نتایج جستجو برای: 4h chromene

تعداد نتایج: 7259  

Journal: :Symmetry 2015
Isaac G. Sonsona Eugenia Marqués-López Raquel P. Herrera

The structural motif that results from the fusion of a benzene ring to a heterocyclic pyran ring, known as chromene, is broadly found in nature and it has been reported to be associated with a wide range of biological activity. Moreover, asymmetric organocatalysis is a discipline in expansion that is already recognized as a well-established tool for obtaining enantiomerically enriched compounds...

2015
Yoshinobu Ishikawa

In the title compound, C10H4BrFO3, a brominated and fluorinated 3-formyl-chromone derivative, all atoms are essentially coplanar (r.m.s. deviation of 0.025 Å for the non-H atoms), with the largest deviation from the least-squares plane [0.050 (6) Å] being for a benzene-ring C atom. In the crystal, mol-ecules are linked through stacking inter-actions [centroid-centroid distance between the benze...

2017
Ligia R. Gomes John Nicolson Low Fernando Cagide Fernanda Borges

Chromone derivatives have been extensively studied recently because of to their promising biological activities. The new title chromone-thia-zole hybrid presented here, C14H10N2O3S, is a candidate as a selective ligand for adenosine receptors. The compound has been synthesized and characterized by the usual spectroscopic means (NMR and EM/IE) and its structure elucidated by X-ray crystallograph...

2013
Ahmed M. El-Agrody Ahmed M. Fouda Mohamed A. Al-Omar Abd El-Galil E. Amr Seik Weng Ng Edward R. T. Tiekink

In the title compound, C23H20BrNO4, the pyran ring has a flattened boat conformation with the O and methine C atoms lying to one side of the plane [0.160 (5) and 0.256 (6) Å, respectively] defined by the remaining atoms. Nevertheless, the 4H-benzo[h]chromene ring system approximates a plane (r.m.s. deviation = 0.116 Å) with the bromo-benzene ring almost perpendicular [dihedral angle = 83.27 (16...

2016
Yoshinobu Ishikawa

In the title compound, C10H5IO3, an iodinated 3-formyl-chromone derivative, the non-H atoms are essentially coplanar (r.m.s. deviation = 0.0344 Å), with the largest deviation from the least-squares plane [0.101 (3) Å] being found for the formyl O atom. In the crystal, mol-ecules are linked through stacking inter-actions [centroid-centroid distance between the benzene rings = 3.700 (3) Å] and C-...

2013
H. C. Devarajegowda K. Mahesh Kumar S. Seenivasa H. K. Arunkashi O. Kotresh

In the title compound, C(16)H(17)NO(4)S(2), the 2H-chromene ring system is nearly planar, with a maximum deviation of 0.070 (1) Å, and the morpholine ring adopts a chair conformation; the bond-angle sum for its N atom is 357.9°. The dihedral angle between the the 2H-chromene ring and the best plane through the morpholine ring is 89.09 (6)°. An intra-molecular C-H⋯S hydrogen bond occurs. In the ...

2014
S. Antony Inglebert Jayabal Kamalraja K. Sethusankar Gnanasambandam Vasuki

In the title compound, C18H19BrN2O4, the chromene unit is not quite planar (r.m.s. deviation = 0.199 Å), with the methyl C atoms lying 0.027 (4) and 1.929 (4) Å from the mean plane of the chromene unit. The six-membered carbocyclic ring of the chromene moiety adopts an envelope conformation, with the dimethyl-substituted C atom as the flap. The methyl-amine and nitro groups are slightly twisted...

2008
Zhi Hong Hua-Jiang Jiang Yu-Guo Zhuang Hai-Chang Guo

In the title compound, C(17)H(12)O(4), the chromene unit is approximately planar, the maximum deviation from the mean plane being 0.0166 Å. The attached phenyl ring makes a dihedral angle of 53.2 (1)° with the fused ring system. The packing of the mol-ecules in the crystal structure is governed by C-H⋯O and O-H⋯O hydrogen-bonding inter-actions.

2014
Yoshinobu Ishikawa

In the title compound, C10H5BrO3, a brominated 3-formyl-chromone derivative, all atoms are essentially coplanar (r.m.s. = 0.0631 Å for the non-H atoms), with the largest deviation from the least-squares plane [0.215 (3) Å] being for the formyl O atom. In the crystal, mol-ecules are linked into tapes through C-H⋯O hydrogen bonds and these tapes are assembled by stacking inter-actions [centroid-c...

2009
Xiao Hu Song Lei Chang-Sheng Yao

The title mol-ecule, C(22)H(16)ClNO(5), was obtained by the reaction of (E)-ethyl 3-(3-chloro-phen-yl)-2-cyano-acrylate and 2-hydroxy-naphthalene-1,4-dione catalysed by triethylamine in ethanol. In the crystal structure, the chlorobenzene ring makes a dihedral angle of 88.63 (4)° with the fused ring system. The six-membered ring formed by an intra-molecular N-H⋯O hydrogen bond is almost planar....

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