In the title compound, C(10)H(20)O(4), the dioxane ring adopts a chair conformation. The tert-butyl group occupies an equatorial position, and is staggered with respect to the O atoms of the dioxane ring. In the crystal, mol-ecules are connected by O-H⋯O hydrogen-bonds into zigzag chains of R(4) (4)(8) and R(2) (2)(12) ring motifs that run parallel to the a axis.

In the title compound, C(18)H(14)BrN(3)O(2)·H(2)O, the dihedral angle between the mean planes of the benzene ring and the quinoline ring system is 34.2 (3)°. In the crystal, the constituents are linked into chains by O-H⋯O, N-H⋯O and O-H⋯N hydrogen bonds.

In the title compound, C(13)H(9)Cl(2)N(3)O·H(2)O, the 3,4-dichloro-benzene ring is nearly coplanar with the pyridine ring, making a dihedral angle of 4.78 (8)°. Inter-molecular O-H⋯O, O-H⋯N, N-H⋯O and weak C-H⋯O hydrogen bonding is present in the crystal structure.

In the title compound, C(25)H(16)Cl(2)O(4)·C(2)H(6)O, the two 4-chloro-benzoyl groups are in syn orientations with respect to the naphthalene ring system and are approximately parallel to each other: the dihedral angle between the benzene rings is 11.43 (16)°. The conformation around each of the carbonyl C-(C=O)-C groups forms a larger angle to the plane of the naphthalene ring system than that...

In the mol-ecule of the title compound, C(16)H(12)ClF(3)N(2)O(4)S, the thia-diazine ring adopts a half-chair conformation. The dihedral angle between the benzene ring of the benzothia-diazine ring system and trifluoro-phenyl group is 15.02 (7)°. In the crystal, centrosymmetrically related mol-ecules are linked into dimers via pairs of O-H⋯O hydrogen bonds, generating R(2) (2)(8) ring motifs. Th...

In the title compound, C(28)H(23)N(3)O(4), the dihedral angle between the quinoline and indole ring systems is 29.30 (5)°. The pyrrolidine ring adopts a twist conformation. An intra-molecular O-H⋯O hydrogen bond generates an S(6) ring motif. A weak intra-molecular C3-H3⋯O3 inter-action is also observed. In the crystal, mol-ecules are linked by two sets of N-H⋯O hydrogen bonds, forming centrosym...

In the title compound, C(15)H(10)FN(5)O(3)S, an intra-molecular N-H⋯N hydrogen bond generates an S(5) ring, whereas N-H⋯O and C-H⋯S inter-actions complete S(6) ring motifs. The dihedral angle between the isatin ring system and the fluoro-benzene ring is 5.96 (6)° and the complete mol-ecule is close to planar (r.m.s. deviation for all the non-H atoms = 0.112 Å). In the crystal, mol-ecules are li...

In the title isoquinoline-dione derivative, C(16)H(16)N(2)O(3)S, the piperidine ring in the tetra-hydro-isoquinoline ring system adopts a distorted envelope conformation. The thia-zole ring is essentially planar [maximum deviation = 0.004 (1) Å] and is inclined at a dihedral angle of 31.08 (3)° with respect to the mean plane through the tetra-hydro-isoquinoline ring system. In the crystal struc...

The title compound, C(35)H(38)N(4)O(3), was prepared as a spiro-lactam ring formation of rhodamine dye for comparison with a ring-opened form. The xanthene ring system is approximately planar. The dihedral angles formed by the spiro-lactam and phenol rings with the xanthene ring system are 85.7 and 109.4°, respectively. Each of the mol-ecules in the crystal structure contains one intra-molecula...

In the title compound, C(20)H(15)N(3)O(2)·CH(3)OH, the quinazolin-one ring system is approximately planar, the dihedral angle between the pyrimidinone ring and the adjacent benzene ring being 1.73 (6)°. The pyrimidinone ring makes dihedral angles of 77.58 (6) and 29.62 (6)°, respectively, with the hy-droxy-phenyl and phenyl rings. In the crystal, the components are connected by O-H⋯O and C-H⋯O ...