Catalytic Method for Synthesis of Aspirin by a Green,Efficient and Recyclable Solid Acid Catalyst (Preyssler's Anion) at Room Temperature

Synthesis of aspirin at room temperature via O‐acetylation of salicylic acid in the presence of Preyssler type heteropolyacids has been investigated in order to contribute toward clean technology, which is the most important need of the society. All of the catalysts are recyclable and reusable.     

Microwave-assisted synthesis of new pyrimido[4′,5′：4,5]thiazolo[3,2-α] benzimidazol-4（3H）-one derivatives in solvent-free condition

Microwave-assisted synthesis of new 2-arylpyrimido[4′,5′：4,5]thiazolo[3,2-α]benzimidazol-4（3H）-ones from 3-aminothia- zolo[3,2-α]benzimidazol-2-earboxamide and aroyl halides in solvent-free condition is described. In comparison with classical conditions the reactions are faster and the yields are higher under microwave irradiation.     

A Review in Linear Alkylbenzene (LAB) Production Processes in the Petrochemical Industry

Russian Journal of Applied Chemistry - Linear alkylbenzene (LAB) is a cost-effective and biodegradable intermediate in the production of detergents and surfactants. Recently, due to the spread of...     

Electrochemical study of Cu2O/CuO composite coating produced by annealing and electrochemical methods

The electrochemical behavior of a copper oxide electrode produced by annealing and electrochemical methods was studied in an acetonitrile solvent by means of the cyclic voltammetry method. The presence of different peaks of oxidation and reduction produced by repeating the potential scans, numerous variations in the current, and shifts of peak potentials in consecutive cycles have been justified. Voltammograms proved that various oxidation species can be produced in solid-deposited forms of Cu₂O_s and CuO_s and dissolved forms of Cu(II)_sol and Cu(I)_sol ions. The experimental results indicated that higher amounts of Cu₂O_s than CuO_s can be produced in the process of copper electrode annealing. Also, the nature of copper species is responsible for different peak currents in the cyclic voltammograms, characterized by UV–Vis and XRD spectrometric methods.

     

Keggin Heteropolyacid Catalyzed Synthesis of Isoxazolo[5,4-d]pyrimidine-4,6(5H,7H)-diones at Room Temperature

Isoxazolo[5,4‐d]pyrimidine‐4,6(5H,7H)diones 2a – 2f have been synthesized from the reaction of ethyl 5‐amino‐3‐methyl‐4‐isoxazole carboxylate ( 1 ) with aryl isocyanates in the presence of Keggin heteropolyacid H₃[PW₁₂O₄₀] as a green solid acid catalyst at room temperature in a one‐pot process in good yields.     

Sulfonato-encapsulated bismuth(III) oxido-clusters from Bi2O3 in water under mild conditions

Treatment of Bi(2)O(3) with the acids; S-(+)-10-camphorsulfonic, 2,4,6-mesitylenesulfonic and sulfamic, under sonication at room temperature in water for 2-4 h, results in the formation and subsequent crystallisation of polynuclear bismuth oxido-clusters; [Bi(18)O(12)(OH)(12)(O(3)S-Cam)(18)(H(2)O)(2)], [Bi(38)O(45)(O(3)S-Mes)(24)(H(2)O)(14)] and [Bi(6)O(4)(OH)(4)(O(3)SNH(2))(6)].     

Catalytic Synthesis of Fused 1,4-Dihydropyridines and 1,4-Dihydropyridine Derivatives Using Preyssler Heteropolyacids Catalyst

An efficient and convenient method for the synthesis of 1,4-dihydropyridines from β-dicarbonyl compounds, aldehydes, and ammonium acetate and the synthesis of fused 1,4-dihydropyridines from dimedone in the presence of Preyssler heteropolyacid catalyst are reported under reflux conditions with good to excellent yields. Preyssler heteropolyacid catalyst is easily prepared, stable (up to 300 °C), reusable, efficient, green and inexpensive.     

Microwave-assisted synthesis of new pyrimido[4′,5′:4,5]thiazolo[3,2-a]benzimidazol-4(3H)-one derivatives in solvent-free condition

Microwave-assisted synthesis of new 2-arylpyrimido[4′,5′:4,5]thiazolo[3,2-α]benzimidazol-4(3H)-ones from 3-aminothia- zolo[3,2-α]benzimidazol-2-carboxamide and aroyl halides in solvent-free condition is described.In comparison with classical conditions the reactions are faster and the yields are higher under microwave irradiation.     

Mesomorphism dependence on central bridge and tail ended polar group

Abstract

Severe operation conditions in the agriculture industry and numerous influencing factors complicate the selection of a contact material for switching devices. Attempts have been made to change the Ag-CdO contact material to a less toxic one. Environmentally friendly copper-base contact materials have been created for devices, which operate in agricultural electric systems, meanwhile being low-cost and with pre-set level of reliability in terms of transient resistance.