Feng-Ling Yang

2-[(2,4-Dihydroxy­benzyl­idene)amino]-3′,6′-bis­(ethyl­amino)spiro­[isoindoline-1,9′-xanthen]-3-one

The title compound, C35H36N4O4, was prepared as a spirolactam ring formation of rhodamine B dye for comparison with a ring-opened form. The xanthene ring system is approximately planar. The r.m.s. deviation from planarity is 0.064 (6) Å for the xanthene ring. The dihedral angles formed by the spirolactam and 2,4-dihydroxybenzene rings with the xanthene ring system are 86.6 (9) and 88.0 (9)°, respectively.

2-[(5-Chloro-2-hy­droxy­benzyl­idene)amino]-3′,6′-bis­(diethyl­amino)­spiro­[isoindoline-1,9′-xanthen]-3-one

The title compound, C35H35ClN4O3, resulted from a spirolactam ring closure of rhodamine B dye. The xanthene ring system is approximately planar [r.m.s. deviation = 0.050 (9) Å for the xanthene ring]. The dihedral angles formed by the spirolactam and 5-chloro-2-hydroxybenzene rings with the xanthene ring system are 87.9 (7) and 79.1 (7)°, respectively.

Ethyl 6-[4-(dimethyl­amino)phen­yl]-4-hydr­oxy-2-oxo-4-(trifluoro­methyl)­hexa­hydro­pyrimidine-5-carboxyl­ate

The title compound, C16H20F3N3O4, was prepared by reaction of 4-(dimethylamino)benzaldehyde, ethyl 4,4,4-trifluoro-3-oxobutanoate and urea. In the title molecule, the pyrimidine ring adopts a half-chair conformation and there is an intramolecular hydrogen bond (O—H⋯O). The crystal structure is stabilized by two types intermolecular hydrogen bonds (N—H⋯O and N—H⋯N).

Ethyl 6-(4-fluoro-phen-yl)-4-hy-droxy-2-oxo-4-trifluoro-meth-yl-1,3-diazinane-5-carboxyl-ate monohydrate.

The asymmetric unit of the title compound, C14H14F4N2O4·H2O, contains two crystallographically independent organic molecules and two water molecules. The two 1,3-diazinane rings adopt a half-chair conformation and the dihedral angles between their mean planes and those of the benzene rings are 75.65 (4)° and 49.41 (3)° in the two molecules. The crystal structure is stabilized by intermolecular O—H⋯O and N—H⋯O hydrogen bonds.

5-Benzoyl-4-hydr­oxy-6-(4-nitro­phen­yl)-4-trifluoro­meth­yl-3,4,5,6-tetrahydro­pyrimidin-2(1H)-one monohydrate

The asymmetric unit of the title compound, C18H14F3N3O5·H2O, contains two independent formula units. The two heterocyclic molecules differ in the orientations of the benzoylphenyl group with respect to the tetrahydropyrimidine ring [C—C—C—C torsion angles of 64.5 (3) and 67.1 (3)°]. In both molecules the pyrimidine ring adopts a half-chair conformation. The molecules are linked into a two-dimensional network parallel to (001) by N—H⋯O and O—H⋯O hydrogen bonds.

6-Benz-yloxy-2-phenyl-pyridazin-3(2H)-one.

In the title compound, C17H14N2O2, the central pyridazine ring forms dihedral angles of 47.29 (5) and 88.54 (5)° with the benzene rings, while the dihedral angle between the benzene rings is 62.68 (6)°. In the crystal, molecules are linked by two weak C—H⋯O hydrogen bonds and three weak C—H⋯π interactions.

3-[(Furan-2-yl-methyl-idene)amino]-1-(4-methyl-phen-yl)thio-urea.

There are two independent molecules in the asymmetric unit of the title compound, C13H13N3OS, which was obtained from a condensation reaction of N-(p-tolyl)hydrazinecarbothioamide and furfural. The dihedral angles between the mean planes of the tolyl ring and the (furan-2-ylmethylene)hydrazine unit are 39.83 (8) and 48.95 (7)° in the two molecules. The molecules both exhibit an E configuration. In the crystal, intermolecular N—H⋯N and N—H⋯S hydrogen bonds connect the two independent molecules.

1-Benzyl­idene­amino-3-(4-methyl­phen­yl)thio­urea

In the title compound, C15H15N3S, the almost planar 2-benzylidenehydrazinecarbothioamide unit (r.m.s. deviation = 0.0351 Å) is aligned at a dihedral angle of 64.42 (6)° with respect to the plane of the tolyl ring. The molecule exhibits an E configuration for the azomethine linkage. In the crystal, intermolecular N—H⋯S hydrogen bonds about centers of inversion lead to the formation of dimers.

6-(Trifluoro-meth-yl)pyrimidine-2,4(1H,3H)-dione monohydrate.

The title compound, C5H3F3N2O2·H2O, was prepared by the reaction of ethyl 4,4,4-trifluoro-3-oxobutanoate with urea. In the crystal, the 6-(trifluoromethyl)pyrimidine-2,4(1H,3H)-dione and water molecules are linked by N—H⋯O and O—H⋯O hydrogen bonds. A ring dimer structure is formed by additional intermolecular N—H⋯O hydrogen bonds.

1-Benzoyl-4-(2-nitro-phen-yl)semicarbazide.

The title compound, C14H12N4O4, was prepared by the reaction of 2-nitrophenyl isocyanate with benzoylhydrazine. The dihedral angle between the rings is 71.49 (6)) Å. The molecular conformation is stabilized by an intramolecular N—H⋯O hydrogen bond, generating an S(6) ring. The crystal packing shows N—H⋯O hydrogen bonds.