Synthesis of 2-(Tetrazolylacetyl)cyclohexane-1,3-diones

Russian Journal of General Chemistry - 2-(Tetrazolylacetyl)cyclohexane-1,3-diones were synthesized via C-acylation of cyclohexane-1,3-diones with tetrazolylacetic acids in the presence of...     

Spectrophotometric investigation of the hetero-association of caffeine and thiazine dye in aqueous solution

The self-association of thiazine dye, Methylene Blue (MB), and its hetero-association with Caffeine (CAF), were studied in aqueous solution by means of spectrophotometry in the visible range of spectrum. Concentration and temperature dependences of molar absorption of the interacting molecules were used to analyse dynamic equilibrium in solution in terms of two-component model of molecular hetero-association. The magnitudes of equilibrium dimerization and hetero-association constants as well as thermodynamic parameters, enthalpy and entropy, were determined. The calculation of the fraction of different types of associates in the mixed solution, containing Methylene Blue and Caffeine, was done. It was concluded that the hetero-association of Methylene Blue and Caffeine molecules results in lower effective concentration of the dye in solution, which may account for the alteration of its biological activity.     

Substituted 1-(isoxazol-3-yl)methyl-1H-1,2,3-triazoles: Synthesis,palladium(II) complexes,and high-turnover catalysis in aqueous media

New substituted 3-((1H-1,2,3-triazol-1-yl)methyl)-5-arylisoxazoles (aryl?=?Ph, p-Tol) and 2-(5-phenylisoxazol-3-yl)-5-(2-(1-((5-(p-tolyl)isoxazol-3-yl)methyl)-1H-1,2,3-triazol-4-yl)ethyl)-1,3,4-oxadiazole were synthesized by means of click-chemistry procedures. The obtained compounds were used as ligands in preparation of palladium(II) complexes, and the latter proved to be high-turnover-number catalysts for CC cross-coupling reactions under Green Chemistry conditions. One of the ligands was structurally characterized by single crystal X-ray diffraction, and the structure of complexes was determined by ¹H, ¹³C, ¹⁵N NMR spectroscopy and quantum-chemical modeling.