nano silica sulfuric acid as a solid acid, was described to be an effective catalyst for one-pot three-component reaction of kojic acid, aryl aldehydes and indoles for the preparation of 2-substituted aryl (indolyl) kojic acid derivatives. the catalyst was prepared by combination of chlorosulfonic acid to nano silica gel. the size of nanoparticles were observed with sem.all prepared compounds w...

We report on a diastereoselective synthesis of six derivatives of caffeoyl- and feruloyl-muco-quinic acids. All the muco-quinic acid derivatives were obtained in excellent yield in five steps starting from quinic acid, caffeic acid and ferulic acid. Allyl ether protection of trans-hydroxy cinnamic acids was here introduced to chlorogenic acids synthesis. We show that muco-quinic acid derivative...

A model for computing image ow in image sequences containing a very wide range of instantaneous ows is proposed. This model integrates the spatio-temporal image derivatives from multiple temporal scales to provide both reliable and accurate instantaneous ow estimates. The integration employs robust regression and automatic scale weighting in a generalized brightness constancy framework. In addi...

Barium salts of dibenzylidene cystines 8a-c were obtained from the reaction of Lcystine with benzaldehyde or its derivatives in the presence of barium hydroxide. Their reduction with zinc and hydrochloric acid in methanol yielded the Narylmethylcysteines ?9a-c?. These can, in turn, be converted by esterification into the methyl esters ?10 a-c. ?Reaction of N, N'-carbonyl diimidazole (Im C...

in this study, caffeic acid (ca) and its three derivatives including 3-caffeoylquinic acid (3-cqa, neochlorogenic acid), 4-caffeoylquinic acid (4-cqa, cryptochlorogenic acid), and 5-caffeoylquinic acid (5-cqa, chlorogenic acid) were identified in bupleurum chinense aerial parts using reverse-phase high-performance liquid chromatography (rp-hplc) with photodiode array (pda) detector, reference c...

one pot solvent less synthesis of amidoalkylnaphthol derivatives via reaction of aldehydes, 2-naphthol and acetamide/urea in the presence of phenylphosphinic acid is  described. this methodology provides a simple synthetic route to amidoalkylnaphthols in good to high yields.

a facile one-pot method with good yield for the synthesis of 2,4-dichloroquinoline and some related new derivatives by condensation of the appropriate primary aromatic amine with malonic acid in presence of excess phosphorus oxychloride is described.

Nicotinic acid and niacinamide are used in a variety of therapeutic application as important components of the co-factors, nicotinamide adenine dinucleotide and nicotinamide adenine dinucleotide phosphate. Decreasing the adverse effects will improve the stability and absorption of nicotinic acid. Nicotinic acid aspartic acid dipeptide and tetrapeptide were synthesized via Fmoc solid-phase synth...