ones obtained by homogenous polymerization with Li cation in such solvents. However, for isoprene in cyclohexane, the results are different. The isoprene styrene copolymers are statistical ones and the mean length of styrene blocks is less than 5. The monomer interaction with the insertion compound and the growing chain geometry between the carbon layers are the facts which control either the stereospecificity of the polymerization or the selectivity of the copolymerization.     

Derivatives of l-H-aziridine-2-carboxylic acid

The reaction of 1,1-dimethylhydrazine with acrylic acid derivatives gave a number of 1,1-dimethyl-2-(2-substituted ethyl)hydrazines, which were quaternized by alkylating agents. The transformations of 1,1,1-trimethyl-2-(2-substituted ethyl)hydrazinium salts in the presence of sodium methoxide were investigated. 2-Cyano-, 2-carbomethoxy-, 2-carbethoxy-, and 2-carbodiethylamidoaziridines and a number of products of decomposition of the starting salts were obtained.