A highly efficient and simple method for the preparation of α,α´-bis(arylidene)cycloalkanones under solvent-free conditions has been developed. The crossed-aldol condensation of cycloalkanones (1 eq.) with arylaldehydes (2 eq.) in the presence of 2.5 mol% of ionic liquid 1,3-disulfonic acid imidazolium hydrogen sulfate {[Dsim]HSO4} afforded the title compounds in high yields and short reaction ...

in this research, we have developed cheap recyclable and task-specific acidic ionic liquids (ails) 1-hydrogen-3-methylimidazolium hydrogen sulfate [hmim]hso4, 1-hydrogen-3-methylimidazolium chloride [hmim]cl, 2-pyrrolidonium hydrogensulfate [hnhp]hso4 and applied them in acid catalyzed synthesis of quinoxaline derivatives from 1,2-phenylendiamines and 1,2-dicarbonyl compounds. the products coul...

Crystalline solids, co-existing in equilibrium with the 3-methyl-1H-imidazolium bromohydrogenates(I) ionic liquid, have been characterised by X-ray diffraction analysis. The Brønsted acidic, homo-conjugate [H(2)Br(3)](-) anions presented are discussed in terms of their structure and reactivity, in efforts to advance the understanding of Brønsted acidity in ionic liquid media.

Background: Organic dyes are used for a wide variety of purposes including their applications in textiles, foods, printing cosmetics and pharmaceuticals. Thus, these are industrially very important and their analysis is always required before putting to particular use. Methods: To develop the extremely efficient thin layer chromatographic system for the resolution of co-existing dyes, the silic...

In the crystal of the title compound, C(15)H(34)N(+)·CH(3)SO(4) (-), the cations and anions are joined together via strong N-H⋯O hydrogen bonds into layers parallel to (001).

Sulfate ions did not inhibit methanogenesis in estuarine sediments supplemented with methanol, trimethylamine, or methionine. However, sulfate greatly retarded methanogenesis when hydrogen or acetate was the substrate. Sulfate reduction was stimulated by acetate, hydrogen, and acetate plus hydrogen, but not by methanol or trimethylamine. These results indicate that sulfate-reducing bacteria wil...

The title salt, C(12)H(9)N(2) (+)·CH(3)O(4)S(-), contains an almost planar phenazinium cation [largest deviation from the least-squares plane = 0.040 (3) Å] and a methyl sulfate anion. The sulfate moiety of the latter is disordered over two sets of sites in a 0.853 (5):0.147 (5) ratio. In the crystal, the cations and anions are arranged alternately in layers parallel to (010). The cations pack ...

Imidazolium-based ionic liquids that contain perrhenate anions are very efficient reaction media for the epoxidation of olefins with H2O2 as an oxidant, thus affording cyclooctene in almost quantitative yields. The mechanism of this reaction does not follow the usual pathway through peroxo complexes, as is the case with long-known molecular transition-metal catalysts. By using in situ Raman, FT...

In the title molecular salt, 3C5H12N(+)·HSO4 (-)·SO4 (2-), each cation adopts a chair conformation. In the crystal, the hydrogen sulfate ion is connected to the sulfate ion by a strong O-H⋯O hydrogen bond. The packing also features a number of N-H⋯O hydrogen bonds, which lead to a three-dimensional network structure. The hydrogen sulfate anion accepts four hydrogen bonds from two cations, where...