Letters in Organic Chemistry - Volume 10, Issue 4, 2013

The re-emergence, in the recent years, of cyclooxygenase as a biological target in therapeutic areas other than inflammation is likely to require new optimized leads, particularly suited for the requirements of specific drug development programs. We developed a convenient synthesis of the known imidazole-based selective COX-2 inhibitors bearing primary sulphonamide and methyl sulfone substituents, via Pd-catalyzed imida Read More

A synthesis of N-substituted 1-alkyl and 1-aryl 3-aminoisoquinolines by cyclocondensation of 2- acylphenylacetonitriles with aliphatic and aromatic amines using P2O5/SiO2 as catalysts is described. Selectivity, simplicity of operation and easy work-up are some advantages of this method.

ZnS-nanoparticles, as recyclable heterogeneous catalyst, efficiently promoted in the synthesis of spiro[pyrrolidine-2,3'-oxindole] derivatives through three-component reaction of isatin, α-amino acid and phenothiazinyl chalcones. An azomethine ylide generated by decarboxylative condensation of isatin with α-amino acid, and chalcones have been used as trapping dipolarophiles. ZnS nanoparticles were synthesized by aqueous che Read More

A facile, high efficiency microwave-assisted method was established for synthesizing novel quinoline lactones. All the synthesized compounds were characterized by 1H NMR, infrared spectrum, mass spectrum and elementary analysis. The preliminary bioassays result tests indicated that part of compounds have certain activity against Escherichia coli.

New ten macrocycles 5a-c and e-k and one cryptand 5d were synthesized by the reaction of diamine compounds 4a-k with N,N'-bis(2-chloroacetamido)-2,6-diaminopyridine (BCDP) 3 in the presence of K2CO3 and KI in good to high yields. Also the template effects of cations such as Na+, K+, K+/KI and Cs+ on the reaction yields for macrocycles (4a-c and I, k) were investigated. In this study it is found that size matchi Read More

In this work we investigated the synthesis of methyl esters (biodiesel) of oil obtained from the microalgae Scenedesmus dimorphus through the hydro-esterification process (esterification process preceded by hydrolysis) as possible alternative for conventional processes. There is interest to develop new raw materials and reactions processes that favors the maintenance of biodiesel in the global energy matrix.

The surface of glass micro-particle (GMP) was functionalized with β-cyclodextrin (→ GMP-β-CD) and was characterized by X-ray photoelectron spectroscopy (XPS). GMP-β-CD was used as a phase transfer catalyst for click reactions of aromatic azides with terminal acetylenes. For click reaction of benzyl azide and phenyl acetylene, reaction time was decreased from 5.8 h to 10 min when 0.8g GMP-β-CD /mmol of benzyl Read More

new aromaticity index is proposed based on the energy of π orbital [π1 + (π1 - π2) + (π1 - π3)]. Calculations have been performed on aromatic and heteroaromatic compounds by using DFT method at B3LYP/6-311G+(d,p) level. This new index has been tested on 6π electron compounds and compared with the experimental resonance energy (ERE), the Bird index (Ix), the molar magnetic susceptibility (XM), the aromatic stabili Read More

Twelve 4-arylmethylidene-2-phenyl-4H-oxazol-5-ones were prepared in excellent yield by sonicating a mixture of an araldehyde, hippuric acid and acetic anhydride in the presence of a green heterogeneous NanoMgO as a basic catalyst. The catalytic activity of NanoMgO was found to be higher compared with bulk MgO powder under the same conditions. This method provides several advantages such as short reaction time, high Read More

Cholinesterase inhibitors play an essential role in the treatment of Alzheimer’s disease. Since their first introduction over a decade ago, they are an indispensable part of Alzheimer's disease therapy and remain at the forefront of scientific interest worldwide. In this manuscript new analogs of THA and 7-MEOTA were designed, synthesized, and evaluated for their inhibitory activity against both acetylcholinesterase and butyrylch Read More

Silica sulfuric acid (SSA) was firstly used as an efficient catalyst to promote the synthesis of rctt configurational calix[4]resorcinarenes via one-pot condensation between resorcinol and aromatic aldehydes. The structure of 4- cyanophenyl-calix[4]resorcinarene (3b) has been determined by single crystal X-ray diffraction.

A simple and efficient protocol for the synthesis of highly substituted xanthenes is developed through the condensation of β-naphthol, aldehyde, and 5,5-dimethylcyclohexane-1,3-dione with zirconium oxychloride octahydrate as a catalyst under solvent free condition at 120°c.

A facile synthesis of some spirobiindane based bis-flavanones and bis-chroman-4-ones was achieved by employing Kabbe reaction on spirobiindane bis-acetophenone as the key step.