New 6-Arylsulfonyl-1,2-benzoisothiazol-3(2H)-one 1,1-Dioxides Derived from Diphenyl Sulfone Monosulfonyl Chlorides

Various methods were studied for the oxidation of 2-methyl-5-(phenylsulfonyl)benzenesulfamide and its derivatives. The oxidation by sodium dichromate in sulfuric acid was found most efficient. The effects of temperature, concentration, reagent ratio, and time of the oxidation reaction on the yield of the desired product were investigated. Conditions were proposed for obtaining the desired product in yields up to 95%. A synthesis was developed for a series of new saccharin derivatives.     

Directed synthesis of macrocyclic phenylene sulfides

A method has been developed for the directed synthesis of macrocyclic phenylene sulfides with 4–8 phenylene sulfide fragments, by condensation of dihaloaromatic compounds of various types with sodium sulfide or dithiophenate. A combination of this method with high dilution techniques has afforded pure macrocycles in high yields, and the macrocycle with six phenylene sulfide fragments in yields as high as 73%.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 854–858, April, 1990.     

Acoustic-Emission Monitoring of the Deformation and Fracture of Metal–Composite Pressure Vessels

This paper presents the results of experimental studies of damage accumulation in a metal–composite pressure vessel by pneumatic strength tests. The deformation and fracture of the composite structure accompanied by matrix cracking and fiber rupture are analyzed. It is shown that the cracks and fractures generate acoustic-emission signals of various types. The results of acoustic-emission monitoring were used to develop a criterion for ranking vessels according to the strength characteristics of the pressure composite shell.     

Physicochemical properties of 1,2-epoxycyclopentane

Temperature dependences of density, viscosity, and saturated vapor pressure of 1,2-epoxycyclopentane were studied and approximated by interpolation equations. Its refraction index and chromato-mass-spectroscopy data are given.

     

Quantitative determination of olefin oxide, chlorohydrin, and cyclocarbonate in the presence of each other

A procedure was developed for the quantitative determination of olefin oxide, chlorohydrin, and cyclocarbonate simultaneously present in the reaction mixture of the synthesis of cyclocarbonate from olefin oxide and CO₂. To determine olefin oxide, an acetone solution of hydrochloric acid was added to a portion of the reaction mixture, and the excess of hydrochloric acid was titrated with an aqueous solution of potassium hydroxide with visual detection. The concentrations of chlorohydrin and cyclocarbonate were calculated from the data of the potentiometric titration of the same solution to which excess potassium hydroxide was added. Deceased.     

Ionic Liquids in Electrophoretic Separation and Preconcentration Processes

Journal of Analytical Chemistry - Ionic liquids (ILs) are widely used in separation methods such as chromatography and capillary electrophoresis due to their unique properties. This review...     

Kinetics of Reaction between Magnesium Hydroxide and Dimethyl Phosphite

The kinetic of the reaction between magnesium hydroxide and dimethyl phosphite in nitrobenzene was studied.