The bromination of 2-amino- and 2-acetylamino-4-(2-furyl)-thiazoles

The bromination of 2-amino-and 2-acetylamino-4-(2-furyl)thiazoles has been studied, and it has been shown that bromination takes place first in the furan ring and then, with an excess of bromine, also in the thiazole ring in position 5.     

Viscous flow of aqueous solutions of copper sulfate in the temperature range 20–50°C

Apparent molar volume, enthalpy of activation, and Gibbs energy of viscous flow of aqueous copper sulfate solutions were calculated from experimental data. The concentration dependences of the above parameters were analyzed from the standpoint of structural transformations. Original Russian Text V.N. Tseluikin, N.D. Solov’eva, O.G. Nevernaya, 2007, published in Zhurnal Prikladnoi Khimii, 2007, Vol. 80, No. 10, pp. 1747–1749.     

Comparison of combustion sources for sulfur chemiluminescence detection

Three different types of SCD combustion source have been evaluated for use in the chromatographic analysis of atmospheric sulfur compounds. The conventional FID source and the newer inverted burner source were found to be less sensitive and less stable than the flameless design. Overall, the flameless source was superior for use with HRGC-SCD.     

Superoxide-mediated dehydrohalogenation reactions of the pyrethroid permethrin and other chlorinated pesticides

Superoxide generated in DMF readily converts the dihalovinyl group of permethrin and related compounds to a haloethynyl moiety and yields major products from elimination reactions of DDT, $\text{cis}$-chlordane, and 1,2-dibromo-3-chloropropane (DBCP).     

Destruction of carbonyl and hydroperoxide groups in oxidised polypropylene: Effect on photo-oxidation

The effect of destroying carbonyl and hydroperoxide groups in oxidised polypropylene on the subsequent rate of photo-oxidation has been examined using infra-red spectroscopy. The results show that carbonyl groups dominate the rate of photo-oxidation in severely oxidised polymer. In mildly oxidised polymer hydroperoxide groups control the rate, but to a much smaller extent. Destruction of the photo-active carbonyl and hydroperoxide groups in the unoxidised and oxidised polymers by prior photolysis in an inert atmosphere gave rise to some interesting and complex effects on subsequent photo-oxidation. The results indicate that although carbonyl and hydroperoxide groups may control the rates of photo-oxidation of thermally oxidised/processed polymer, their importance as primary photo-initiators is highly questionable. Oxygen-polymer charge transfer complexes appear to be the more likely photo-initiators.     

Heterocyclic analogs of pleiadiene. 70. Synthesis of 6-hydroxy-1,3-diazapyrenes

The regioselectivity of the reactions of perimidine with cinnamic acids in polyphosphoric acid (PPA) depends on the P₂O₅ content. Procedures were developed for the synthesis of 4(9)- and 6(7)-cinnamoylperimidines. Cyclization of the latter under the action of an excess of AlBr₃ was accompanied by dearylation to form 6-hydroxy-1,3-diazapyrene.     

Phase and extraction equilibria in the antipirin-pyrocatechol-water system

Solubility isotherms of the antipirin-pyrocatechol-water ternary system at 25 and 50°C were constructed. A field where two liquid phases are present in equilibrium which results from the protolytic interaction between the components was revealed. The various-composition chemical compounds that formed were isolated preparatively. Interphase distribution of a series of metal ions was studied. The half-extraction pHs of rare-earth metals were found to be linearly related to their ionic radii.     

The determination of bound nitrogen in uranium hexafluoride with an ammonia electrode

Uranium hexafluoride reacts with nitrosyl fluoride (NOF), nitryl fluoride (NO₂F), and nitrogen oxides to form solid compounds such as nitrosyl heptafluorouranate (NOUF₇) and nitryl heptafluorouranate (NO₂UF₇). Since these compounds are undesirable impurities in uranium hexafluoride, a method has been developed for the determination of these nitrogen oxyfluorides in uranium hexafluoride. Uranium hexafluoride is hydrolyzed in a potassium permanganate solution which converts the uranium hexafluoride to uranyl fluoride and the nitrogen oxyfluorides to nitric acid. The nitrate is reduced with aluminum powder to ammonia, which is then measured with an ammonia electrode in a basic solution. The method is relatively interference-free because the electrode is a gas-sensing device. The detection limit is 0.8 μg bound N/g U, and the precision at 3 μg bound N/g U is ± 16%.