The cross-linked microbeads with average diameter of 106-300 μm, [poly(EGDMA-MATrp)], were obtained by copolymerization reaction N-methacryloyl-L-(+)-tryptophan methyl ester (MATrp) ethylene glycol dimethacrylate (EGDMA) and successfully applied as a heterogeneous catalyst in conjugate addition nitromethane to substituted 2-iminochromenes aqueous media. A variety 2-amino-4-(nitromethyl)-4H-chro...

The treatment of β,γ-unsaturated α-ketoesters with phenols in the presence of trityl chloride and 4 Å molecular sieves in refluxing trifluoroacetic acid afforded 4-aryl-2H-chromenes in high yields, in which a reverse of the regiochemistry of Jørgensen-Rutjes chromane synthesis was observed. The isolation of 4H-chromene intermediates, confirmed by single-crystal X-ray analysis, indicates that th...

a series of 2-amino-4-(nitroalkyl)-4h-chromene-3-carbonitriles were synthesized by an efficient multicomponent reaction in aqueous media using dbu (1,8-diazabicyclo[5.4.0]undec-7-ene) as a catalyst at room temperature. mild condition, environment friendly procedure and excellent yields are the main advantages of this procedure. the cytotoxic activity of target compounds were evaluated against t...

In the title compound, C(16)H(9)BrO(5)·2C(3)H(7)NO, the chromene ring system is essentially planar. The two dimethyl-formamide solvent mol-ecules are linked by inter-molecular O-H⋯O hydrogen bonds to the 6-bromo-3-hydr-oxy-4-oxo-2-phenyl-4H-chromene-8-carboxylic acid molecules.

In the crystal structure of the title compound, C(15)H(9)FO(3), inversely oriented mol-ecules form inversion dimers through pairs of O-H⋯O hydrogen bonds. The benzene ring is twisted at an angle of 12.0 (1)° relative to the 4H-chromene skeleton of the mol-ecule. Adjacent 4H-chromene units are parallel in a given column or oriented at an angle of 50.0 (1)° in neighboring, inversely oriented, col...

In the title compound, C16H12O4, the substituent benzene ring and meth-oxy group are twisted relative to the 4H-chromene skeleton by 24.1 (1) and 61.3 (1)°, respectively. In the crystal, mol-ecules are connected by classical O-H⋯O and weak C-H⋯O hydrogen bonds, forming chains parallel to [201]. The 4H-chromene ring systems of adjacent mol-ecules are either parallel or inclined at an angle of 28...