Combination of ultrasound and heat has been used for the oxidation of some ethyl 3,4-dihydropyrimidin-2(1H)-one-5-carboxylates to their corresponding ethyl pyrimidin-2(1H)-one-5-carboxylates by using potassium peroxydisulfate in aqueous acetonitrile. An ultrasonic probe of 24 kHz frequency has been used for this study. Whereas the use of ultrasound increases the rate of reactions compared with reactions at reflux conditions, the nature of 4-substituent on the dihydropyrimidinone ring affects also the rate of reaction.

The gas sweetening process requires an efficient solvent with strong absorption capability to capture acid gases from flue gas. Absorption can be strong by a chemical formation (as "chemical" absorption) or simple with no chemical reactions (as "physical" absorption). The purpose of the present study was to compare the CO 2 solubility of the chemically absorbing ionic liquid, 1-butyl-3-methylimidazolium acetate ([Bmim][Ac]), with the physically absorbing ionic liquid, 1-butyl-3-methylimidazolium tetrafluoroborate ([Bmim][BF 4 ]), as a function of temperature at (298.15 to 318.15) K for pressure up to 50 bar. In addition, the CO 2 solubility for binary mixtures containing 75% [BF 4 ] are measured over the same temperature range. Henry's law constants are reported for the solubility of CO 2 in the studied pure and mixed ionic liquids. Furthermore, the density of mixed ionic liquids is experimentally measured in T = 298.15 K, 308.15 K, and 318.15 K. Finally, the partial molar thermodynamic functions of solvation containing Gibbs free energy, enthalpy, and entropy are evaluated based on the variation of Henry's law constants (as a representative of solubility) with temperature.

No abstract

No abstract

No abstract

No abstract

No abstract

No abstract