Activated enol ethers derived from esters or the dinitrile of malonic acid, or from pentane-2,4-dione were treated with hydrazine hydrate. The structures of the obtained products - pyrazoles 5 - were studied with a focus on tautomerism and supramolecular structure. A reverse addition of the reagents led to the isolation of two novel products, namely bis-enehydrazines 6 with an unsymmetrical arr...

The stability constants of the complexes of Cu (II), Co (II) and Ni (II) ions with 3-(3’-nitrophenyl)4-(4"-chlorobenzoyl)-5-(2-hydroxyphenyl) pyrazole (L1), 3-(4’-chlorophenyl)-4-(4"-chlorobenzoyl)-5-(2hydroxyphenyl) pyrazole (L2), 3-(4’-methoxyphenyl)-4-benzoyl-5-(2-hydroxyphenyl) pyrazole (L3), 3(4-bromophenyl)-4-furoyl-5-(2-hydroxyphenyl) pyrazole (L4) have been determined by the pH-metric m...

Pyrazoles are an important class of five membered heterocyclic compounds; are widely found as the core structure in a large variety of compounds that possess important agrochemical and pharmaceutical activities. Pyrazoles have been the recent target of numerous methodologies, mostly due to their prevalence as scaffolds in synthesis of bioactive compounds and reactions in different media. The ai...

Novel N-arylpyrazole-containing enaminones 2a,b were synthesized as key intermediates. Reactions of 2a,b with active methylene compounds in acetic acid in the presence of ammonium acetate afforded substituted pyridine derivatives 5a-d. Enaminones 2a,b also reacted with aliphatic amines such as hydrazine hydrate and hydroxylamine hydrochloride to give bipyrazoles 8a,b and pyrazolylisoxazoles 9a,...

The relative ligand donor strengths of 10 pyrazole-derived ligands has been determined with great accuracy, making use of the interdependence between the donor strength of the co-ligand and the (13)C NMR chemical shift of the (i)Pr(2)-bimy carbene signal in trans-[PdBr(2)((i)Pr(2)-bimy)L] complexes ((i)Pr(2)-bimy = 1,3-diisopropylbenzimidazolin-2-ylidene; L = pyrazole-derived ligand). Even subt...

The structural specificity of the monocarboxylic acid transporter (MCT) for the transport of phenolic acids was investigated by measuring the inhibitory effect on the fluorescein transport in Caco-2 cell monolayers. Although most of the monohydroxylated derivatives had an inhibitory effect, the di- and tri-hydroxylated ones did not. The methoxylated derivatives were more inhibitory than the hyd...

A ruthenium complex bearing an "anti-Bredt" N-heterocyclic carbene was synthesized, characterized and evaluated as a catalyst for olefin metathesis. Good conversions were observed at room temperature for the formation of di- and tri-substituted olefins by ring-closing metathesis. It also allowed for the ring-opening metathesis polymerization of cyclooctadiene, as well as for the cross-metathesi...

In the title α-D-glucopyran-oside derivative, C(28)H(30)O(10)S(2), each heterocyclic ring adopts a chair conformation. In the tri-substituted ring, the meth-oxy and one sulfonate group occupy axial positions, whereas the second sulfonate group occupies an axial position. The phenyl group on the other ring is in an equatorial position. In the crystal, supra-molecular chains propagating along [10...