Search

In this work, a new application of Cu(II) complex with 3-hydroxy-2-naphtoic acid (Cu-HNA) as a reusable heterogeneous catalyst in the synthesis of tetrahydrobenzo[a]xanthene-11-ones via a one-pot three-component condensation of aryl aldehydes, 2-naphthol, and dimedone in solvent-free condition was reported. At the end of the reaction, with a simple filtration, the catalyst was easily recovered and reused at least five times with no significant loss of its catalytic activity. Appropriate activity and efficient of the catalyst, very good yields, short reaction time, mild and simple work-up, and no use of organic solvents are other benefits of this proposed methodology. [ABSTRACT FROM AUTHOR]

Layered magnesium silicate was modified by water-insoluble chlorin e6 derivatives with two and three ethanolamine fragments on the periphery of the macrocycle by introducing chlorin e6 derivatives into the reaction medium as solutions in hydrochloric acid without the use of organic solvents. The modified layered silicates obtained are characterized by intense fluorescence along with photostability and exhibit photochemical activity in reactions of photosensitized oxidation of model pollutants like xanthene (rhodamine 6G) and azo dyes (methyl orange). [ABSTRACT FROM AUTHOR]

The extraction of trace amounts of U(VI), Th(IV), Am(III), and lanthanides(III) from nitric acid solutions with polyphosphinylbenzenes was studied. The stoichiometry of the extracted complexes was determined, and the influence of the extractant structure, the HNO3 concentration in the aqueous phase, and the nature of organic solvents on the efficiency of metal ions extraction into the organic phase was considered. It was found that compounds with diphenylphosphoryl groups attached directly to the benzene ring in the ortho position in their molecules have the highest extraction ability with respect to actinides and lanthanides. [ABSTRACT FROM AUTHOR]

Isocyanates readily reacts with NaN3 in the presence of ZnCl2 in organic solvents to form the corresponding carbamoyl azides. The formation of carbamoyl azides completed in 5–10 min at room temperature, which prevent the risk of release of hydrogen azide. The obtained carbamoyl azides without isolation can be used for the preparation of 1-substituted tetrazol-5-ones. [ABSTRACT FROM AUTHOR]

The kinetics of the metal exchange reactions of cadmium(II) 5,15-dinitro-2,3,7,8,12,13,17,18-octaethylporphyrinate with copper(II) and zinc(II) chlorides in DMF and DMSO were investigated by the spectrophotometric method. The kinetic parameters of the metal exchange reaction were determined. A possible stoichiometric reaction mechanism was proposed. The effect of the solvent and solvate salt nature on the rate of the metal exchange reaction was revealed. [ABSTRACT FROM AUTHOR]

The reactions of 1-germatranol hydrate with malonic, succinic, maleic, cork, sebacic acids, and bistrimethylsilyl ester of succinic acid, and also of bis(germatran-1-yl)oxane with succinic acid in acetonitrile, water, methanol, and dimethylsulfoxide were studied. In organic solvents, mono- and dicarboxyl-substituted 1-germatranols are formed, which, like 1-germatranol, are reversibly hydrolyzed with water in an acidic medium. Removing water from reaction mixtures due to evaporation and a topochemical reaction increases the yield of esterified 1-germatranol. [ABSTRACT FROM AUTHOR]