176 research outputs found
N′-[(E)-1-Phenylethylidene]benzohydrazide
The title compound, C15H14N2O, crystallized with two independent molecules in the asymmetric unit. Both molecules are non-planar and have an E configuration with respect to the C=N bond. The dihedral angles between the two benzene rings are 11.1 (2)° in one molecule and 12.40 (19)° in the other. In the crystal structure, the molecules are linked by N—H⋯O hydrogen bonds and weak C—H⋯O interactions into infinite one-dimensional chains along [1 0 0]. The crystal structure is further stabilized by N—H⋯O hydrogen bonds, weak C—H⋯O and very weak C—H⋯π interactions
(1E,2E)-1,2-Bis(3-bromo-4-methoxybenzylidene)hydrazine
In the title compound, C16H14Br2N2O2, the dihedral angle between the mean planes of the two benzene rings is 33.4 (2)°. The hydrazine group is twisted slightly, with C—N—N—C and C—C—N—N torsion angles of 167.5 (4) and 177.2 (4)/174.2 (4)°, respectively
(E)-1-(2,4-Dinitrophenyl)-2-pentylidenehydrazine
The title compound, C11H14N4O4, is essentially planar with an r.m.s. deviation for the 19 non-H atoms of 0.152 Å. The conformation about the C=N bond is E, and the molecule has a U-shape as the butyl group folds over towards the aromatic system. An intramolecular C—H⋯N interaction occurs. The crystal packing is dominated by N—H⋯O hydrogen bonding and C—H⋯O contacts, leading to twisted zigzag supramolecular chains along the c direction. The crystal packing brings two nitro O atoms into an unusually close proximity of 2.686 (4) Å. While the nature of this interaction is not obvious, there are several precendents for such short nitro–nitro O⋯O contacts of less than 2.70 Å in the crystallographic literature
Benzyl N-{(1S)-2-hydroxy-1-[N′-(2-nitrobenzylidene)hydrazinylcarbonyl]ethyl}carbamate
The carbamate and hydrazone groups in the title compound, C18H18N4O6, are approximately orthogonal [dihedral angle = 83.3 (4)°], and the carbonyl groups are effectively anti [O=C⋯C=O torsion angle = −116.2 (7)°]. The conformation about the imine bond [1.295 (11) Å] is E. The crystal packing is dominated by O—H⋯O and N—H⋯O hydrogen bonding, which leads to two-dimensional arrays in the ab plane
Benzyl N-[(S)-2-hydroxy-1-({[(E)-2-hydroxy-4-methoxybenzylidene]hydrazinyl}carbonyl)ethyl]carbamate
The shape of the title compound, C19H21N3O6, is curved with the conformation about the imine bond [1.291 (3) Å] being E. While the hydroxy-substituted benzene ring is almost coplanar with the hydrazinyl residue [N—N—C—C = 177.31 (18)°], an observation correlated with an intramolecular O—H⋯N hydrogen bond leading to an S(6) ring, the remaining residues exhibit significant twists. The carbonyl residues are directed away from each other as are the amines. This allows for the formation of O—H⋯O and N—H⋯O hydrogen bonds in the crystal, which lead to two-dimensional supramolecular arrays in the ac plane. Additional stabilization to the layers is afforded by C—H⋯π interactions
tert-Butyl N-{(1S)-1-[(2,4-dihydroxybenzylidene)hydrazinecarbonyl]-2-hydroxyethyl}carbamate ethanol monosolvate
The molecule of the title ethanol solvate, C15H21N3O6·C2H6O, adopts a curved shape; the conformation about the imine bond [N=N = 1.287 (3) Å] is E. The amide residues occupy positions almost orthogonal to each other [dihedral angle = 85.7 (2)°]. In the crystal, a network of O—H⋯O, O—H⋯N and N—H⋯O hydrogen bonds leads to the formation of supramolecular arrays in the ab plane with the ethanol molecules lying to the periphery on either side. Disorder in the solvent ethanol molecule was evident with two positions being resolved for the C atoms [site occupancy of the major component = 0.612 (10)]
Synthesis and antibacterial activity against ralstonia solanacearum for novel hydrazone derivatives containing a pyridine moiety
<p>Abstract</p> <p>Background</p> <p><it>Ralstonia solanacearum</it>, one of the most important bacterial diseases on plants, is a devastating, soil-borne plant pathogen with a global distribution and an unusually wide host range. In order to discover new bioactive molecules and pesticides acting on tobacco bacterial wilt, we sought to combine the active structure of hydrazone and pyridine together to design and synthesize a series of novel hydrazone derivatives containing a pyridine moiety.</p> <p>Results</p> <p>A series of hydrazone derivatives containing a pyridine moiety were synthesized. Their structures were characterized by <sup>1 </sup>H-NMR, <sup>13 </sup>C-NMR, IR, and elemental analysis. The preliminary biological activity tests showed that compound 3e and 3g exhibited more than 80% activity against <it>Ralstonia solanacearum </it>at 500 mg/L, especially compound 3g displayed relatively good activity to reach 57.0% at 200 mg/L.</p> <p>Conclusion</p> <p>A practical synthetic route to hydrazone derivatives containing a pyridine moiety by the reaction of intermediates 2 with different aldehydes in ethanol at room temperature using 2-chloronicotinic acid and 2-amino-5-chloro-3-methylbenzoic acid as start materials is presented. This study suggests that the hydrazone derivatives containing a substituted pyridine ring could inhibit the growth of <it>Ralstonia solanacearum</it>.</p
