6′-Bromo-1′H-spiro­[cyclo­hexane-1,2′-pyrido[2,3-d]pyrimidin]-4′(3′H)-one

The title compound, C₁₂H₁₄BrN₃O, is built up from two fused six-membered rings and one six-membered ring linked through a spiro C atom. The hydro­pyrimidine ring has an envelope conformation and the cyclo­hexane ring is in a chair conformation. In the crystal, mol­ecules are linked by N—H...O and N—H...N hydrogen bonds, forming a mol­ecular tape along the b axis.

4-[(2-Carb­oxy­eth­yl)amino]­benzoic acid monohydrate

In the title compound, C₁₀H₁₁NO₄·H₂O, the carboxyl group is twisted at a dihedral angle of 6.1 (3)° with respect to the benzene ring. In the crystal, the organic mol­ecules are linked by pairs of O—H...O hydrogen bonds involving both carboxyl groups, forming zigzag chains propagating along the b-axis direction. The water mol­ecules form [100] chains linked by O—H...O hydrogen bonds. The organic mol­ecule and water chains are cross-linked by N—H...O_water and O_water—H...O hydrogen bonds, generating (001) sheets.

3′,6′-Bis(diethyl­amino)-2-[(E)-2-(4-hy­droxy-3-meth­oxy­benzyl­idene­amino)­eth­yl]spiro­[isoindoline-1,9′-xanthen]-3-one ethanol monosolvate

In the title compound, C₃₈H₄₂N₄O₄·C₂H₆O, prepared via a spiro­lactam ring-formation reaction in a rhodamine dye, the xanthene ring system is approximately planar (r.m.s. deviation = 0.0014Å) and subtends dihedral angles of 88.10 (3) and 86.92 (4)° with the spiro­lactam (r.m.s. deviations = 0.0012 Å) and benzene rings, respectively. The crystal structure consists of chains parallel to [-101], formed via O—H...O inter­actions.

7′-Amino-1′H-spiro­[cyclo­heptane-1,2′-pyrimido[4,5-d]pyrimidin]-4′(3′H)-one

The title compound, C₁₂H₁₇N₅O, was obtained by cyclo­condensation of 2,4-diamino­pyrimidine-5-carbonitrile with cyclo­hepta­none. The tetra­hydro­pyrimidine ring has a dis­torted boat conformation and the cyclo­heptane ring adopts a chair conformation. In the crystal, molecules are linked via N—H...O and N—H...N hydrogen bonds generating a three-dimensional network.

2,2′-{[(2,2′-Dieth­oxy-1,1′-binaphthalene-6,6′-di­yl)bis­(4,1-phenyl­ene)]bis­(methan­ylyl­idene)}dimalononitrile

The title compound, C₄₄H₃₀N₄O₂, was prepared from 6,6′-dibromo-2,2′-dieth­oxy-1,1′-binaphthalene through a coupling reaction with 4-(4,4,5,5-tetra­methyl-1,3,2-dioxaborolan-2-yl)benzaldehyde followed by a Knoevenagel reaction with malononitrile. The dihedral angle between the symmetry-related naphthalene ring systems is 68.82 (8)° while the dihedral angle between the the naphthalene ring system and the adjacent benzene ring is 16.92 (7)°. Four symmetry-independent mol­ecules which are linked by inter­molecular C—H...π inter­action generate the packing motif in the crystal structure. One of the CN groups is disordered over two sets of sites in a 0.60 (2):0.40 (2) ratio.