نتایج جستجو برای: chromene

تعداد نتایج: 842  

2011
Michał Wera Vasyl G. Pivovarenko Artur Sikorski Tadeusz Lis Jerzy Błażejowski

In the crystal structure of the title compound, C(13)H(8)O(4), the inversely oriented mol-ecules form inversion dimers through pairs of O-H⋯O hydrogen-bonding inter-actions. An intramolecular O-H⋯O hydrogen bond occurs. In the packing of the mol-ecules, the nearly planar 2-(furan-2-yl)-4H-chromene units [dihedral angle between the chromene and furan rings = 3.8 (1)°] are either parallel or incl...

Journal: :Journal of the American Chemical Society 2012
Nilanjana Majumdar Keith A Korthals William D Wulff

A new route to the chromene ring system has been developed which involves the reaction of an α,β-unsaturated Fischer carbene complex of chromium with a propargyl ether bearing an alkenyl group on the propargylic carbon. This transformation involves a cascade of reactions that begins with a benzannulation reaction and is followed by the formation of an o-quinone methide, and finally results in t...

2013
B. S. Palakshamurthy S. Sreenivasa H. T. Srinivasa K. R. Roopashree H. C. Devarajegowda

In the title compound, C(24)H(26)O(5), the 2H-chromene ring system is essentially planar, with a maximum deviation of 0.029 (2) Å from the best-fit mean plane incorporating both rings. The dihedral angle between the 2H-chromene ring system and the benzene ring is 21.00 (1)°. In the crystal, pairs of C-H⋯O hydrogen bonds generate an R(2) (2)(8) ring pattern. These contacts are bolstered by weake...

Journal: :Chemical & pharmaceutical bulletin 1999
A Elomri S Michel M Koch E Seguin F Tillequin A Pierré G Atassi

Condensation of 2-chloro-3-nitrobenzoic acid with either 5-amino-7-methoxy-2,2-dimethyl-2H-chromene or 5-amino-2,2-dimethyl-2H-chromene afforded diphenylamines 14 and 15. Trifluoroacetic anhydride mediated cyclization gave the corresponding acridones 16 and 17, which were subsequently N-methylated and reduced to 11-aminoacronycine and 11-amino-6-demethoxyacronycine. These two amino compounds, w...

Journal: :Organic & biomolecular chemistry 2011
Marta Costa Filipe Areias Marian Castro Jose Brea María I Loza Fernanda Proença

A one-pot procedure was developed for the synthesis of novel 3-[amino(methoxy)methylene]-2-oxo-3,4-dihydro-2H-chromen-4-yl)-3-cyanoacetamides and chromeno[3,4-c]pyridine-1-carbonitriles from the reaction of 2-oxo-2H-chromene-3-carbonitriles and cyanoacetamides. These chromene derivatives were identified as new scaffolds for adenosine receptors and the hits 3a, 3c, 5a, and 5b were found.

Journal: :Organic & biomolecular chemistry 2016
Longyun Lyu Ming Yu Jin Qijie He Han Xie Zhaoxiang Bian Jun Wang

Bismuth triflate (Bi(OTf)3) is identified as an efficient catalyst for the direct addition of isocyanides to 2H-chromene acetals. The large scope of isocyanides and chromene acetals makes them suitable substrates in this catalytic system. By this synthetic strategy, a polyfunctional molecular scaffold, 2-carboxamide-2H-chromenes could be prepared efficiently in one step up to 95% yield. In addi...

Journal: :شیمی کاربردی 0
سید محمد وحدت مریم خاورپور فرج اله محمدزاده

nano tin dioxide was employed as a catalyst for efficient and facile preparation of pyran derivatives via the one-pot three component condensation reaction of various aldehydes with malononitrile and dimedone. chromene derivatives via the one-pot three component condensation reaction of various aldehyde with malononitrile and 4-hydroxycoumarin were also synthesized by this novel catalyst. the d...

Journal: :Archives of pharmacal research 2012
Loghman Firoozpour Najmeh Edraki Maryam Nakhjiri Saeed Emami Maliheh Safavi Sussan Kabudanian Ardestani Mehdi Khoshneviszadeh Abbas Shafiee Alireza Foroumadi

Chalcone and chromene motifs are synthetic or naturally occurring scaffolds with significant cytotoxic profile. Two types of novel regioisomeric chromene-chalcone hybrids, namely 1-(6-chloro or 6-methoxy-2H-chromen-3-yl)-3-phenylprop-2-en-1-one (Type A) and 3-(6-chloro or 6-methoxy-2H-chromen-3-yl)-1-phenylprop-2-en-1-one (Type B), both with different substituents on the phenyl ring attached to...

2014
M. Kayalvizhi G. Vasuki R. Raj Kumar V. Rajeswar Rao

In the title compound, C24H14Cl2N2O2S, the 2H-chromene ring system is approximately planar, with a maximum deviation of 0.025 (2) Å. The thia-zole ring is almost planar, with an r.m.s. deviation of 0.0022 Å, and makes a dihedral angle of 58.52 (7)° with the chromene ring system. The chromene ring system is inclined at angles of 58.3 (1) and 55.39 (9)° with respect to the two chloro-phenyl rings...

Journal: :Organic & biomolecular chemistry 2012
Sergey Paramonov Yury Fedorov Vladimir Lokshin Elena Tulyakova Gaston Vermeersch Stéphanie Delbaere Olga Fedorova

In this work, the interaction of protonated amino acids with a chromene bearing a fused 18-crown-6 ether moiety was studied by UV-vis and NMR spectroscopy. Initial closed forms of the chromene form monotopic 1 : 1 complexes, the ammonium group being localized inside the crown ether cavity. UV-irradiation leads to transformation of the ring-closed species into the ring-opened form. Depending on ...

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