The ligational behavior of a phenolic quinolyl hydrazone towards copper(II)- ions
<p>Abstract</p> <p>Background</p> <p>The heterocyclic hydrazones constitute an important class of biologically active drug molecules. The hydrazones have also been used as herbicides, insecticides, nematocides, redenticides, and plant growth regulators as well as plasticizers and stabilizers for polymers. The importance of the phenolic quinolyl hydrazones arises from incorporating the quinoline ring with the phenolic compound; 2,4-dihydroxy benzaldehyde. Quinoline ring has therapeutic and biological activities whereas, phenols have antiseptic and disinfectants activities and are used in the preparation of dyes, bakelite and drugs. The present study is planned to check the effect of the counter anions on the type and geometry of the isolated copper(II)- complexes as well as the ligational behavior of the phenolic hydrazone; 4-[(2-(4,8-dimethylquinolin-2-yl)hydrazono)methyl] benzene-1,3-diol; (H<sub>2</sub>L).</p> <p>Results</p> <p>A phenolic quinolyl hydrazone (H<sub>2</sub>L) was allowed to react with various copper(II)- salts (Cl‾, Br‾, NO<sub>3</sub>‾, ClO<sub>4</sub>‾, AcO‾, SO<sub>4</sub><sup>2-</sup>). The reactions afforded dimeric complexes (ClO<sub>4</sub>‾, AcO‾ ), a binuclear complex (NO<sub>3</sub>‾ ) and mononuclear complexes (the others; Cl‾, Br‾, SO<sub>4</sub><sup>2-</sup>). The isolated copper(II)- complexes have octahedral, square pyramid and square planar geometries. Also, they reflect the strong coordinating ability of NO<sub>3</sub>‾, Cl‾, Br‾, AcO‾ and SO<sub>4</sub><sup>2- </sup>anions. Depending on the type of the anion, the ligand showed three different modes of bonding <it>viz</it>. (NN)<sup>0 </sup>for the mononuclear complexes (<b>3, 4, 6</b>), (NO)<sup>- </sup>with O- bridging for the dimeric complexes (<b>1, 5</b>) and a mixed mode [(NN)<sup>0 </sup>+ (NO)<sup>- </sup>with O- bridging] for the binuclear nitrato- complex (<b>2</b>).</p> <p>Conclusion</p> <p>The ligational behavior of the phenolic hydrazone (H<sub>2</sub>L) is highly affected by the type of the anion. The isolated copper(II)- complexes reflect the strong coordinating power of the SO<sub>4</sub><sup>2-</sup>, AcO‾, Br‾, Cl‾ and NO<sub>3</sub>‾ anions. Also, they reflect the structural diversity (octahedral, square pyramid and square planar) depending on the type of the counter anion.</p
Sinteza kumarinskih heterocikličkih derivata s antioksidativnim djelovanjem i in vitro citotoksično djelovanje na tumorske stanice
The aim of the present work was to synthesise coumarinyl heterocycles and to elucidate the potential role of these compounds as antioxidants and cytotoxic agents against Dalton\u27s lymphoma ascites tumour cells (DLA) and Ehrlich ascites carcinoma cells (EAC). The synthesis of coumarin derivatives containing pyrazole, pyrazolone, thiazolidin-4-one, 5-carboxymethyl-4-thiazolidinone and 3-acetyl-1,3,4-oxadiazole ring is reported. 4-Methylcoumarinyl-7-oxyacetic acid hydrazide (1) reacted with arylazopropanes or hydrazono-3-oxobutyrate derivatives to form pyrazole (3a-c) and pyrazolone derivatives (5a-c). Heterocyclisation of Schiffs bases of 1 with thioglycolic acid, thiomalic acid or acetic anhydride afforded novel heterocyclic derivatives 4-thiazolidinones (7a-c), 5-carboxymethyl-4-thiazolidinones (8a-c) and oxadiazoles (9a-c), respectively. Some of the compounds showed promising results in in vitro antioxidant activity and cytotoxic activity against DLA cells and EAC cells.Cilj rada bio je sintetizirati kumarinske heterocikličke derivate i razjasniti njihovu potencijalnu ulogu kao antioksidativnih i citotoksičnih agenasa na tumorske stanice Daltonovog limfoma (DLA) i Ehrlichove tumorske stanice (EAC). U radu je opisana sinteza kumarinskih derivata s pirazolskim, pirazolonskim, tiazolidin-4-onskim, 5-karboksimetil-4-tiazolidinonskim i 3-acetil-1,3,4-oksadiazolskim prstenom. Hidrazid 4-metilkumarinil-7-oksioctene kiseline (1) dao je u reakciji s derivatima arilazopropana ili hidrazono-3-oksobutirata derivate pirazola (3a-c) i pirazolona (5a-c). Heterociklizacijom Schiffovih baza 1 s tioglikolnom kiselinom, tiojabučnom kiselinom ili anhidridom octene kiseline nastali su heterociklički derivati 4-tiazolidinoni (7a-c), 5-karboksimetil-4-tiazolidinoni (8a-c) i oksadiazoli (9a-c). Neki od spojeva pokazali su obećavajuće rezultate u in vitro testovima za antioksidativno i citostatsko djelovanje na DLA i EAC stanicama pokazali
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