37 research outputs found
N′-[1-(2,4-Dioxo-3,4-dihydro-2H-1-benzopyran-3-ylidene)ethyl]thiophene-2-carbohydrazide
Get PDFThe title compound, C16H12N2O4S, was obtained by the condensation of 3-acetyl-4-hydroxycoumarin with thien-2-ylcarbonyl hydrazide. The pyran ring adopts a 2,4-dione tautomeric form. The benzopyran ring system is almost coplanar with the thiophene ring [dihedral angle 0.9 (2)°]. The exocyclic C=C double bond has an E geometry. The molecular conformation is stabilized by an intramolecular N—H⋯O hydrogen bond. In the crystal, intermolecular N—H⋯O hydrogen bonds link the molecules into chains along the a axis
The Antioxidant Activity of New Coumarin Derivatives
Get PDFThe antioxidant activity of two synthesized coumarins namely, N-(4,7-dioxo-2- phenyl-1,3-oxazepin-3(2H,4H,7H)-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 5 and N-(4-oxo-2-phenylthiazolidin-3-yl)-2-(2-oxo-2H-chromen-4-yloxy)acetamide 6 were studied with the DPPH, hydrogen peroxide and nitric oxide radical methods and compared with the known antioxidant ascorbic acid. Compounds 5 and 6 were synthesized in a good yield from the addition reaction of maleic anhydride or mercaptoacetic acid to compound 4, namely N′-benzylidene-2-(2-oxo-2H-chromen-4-yloxy)acetohydrazide. Compound 4 was synthesized by the condensation of compound 3, namely 2-(2-oxo-2H-chromen-4-yloxy) acetohydrazide, with benzaldehyde. Compound 3, however, was synthesized from the addition of hydrazine to compound 2, namely ethyl 2-(2-oxo-2H-chromen-4-yloxy)acetate, which was synthesized from the reaction of ethyl bromoacetate with 4-hydroxycoumarin 1. Structures for the synthesized coumarins 2–6 are proposed on the basis of spectroscopic evidence
New tetrahedral boron heterobicycles:Cyclocondensation of phenylboronic acid with β-keto butanoic acid N-acyl hydrazones
No full textSynthesis of novel octahedral silicon compounds; Synthesis of Bis[3-(1-{[aryl(hydroxy)methylene]hydrazinylidene}ethyl)-6-methyl-2-oxo-2 H -pyran-4-olato- N, O, O ′]silicon(IV)
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CCDC 893600: Experimental Crystal Structure Determination
No full textRelated Article: Sotiria Karamouzi, Anna Maniadaki, Despina A. Nasiopoulou, Elvira Kotali, Antigoni Kotali, Philip A. Harris, James Raftery, John A. Joule|2013|Synthesis|45|2150|doi:10.1055/s-0033-133892
CCDC 1469499: Experimental Crystal Structure Determination
No full textRelated Article: Antigoni Kotali, Anna Maniadaki, Elvira Kotali, Philip A. Harris, Ewa Różycka-Sokołowska, Piotr Bałczewski, John A. Joule|2016|Synthesis|48|4117|doi:10.1055/s-0035-156261
CCDC 1482807: Experimental Crystal Structure Determination
No full textAn entry from the Cambridge Structural Database, the world’s repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures
CCDC 1469500: Experimental Crystal Structure Determination
No full textRelated Article: Antigoni Kotali, Anna Maniadaki, Elvira Kotali, Philip A. Harris, Ewa Różycka-Sokołowska, Piotr Bałczewski, John A. Joule|2016|Synthesis|48|4117|doi:10.1055/s-0035-156261
