نتایج جستجو برای: chromene

تعداد نتایج: 842  

2009
Angannan Nallasivam Munirathinam Nethaji Nagarajan Vembu Buckle Jaswant Nagarajan Sulochana

The title mol-ecule, C(21)H(18)O(8), crystallizes in two crystal polymorphs, see also Nallasivam, Nethaji, Vembu & Jaswant [Acta Cryst. (2009), E65, o312-o313]. The main difference between the two polymorphs is in the conformation of the oxomethyl-acetate groups with regard to the almost planar [total puckering amplitude 0.047 (2) Å] chromene ring. In the title compound, the best planes of the ...

2015
K. Mahesh Kumar K. R. Roopashree M. Vinduvahini O. Kotresh H. C. Devarajegowda

In the title compound, C15H14BrNO3S2, the 2H-chromene ring system is nearly planar, with a maximum deviation of 0.034 (2) Å, and the morpholine ring adopts a chair conformation. The dihedral angle between best plane through the 2H-chromene ring system and the morpholine ring is 86.32 (9)°. Intra-molecular C-H⋯S hydrogen bonds are observed. In the crystal, inversion-related C-H⋯S and C-H⋯O inter...

2012
N. M. Mahabaleshwaraiah K. Mahesh Kumar O. Kotresh Waleed Fadl Ali Al-eryani H. C. Devarajegowda

In the title compound, C(17)H(19)NO(2)S(2), the 2H-chromene ring system is almost planar, with a maximum deviation of 0.044 (2) Å, and the pyrrolidine ring adopts an envelope conformation. The dihedral angle between the 2H-chromene system and the planar part of the pyrrolidine ring is 83.65 (8)°. A weak intra-molecular C-H⋯S hydrogen bond occurs. The crystal structure features C-H⋯O hydrogen bo...

2013
G. Jagadeesan K. Sethusankar D. Kathirvelan J. Haribabu B. S. R. Reddy

In the title compound C38H32N4O3, one pyrrolidine ring adopts an envelope conformation with the N atom as the flap while other pyrrolidine ring adopts an twisted conformation. The pyrrolizine ring forms dihedral angles of 79.24 (5) and 77.57 (5)° with the chromene and indole rings, respectively. The carbonyl O atoms deviate from the least-square planes through the chromene and indole rings by 0...

Journal: :Organic & biomolecular chemistry 2013
Wenjun Li Jiayao Huang Jian Wang

A new efficient enantioselective conjugate addition strategy has been disclosed to rapidly construct 2-amino-3-nitrile-chromene complexes via a multi-hydrogen-bond cooperative activation model.

Journal: :Russian Journal of General Chemistry 2022

Abstract 4-(2-Pyridylazo)resorcinol (PAR) sodium salt reacts with aromatic aldehydes and malononitrile in aqueous ethanol to form 2-amino-4-aryl-5-hydroxy-6-(2-pyridylazo)-4 H -chromene-3-carbonitriles.

2013
K. Mahesh Kumar M. Vinduvahini N. M. Mahabhaleshwaraiah O. Kotresh H. C. Devarajegowda

In the title compound, C17H19NO3S2, the maximum deviation of atoms in the 2H-chromene ring system is 0.0097 (14) Å and the piperidine ring adopts a chair conformation. The dihedral angle between the 2H-chromene ring and the piperidine ring (all atoms) is 87.59 (8)°. In the crystal, inversion dimers linked by pairs of C-H⋯O inter-actions generate R 2 (2)(22) loops. Further C-H⋯O hydrogen bonds l...

Journal: :Advanced Engineering Materials 2022

In recent years, dual‐cure chemistry has been exploited to realize interpenetrating networks (IPNs) that provide enhanced thermo‐mechanical properties. this contribution, photoinduced curing of (meth)acrylates is used build the desired 3D structure, whereas thermally triggered polymerization reaction 2H‐chromene functionalized building blocks utilized create IPN. This strategy combines advantag...

1-Methyl-1H-imidazol-3-ium 2,3,4,5,6-pentafluorophenolate [mim]C6F5O as a novel nano ionic liquid was designed, synthesized and characterized by using various techniques such as Fourier transform spectroscopy infrared (FT-IR), nuclear magnetic resonance (NMR), x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), ener...

2017
Tarek H. Afifi Rawda M. Okasha Hany E.A. Ahmed Janez Ilaš Tarek Saleh Alaa S. Abd-El-Aziz

The design of novel materials with significant biological properties is a main target in drug design research. Chromene compounds represent an interesting medicinal scaffold in drug replacement systems. This report illustrates a successful synthesis and characterization of two novel series of chromene compounds using multi-component reactions. The synthesis of the first example of azo chromopho...

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