Charge transfer complex studies between some non-steroidal anti-inflammatory drugs and pi-electron acceptors

Charge transfer (CT) complexes of some non-steroidal anti-inflammatory drugs, naproxen and etodolac which are electron donors with some pi-acceptors, such as tetracyanoethylene (TCNE), 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ), p-chloranil (p-CHL), have been investigated spectrophotometrically in chloroform at 21 degrees C. The coloured products are measured spectrophotometrically at different wavelength depending on the electronic transition between donors and acceptors. Beer's law is obeyed and colours were produced in non-aqueous media. All complexes were stable at least 2 h except for etodolac with DDQ stable for 5 min. The equilibrium constants of the CT complexes were determined by the Benesi-Hildebrand equation. The thermodynamic parameters DeltaH, DeltaS, DeltaG degrees were calculated by Van't Hoff equation. Stochiometries of the complexes formed between donors and acceptors were defined by the Job's method of the continuous variation and found in 1:1 complexation with donor and acceptor at the maximum absorption bands in all cases.     

An efficient hydrogenation of various alkenes using scrap automobile catalyst

An efficient, easy, cheap, convenient, and safe procedure for the reduction of various alkenes to the corresponding alkanes is developed by using scrap automobile catalyst as an efficient hydrogenation catalyst. This procedure not only gives high yields, but also allows recycling of automobile wastes as a catalyst in organic reactions and is representative of green chemistry.     

Synthesis,antioxidant activity and SAR study of novel spiro-isatin-based Schiff bases

Molecular Diversity - A new series of 21 Schiff bases of spiro-isatin was synthesized, and their DPPH, CUPRAC and ABTS cation radical scavenging abilities were investigated for antioxidant...     

Selective anomeric deacetylation using zinc acetate as catalyst

An alternative method has been developed for the anomeric deacetylation of fully acetylated carbohydrate derivatives using zinc acetate dihydrate as a catalyst in methanol under mild conditions. The experimental simplicity, low cost, acceptable yield, use of a readily handled acidic catalyst, and the environmentally benign nature are some of the advantages of this method.     

Solvent-free synthesis of dihydropyrimidinones catalyzed by alumina sulfuric acid at room temperature

A simple, efficient and practical procedure for the Biginelli reaction using alumina sulfuric acid (ASA) as a novel acid catalyst is described under solvent-free conditions. The catalyst exhibited remarkable reactivity at room temperature. The method offers several advantages including high yields, environmentally friendly procedure, short reaction times and simple work up procedure.