177028-93-2Relevant articles and documents
Synthesis and X-ray structural investigations of 2-amino-7-methyl-4-(1- naphthyl)-5-oxo-4H,5H-pyrano[4,3-b]pyran-3-carbonitrile and 2-amino-4-(1- naphthyl)-5-oxo-4H,5H-pyrano[3,2-c]chromene-3-carbonitrile
Nesterov, Vladimir N.,Wiedenfeld, David,Nesterova, Svitlana V.,Daniels, Lee M.
, p. 917 - 922 (2005)
Synthesis and X-ray structural investigations have been carried out for the two title compounds C20H14N2O3 (4) and C23H14N2O3·C 2H3N (5). Compound 4 crystallizes in the monoclinic space group P21/n, with a = 7.0542(5), b = 8.822(1), c = 24.833(2) A, β = 94.30(4)°, V = 1541.0(4) A3, and Z = 4. Compound 5 crystallizes with an acetonitrile solvent molecule in the monoclinic space group P21/n, with a = 11.075(1), b = 7.854(1), c = 22.703(2) A, β = 90.67(1)°, V = 1974.5(3) A3, and Z = 4. In both molecules, the 4H-pyran ring adopts a flattened-boat conformation. The naphthalene substituent occupies a pseudo-axial position and the dihedral angle with the flat part of the pyran ring is equal to 94.6(3) in 4 and 76.8(3)° in 5. The mutual orientation of these fragments and the flatness of the heterocyclic rings lead to H...H intramolecular steric interactions: H4A...H18A 1.98 A in 4 and 2.11 A in 5. In the crystal of 4, intermolecular hydrogen bonds N-H...O and C-H...N link molecules into infinite tapes along the b axis. In the crystals of 5, intermolecular hydrogen bonds N-H...O and C-H...N link molecules into infinite layers parallel to the bc plane. In each case, the C-H...N interaction can be considered to be a weak hydrogen bond. The acetonitrile molecules link via intermolecular weak C-H...N hydrogen bonds to form infinite chains along the b axes.
One-pot synthesis of 2-amino-3-cyano-4H-pyrans and pyran-annulated heterocycles using sodium citrate as an organo-salt based catalyst in aqueous ethanol
Thongni, Aiborlang,Phanrang, Pynskhemborlang T.,Dutta, Arup,Nongkhlaw, Rishanlang
supporting information, p. 43 - 62 (2021/11/09)
Sodium citrate as a highly efficient catalyst is developed for the synthesis of functionalized 2-amino-3-cyano-4H-pyrans and pyran-annulated heterocycles. This method involves a one-pot three-component reaction of aromatic aldehydes, malononitrile and 1,3
Silica chemisorbed bis(hydrogensulphato)benzene (SiO2-BHSB) as a new, efficient, and recyclable catalyst for the synthesis of 5-oxopyrono[3,2-c]chromene scaffolds in water-based solvent
Kamble, Vinod T.,Waghmare, Amit S.,Murade, Vaishali D.,Kadam, Kailas R.
, p. 1038 - 1048 (2021/10/12)
The synthesis of silica chemisorbed bis(hydrogensulphato)benzene (SiO2-BHSB) as a new hybrid material was achieved by a sequence of three reactions. Structural features of the synthesized SiO2-BHSB were established by using analytica
A Laccase Heterogeneous Magnetic Fibrous Silica-Based Biocatalyst for Green and One-Pot Cascade Synthesis of Chromene Derivatives
Mogharabi-Manzari, Mehdi,Ghahremani, Mohammad Hossein,Sedaghat, Tabassom,Shayan, Fatemeh,Faramarzi, Mohammad Ali
, p. 1741 - 1747 (2019/02/20)
Green cascade approaches, which utilize sustainable and recyclable heterogeneous biocatalysts, can be used in the catalysis of multicomponent organic reactions to synthesize biologically important substances. Three magnetic nanoparticles, iron (II, III) oxide, cobalt ferrite, and nickel ferrite, were prepared by co-precipitation and functionalized with fibrous silica (KCC-1), and characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM). Laccase immobilized on CoFe2O4-KCC-1 was used as a heterogeneous biocatalyst for green and one-pot cascade synthesis of 2-amino-5-oxo-4-aryl-4H,5H-pyrano[3,2-c]chromene-3-carbonitriles. The reaction was performed in the presence of 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) as a synthetic redox mediator. The optimum reaction conditions were found to be as immobilized laccase (100 mg, 95 U) and TEMPO (2 mol-%) in a 100 mm sodium citrate buffer (pH 4.5), 40 °C, and incubation time 17 h. About 80 % of initial activity of the immobilized laccase was retained after 15 independent runs.
