Silvia Cruz

SYNTHESIS OF 5-CYANO-4,7-DIHYDROPYRAZOLO[3,4-b]PYRIDIN-4-ONES AND 5-CYANOPYRAZOLO[3,4-b|PYRIDIN-4-ONES IN ONE-STEP BY THE REACTION OF 5-AMINO PYRAZOLONE WITH BENZ ALDEHYDE AND BENZOYLACETONITRILE IN ETHANOL AND BY MICROWAVE RADIATION IN DRY MEDIA

The titled compounds 4 and 5 have been prepared in one-step reaction from 5aminopyrazolone 1, the corresponding 4-substituted benzaldehyde 2 and benzoylacetonitrile 3 in very good yields. Compounds 5 also were obtained by microwave irradiation of compounds 1, 2 and 3 in solvent-free conditions, the results obtained over that conditions showed a considerable increase in the reaction rate with better yields. The structure of the final compounds was determined on the basis of nmr measurements.

Solvent-Free Synthesis of Fused Pyrazolo[1,5-a]pyrimidines by Reaction of 5-Amino-1H-pyrazoles and β -Triketones

The solvent-free reaction between 5-amino-1H-pyrazoles and  -triketones (2-acetyldimedone and 2- acetylindandione) leads to the formation of new fused pyrazolo(1,5-a)pyrimidines in good yields. A possible mechanistic route is postulated on the basis of the isolation of the cyclization intermediate. The structures and regiospecificity of the reaction were determined on the basis of nmr measurements and X-ray diffraction.

SYNTHESIS INDUCED BY MICROWAVE IRRADIATIO AND IN VITRO ANTIFUNGAL EVALUATION OF NEW DIHYDROPYRAZOLO[3,4-b] [1,4]DIAZEPINES

New 2and 4-methylenedioxyphenyl-8-phenyl-2,3-dihydropyrazolo[3,4-b]diazepines 3 were obtained from the reaction of 4,5-diamino-3-methyl-l-phenylpyrazole 1 with one equivalent of the methylenedioxychalcones 2 in both absolute ethanol and under solvent-free conditions microwave irradiation. The structures of diazepines 3 were determined by detailed nmr measurements. These compounds does not showed any antifungal in vitro activity up to 250 μg/ml.

4-Amino-5-(2-hydroxy-4,4-di­methyl-6-oxo­cyclo­hexenyl­methyl)-1-methyl-2-(methyl­sulfanyl)­pyrimidin-6(1H)-one: hydrogen-bonded chains are π-stacked in pairs

Molecules of the title compound, C15H21N3O3S, have a markedly polarized electronic structure; the carbocyclic ring adopts an envelope conformation and the overall molecular conformation appears to be controlled by two intramolecular hydrogen bonds, one each of the O-H...O and N-H...O types. The molecules are linked into C(6) chains by an intermolecular N-H...O hydrogen bond, and pairs of these hydrogen-bonded chains are linked by a pi-pi stacking interaction.

2,2'-Methylenebis(3-hydroxy-5,5-dimethylcyclohex-2-en-1-one)

The title compound, C(17)H(24)O(4), crystallizes with two independent molecules, both lying across twofold rotation axes in space group Pccn, in a unit cell whose dimensions closely mimic those of a tetragonal cell. Each molecule contains paired O-H.O hydrogen bonds [H.O = 1.81 and 1.83 A, O.O = 2.640 (2) and 2.642 (2) A, and O-H.O = 168 and 162 degrees ].

Síntesis de Piridazin-3(2H)-onas asistida por Microondas en Condiciones Libre de Disolvente

espanolSe describe la sintesis de una serie de piridazin-3(2H) onas y cinolin-3,5-diona a traves de la reaccion entre acetofenonas p-sustituidas o dimedona con acido glioxilico e hidrato de hidracina bajo irradiacion con microondas y en condiciones libre de disolvente. Las piridazinonas son sistemas heterociclicos nitrogenados de procedencia sintetica que han sido estudiados sistematicamente debido a su promisoria actividad biologica y farmacologica. La elucidacion estructural de los productos de realizo mediante analisis de RMN 1H, 13C, experimentos bidimensionales de HSQC, HMBC y espectrometria de masas. La metodologia propuesta produce buenos rendimientos en tiempos cortos de reaccion. Esto es de especial interes desde el punto de vista ambiental. EnglishThe synthesis of a series of pyridazin-3(2H)-ones and cinnolin-3,5-dione in the reaction of acetophenones p-substituted or dimedone with glyoxilic acid and hydrazine hydrate under microwave irradiation and solvent-free conditions is described. 5yridazinones are nitrogenated heterocyclic compound synthetically produced which have been systematically studied due to their promising biological and pharmacological activity. The structure of the products is based on detailed NMR analysis of experiments such as 1H, 13C, HSQC, HMBC and mass spectrometry. This methodology leads to good yields in short reaction times. This is of especial interest from the environmental point of view.

9-Benzoyl-3,3,6,6-tetramethyl-1,2,3,4,5,6,7,8-octahydroxanthene-1,8-dione: molecular conformation and supramolecular aggregation in xanthenediones.

In the title compound, C(24)H(26)O(4), (I), the central ring of the fused tricyclic ring system adopts a shallow boat conformation, while the two outer rings adopt envelope conformations. The molecules are linked into C(9) chains by a single C-H...O hydrogen bond. The significance of this study lies in its comparison of the conformation and supramolecular aggregation of (I) with those of related compounds in the published literature.

3-[5-(4-Bromo­phenyl)-1H-pyrazol-3-ylamino]-5,5-dimethyl­cyclo­hex-2-en-1-one–(Z)-3-(4-bromo­phenyl)-3-chloro­acrylonitrile (2/1): a stoichiometric cocrystal of a reaction product with one of its early precursors

The title compound, 2C17H18BrN3O.C9H5BrClN, was crystallized from the reaction between 5,5-dimethylcyclohexane-1,3-dione, triethyl orthoformate and 5-amino-3-(4-bromophenyl)pyrazole, which had itself been prepared from the reaction between (Z)-3-(4-bromophenyl)-3-chloroacrylonitrile and hydrazine. The compound is a stoichiometric 2:1 cocrystal of the reaction product 3-[5-(4-bromophenyl)-1H-pyrazol-3-ylamino]-5,5-dimethylcyclohex-2-en-1-one and the early reactant (Z)-3-(4-bromophenyl)-3-chloroacrylonitrile. The two independent molecules of cyclohex-2-en-1-one are linked by N-H...N and N-H...O hydrogen bonds into complex bilayers and the molecules of acrylonitrile are trapped within large cavities in the substructure formed by the cyclohex-2-en-1-one molecules.