Water is a versatile solvent in many ways, and in this sense performing organic reactions in this medium is now of great interest. The one-pot reaction of ethyl acetoacetate or benzyl acetoacetate, with benzaldehydes and malononitrile to provide some novel 6-amino-4-aryl-5-cyano-2-methyl-4H-pyran-3-carboxylates has been performed over nano MgO with high performance in water as a green solvent a...

The title compound, C(10)H(7)FO(4), is an inter-mediate in the synthesis of the drug Fidarestat, (2S,4S)-2-aminoformyl-6-fluoro-spiro[chroman-4,4'-imidazolidine]-2',5'-dione. The di-hydro-pyran-one ring adopts an envelope conformation with the asymmetric C atom in the flap position. In the crystal, the mol-ecules are linked into zigzag chains along [100] by O-H⋯O hydrogen bonds and C-H⋯π inter-...

In the mol-ecule of the title compound, C(21)H(22)N(2)O(5), the indole system and the spiro-pyran ring are almost planar [maximum deviations of 0.0447 (17) and 0.0781 (17) Å, respectively]; the dihedral angle between them is 84.6 (3)°. The remaining six-membered ring adopts a twisted conformation. Intra-molecular N-H⋯O hydrogen bonds occur. In the crystal structure, intera-molecular N-H⋯O and C...

An easy, effective and eco-friendly one-pot process for the preparation of 4H-pyran compounds has been established by using a catalytic amount reduced graphene oxide functionalized with diethylenetriamine (rGO-DETA) in water under mild conditions. The catalyst was very this reaction provided desired products 1a–t good to high yields (87%–97%) short times. Moreover, rGO-DETA composite could be r...

Synthesis of 4-(N,N- dimethylamino)-3-aryl-3-butene-2-one, ethyl-5-aryl-4-oxo-4H-pyran-2-carboxylate, ethyl-5-aryl-4-pyridones-2-carboxylate and 5-aryl-3-cyano-5-methyl-2-pyridones (aryl=3-thienyl, 2-furyl) are described.

A series of 2-amino-4H-pyran-3-carbonitrile derivatives were designed and synthesized. Their antitubercular activities were evaluated against autoluminescent M. tuberculosis H37Ra and standard strain M. tuberculosis H37Rv. No obvious antitubercular activities could be observed (MIC > 10 g/mL). The results are in sharp contrast with the previously reported data.

Herein, the synthesis and crystal structure of 7-hy-droxy-3-(2-meth-oxy-phen-yl)-2-tri-fluoro-meth-yl-4H-chromen-4-one, C17H11F3O4, are reported. This isoflavone is used as a starting material in the preparation an array of potent and competitive FPR antagonists. The pyran ring significantly deviates from planarity and the dihedral angle between the benzo-pyran mean plane and that of the exocyc...

In the mol-ecule of the title compound, C(20)H(10)BrN(3)O(4)·C(3)H(7)NO, the spiro pyran ring adopts a twist conformation. The indole and coumarin ring systems are each nearly planar, and are oriented at a dihedral angle of 79.29 (3)°. In the crystal structure, inter-molecular N-H⋯O, N-H⋯N, C-H⋯O and C-H⋯N hydrogen bonds link the mol-ecules.

An operationally simple and efficient protocol for the construction of dihydrofuran derivatives has been accomplished via a sequential addition of N-chlorosuccinimide and a base to 2-amino-4H-pyran derivatives in alcohol medium. The one-pot protocol proceeding via tandem oxidative difunctionalization and ring contraction provides an entirely new strategy for the construction of the dihydrofuran...