BACKGROUND α-Bromination of the side chain of aromatic ketones using NBS in the presence of p-toluenesulfonic acid (p-TsOH) in acetonitrile is very common. However, regioselective bromination of bis and tris(ω-bromoacetophenones) with NBS in the presence of p-TsOH in acetonitrile under microwave irradiation is quite novel. The bis- and tris(ω-bromoacetophenones) are used in synthesis of bis and...

Background and objectives: Stevia rebaudiana Bertoni is a herbaceous and a small shrub of the Compositae family. It is native to certain regions of South America. Since 1970s, Stevia extracts have been extensively used in many countries as a sugar substitute. Stevia is cultivated in many countries: Paraguay, USA, Mexico, Central America, Japan, China,...

silver nanoparticles (nps) have been the subjects of researchers because of their unique properties ( e.g., size and shape depending optical, antimicrobial, and electrical properties). a variety of preparation techniques have been reported for the synthesis of silver nps; notable examples include, laser ablation, gamma irradiation, electron irradiation, chemical reduction, photochemical methods...

We have performed in situ quasielastic neutron scattering (QENS) measurements on zeolite-guest systems under microwave irradiation, for comparison with corresponding simulations. Both experiment and simulation reveal selective heating of methanol in silicalite, but little to no heating of benzene in silicalite. Effective translational and rotational temperatures extracted from QENS data under m...

Zn/AcOH on silica gel converts a range of structurally different sulfoxides to their corresponding thioethers in excellent yields under microwave irradiation. It has been found that chemoselective deoxygenation of sufoxides can be achieved in the presence of other reducible functional groups such as acetals, acids, amides,   esters, ketones and nitriles.  

Sulfonic acid functionalized SBA-15 as a nanoporous acid catalyst was used in the synthesis of 2-Aryl benzoxazoles 4 by the condensation of 2-aminophenol 1 and benzoyl chlorides 2 under microwave irradiation in solvent free reaction conditions. The advantages of this methodology are good product yields (60-98%), being environmentally benign, short reaction times and easy work up.

Focused microwave irradiation has been applied to a multistep synthetic sequence of reactions designed to generate benzimidazolyl quinoxalinones using a soluble polymer support. They were obtained by the ipso-fluoro (S(N)Ar) displacement of the immobilized ortho-nitro fluoro benzimidazoles with chiral alpha amino esters under microwave irradiation. Intermediate chiral organic-polymer conjugates...

Reducing the consumption of cement with simultaneous utilizing waste materials as cement replacement is preferred for reasons of environmental protection. Blended cements consist of different supplementary cementitious materials (SCMs), such as fly ash, silica fume, Ground Granulated Blast Furnace Slag (GGBFS), natural pozzolans, etc. These materials should be chemically activated to show effec...

4-Heteroarylidene-2-phenyl-1,3-oxazol-5(4H)-ones were prepared by reactions of hippuric acid with substituted furan-2-carboxaldehydes or furo[b]pyrrole type aldehydes. The reactivity of various furan-2-carboxaldehyde derivatives in this reaction is discussed. The effect of microwave irradiation on some condensation reactions was compared with "classical" conditions. The results show that microw...

Synthesis of fullerene oxides[C70(O)n] (n=1~3 or n=1) by fullerene [C70] and several oxidants such as 3-chloroperoxy benzoic acid, chromium(VI) oxide, benzoyl peroxide, trichloroisocyanuric acid take place under microwave irradiation. The MALDI-TOF MS, UV-visible spectra and HPLC analysis confirmed that the products of fullerene oxidation are [C70(O)n] (n=1~3 or n=1). Keyword : A.Fullerene oxid...