Potential and Current Distributions in Chlorine Diaphragm Electrolyzers with Gas Removal from the Back Side of External Electrodes and Possibility of Electrolysis Intensification

The cell voltage balance components of monopolar and bipolar electrolyzers were analyzed on the basis of calculations in terms of a mathematical model of the potential and current distributions along the cell height and tests of a laboratory electrolyzer of industrial height. Ways to diminish energy expenditure and to intensify diaphragm electrolysis of aqueous sodium chloride solutions were substantiated theoretically and experimentally.     

Three-component one-pot total syntheses of glyantrypine, fumiquinazoline F, and fiscalin B promoted by microwave irradiation

A microwave-promoted three-component one-pot reaction has been developed to provide access to the core pyrazino[2,1-b]quinazoline-3,6-dione (1) scaffold, which is common to several families of alkaloids with significant biological activities. By adapting this synthetic strategy through the use of selected Boc-amino acids and amino acid esters, we have accomplished highly efficient and concise total syntheses of glyantrypine (2), fumiquinazoline F (3), and fiscalin B (5), achieving overall yields of 55, 39, and 20%, respectively.     

Haloheterocyclization of 2-allyl(propargyl)oxyquinoline-3-carbaldehydes

The reaction of 2-allyl(propargyl)oxyquinoline-3-carbaldehydes with halogens gives 1-bromomethyl(bromomethylidene)-4-formyl-1,2-dihydrooxazolo[3,2-a]quinolinium halides. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 8, pp. 1204–1207, August, 2007.     

Synthesis of 7-formyl-2-methyl-4-oxo-3,4-dihydropyrrolo[3,2-d]-pyrimidine and some other 7-substituted derivatives

A method that utilizes the Vilsmeier reaction to form a pyrrole ring was developed for the preparation of the previously unknown 7-formyl-2-methyl-4-oxo-3,4-dihydropyrrolo[3,2-d]pyrimidine from 2,6-dimethyl-5-amino-4-oxo-3,4-dihydropyrimidine. The nitrile, which was converted to the amide, was obtained from the oxime of the synthesized aldehyde. 7-Unsubstituted pyrrolopyrimidine was synthesized by oxidation of the aldehyde to the corresponding acid and subsequent decarboxylation. The IR and PMR spectroscopic data are presented.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1672–1674, December, 1977.     

Neutronenabsorption Bei der Aktivierungsanalyse von Kadmium und Kadmiumtellurid

A calculation method of self-shielding coefficients of interesting elements in samples of any forms is given for the neutron activation analysis of cadmium and its compounds. The determination of ten elements in cadmium telluride using radiochemical separation and γ spectrometry is described.      

N,N-dimethyl-N-(methylferrocenyl)amine as a bifunctional component of initiating systems for free-radical polymerization of methyl methacrylate

The specific features of free-radical polymerization of methyl methacrylate in the presence of a new initiating system, benzoyl peroxide-N,N-dimethyl-N-(methylferrocenyl)amine, are studied. Mutual influence of the ferrocene and amino groups on the kinetic parameters of polymerization and on the microstructure of the resulting polymers is revealed. The polymer formed in the presence of this initiating system is shown to have a predominantly syndiotactic structure.     

Separation and determination of ephedrine alkaloids and tetramethylpyrazine in Ephedra sinica Stapf by gas chromatography-mass spectrometry

A simple, sensitive, and reliable method using gas chromatography (GC)-mass spectrometry (MS) is developed for the simultaneous determination of ephedrine alkaloids and 2,3,5,6-tetramethylpyrazine (TMP) in Ephedra sinica Stapf. The sample is extracted with ethyl ether and submitted to GC-MS for identification and quantitation without derivatization. The column used for GC is an HP-5 (30.0 m x 250 microm x 0.25 microm, 5% phenyl methyl siloxane), and the carrier gas is helium. The detection limits for ephedrine, pseudoephedrine, and TMP are 0.4 ng 0.7 ng, and 0.02 ng (signal-to-noise ratio of 3), respectively. The reproducibility of the total procedure is proved to be acceptable (RSD < 2%), and the recoveries are above 93%.