Guang-Fan Han

Green Synthesis of 1,8-Dioxo-octahydroxanthene Derivatives Using Catalytic Amount of H2SO4 in Water

An green and convenient approach to the synthesis of 3,6,9-aryl-1,8-dioxo-1,2,3,4,5,6,7,8-octahydroxanthene derivatives from appropriate aromatic aldehydes and 5-aryl-1,3-cyclo-hexanedione in the presence of two drops of concentrated H2SO4 as a catalyst in water is described. This method provides several advantages such as environmental friendliness, low cost, excellent yields, and simple workup procedure.

Synthesis of Enaminones in Aqueous Media Using Catalytic Dilute HCl

Abstract A green and convenient approach to the synthesis of β-enaminones from aromatic amines and 5-substituted-1,3-cyclohexanedione in the presence of dilute hydrochloric acid (30 mmol/L) as a catalyst in solvent-free media is described. This method provides several advantages such as environmental friendliness, low cost, good yields, and simple workup procedure.

Synthesis and Crystal Structure of 7,8-Dihydroquinolino[2,3-a]acridine Derivatives

Abstract Novel 9-amino-3-substituted-1,2,3,4-acridin-1-one derivatives and 9,14-diamino-7-substituted-7,8-dihydroquinolino[2,3-a]acridine derivatives were synthesized by the condensation reaction of 5-substituted-1,3-cyclohexanedione with 2-aminobenzonitrile and substituted 2-aminobenzonitrile using p-toluenesulfonic acid, K2CO3, and Cu2Cl2 as catalysts. The structures of all compounds were characterized by elemental analysis, infrared, mass spectrometry, and 1H and 13C NMR spectra. The crystal and molecular structures of 6, 14-diamino-3,4,11,12-tetramethoxy-7-phenyl-7,8-dihydroquinolino[2,3-a]acridine 5a have been determined by single-crystal x-ray diffraction analysis. The crystal of compound 5a belongs to triclinic with space group P-1, a = 1.06168(15) nm, b = 1.16951(17) nm, c = 1.6020(2) nm, α = 71.380(3)°, β = 77.686(3)°, γ = 66.743(3)°, Z = 2, V = 1.7231(4) nm3, R 1 = 0.1060, and wR 2 = 0.2192.

2-Amino-4-(2-chloro­phen­yl)-7,7-di­methyl-5-oxo-5,6,7,8-tetra­hydro-4H-chromene-3-carbonitrile hemihydrate

The asymmetric unit of the title compound, C18H17ClN2O2·0.5H2O, contains two organic molecules and one solvent water molecule. In each organic molecule, the cyclohexene ring adopts an envelope conformation with the C atom connecting the two methyl groups on the flap; the 4H-pyran ring is nearly planar [maximum deviation = 0.113 (3) Å in one molecule and 0.089 (3) Å in the other molecule] and is approximately perpendicular to the chlorophenyl ring [dihedral angle = 86.43 (15)° in one molecule and 89.73 (15)° in the other molecule]. Intermolecular N—H⋯N, N—H⋯O, O—H⋯O and O—H⋯Cl hydrogen bonding is present in the crystal.

4-Amino-3-phenyl-1H-1,2,4-triazole-5(4H)-thione

In the title compound, C8H8N4S, the planar triazole ring forms a dihedral angle of 13.7 (2)° with the phenyl ring. The crystal structure is stabilized by intermolecular N—H⋯S hydrogen-bond interactions, linking the molecules into chains along the a axis.

Synthesis of Derivatives of Chlorin P6 Trimethyl Ester

The Vilsmeier reaction of nickel(II) chlorin P6 trimethyl ester with 3-dimethyl-aminoacrolein yielded nickel(II) chlorin P6 20-(2-formylvinyl) trimethyl ester and nickel(II) chlorin P6 3-(1-hydroxyethyl)-3-devinyl-20-(2-formylvinyl) trimethyl ester. Also, the outgrowths of nickel(II) chlorin P6 20-(2-formyl) trimethyl ester and nickel(II) chlorin P6 3-(2-formylvinyl)-3-devinyl-20-(2-formyl) trimethyl ester were obtained by Vilsmeier reaction with dimethylformamide. By treating the derivatives of nickel(II) 20-(2-formyl)-chlorin and nickel(II) 3-(2-formylvinyl)-20-(2-formyl)-chlorin with trifluoracetic acid, the removal of the central nickel(II) ion was accomplished. The derivatives of 20-(2-formyl)-chlorin and 3-(2-formylvinyl)-20-(2-formyl)-chlorin demonstrated considerable bathochromic shift of the major absorption band in the red region of the optical spectrum.

9-(4-Chloro­phen­yl)-3,6-diphenyl-1,2,3,4,5,6,7,8-octa­hydro-9H-xanthene-1,8-dione

In the title compound, C31H25ClO3, the central ring of the xanthene core shows a shallow boat conformation, while the outer six-membered rings display envelope conformations. The dihedral angle between the outer aromatic rings is 88.1 (3)° and the dihedral angles between the chlorobenzene ring and the two phenyl rings are 69.5 (2) and 69.6 (2)°.

2-(1H-Tetra­zol-5-yl)benzonitrile

The title compound, C8H5N5, was synthesized from phthalonitrile. The benzonitrile and tetrazole rings are inclined at a dihedral angle of 37.14 (11)°. In the crystal structure, intermolecular N—H⋯N hydrogen bonds link the tetrazole rings of adjacent molecules, forming chains along the a axis.

Dichloridobis(3,5-dimethyl-1H-pyrazol-4-amine-κN2)cobalt(II)

In the title compound, [CoCl2(C5H9N3)2], the CoII atom adopts a slightly distorted tetrahedral coordination geometry provided by two chloride anions and two N atoms from the organic ligands. The dihedral angle between the pyrazole rings is 85.91 (10)°. In the crystal structure, molecules are linked into a three-dimensional network by intermolecular N—H⋯N and N—H⋯Cl hydrogen-bonding interactions.