1-Benzyl-3-methyl-3',5'-diphenyl­spiro­[quinoxaline-2(1H),2'(3'H)-1,3,4-thia­diazole]

In the title spiro compound, C₂₉H₂₄N₄S, the quinoxaline and thia­diazole ring systems share a common C atom; their mean planes are aligned at 87.0 (1)° in one mol­ecule and at 84.1 (1)° in the other independent mol­ecule. The thia­zole ring possesses two aromatic ring substituents and is roughly coplanar with these rings [the dihedral angles between the thia­diazole and phenyl rings are 10.7 (1) and 11.7 (1)° in one mol­ecule, and 16.8 (1) and 17.7 (1)° in the other]. The aromatic ring of the benzyl unit of one mol­ecule is disordered over two orientations in a 1:1 ratio.

3-Hy­droxy-4-phenyl-1-(prop-2-en-1-yl)-2,3,4,5-tetra­hydro-1H-1,5-benzodiazepin-2-one

The asymmetric unit of the title compound, C₁₈H₁₈N₂O₂, contains three independent mol­ecules. In each, the seven-membered diazepine ring adopts a boat conformation with the hy­droxy-substituted C atom at the prow and fused-ring C atoms at the stern. In the crystal, the mol­ecules are linked by O—H...O and N—H...O hydrogen bonds. The allyl group of one mol­ecule is equally disordered over two positions.

Ethyl 2-(2-amino-5-methyl-1,2,4-triazolo[1,5-a]pyrimidin-7-yl)acetate

The nine-membered fused-ring of the title compound, C₁₀H₁₃N₅O₂, is approximately planar [maximum deviation = 0.012 (1) Å]; the bond angle at the methylene C atom is 111.33 (10)°. In the crystal, the amino group forms hydrogen bonds to the N atoms of the triazole rings of adjacent mol­ecules, generating a ribbon running along the a axis.

5-Bromo-1-(prop-2-en-1-yl)-2,3-dihydro-1H-indole-2,3-dione

In the title compound, C₁₁H₈BrNO₂, the nine-membered fused-ring is nearly planar [maximum deviation = 0.022 (2) Å] and the allyl group is arched over the nine-membered fused-ring at a dihedral angle of 89.2 (1)°. Weak inter­molecular C—H...O hydrogen bonding is present in the crystal structure.

3-{2-[(3-{(E)-2-[4-(Dimethyl­amino)­phen­yl]ethen­yl}quinoxalin-2-yl)­oxy]eth­yl}-1,3-oxazolidin-2-one monohydrate

In the title compound, C₂₃H₂₄N₄O₃·H₂O, the 1,3-oxazoline ring is nearly planar [maximum deviation = 0.059 (2) Å] and its mean plane is twisted by 30.12 (8)° with respect to the quinoxaline fused-ring system; the benzene ring is nearly coplanar with the quinoxaline fused-ring system [dihedral angle = 2.52 (2)°]. The water mol­ecule of crystallization is hydrogen-bond donor to an N atom of the quinoxaline ring system as well as an O atom of the oxazolinone unit, the two hydrogen bonds generating a chain running along the c axis.

1,3-Bis[2-hy­droxy-2-(6-meth­oxy-2,2-dimethyl-3a,5,6,6a-tetra­hydro-2H-furo[2,3-d][1,3]dioxol-5-yl)eth­yl]-2,3-dihydro-1H-1,3-benzodiazol-2-one

In the title benzimidazolone, C₂₇H₃₈N₂O₁₁, which has N-bound glycosidic units, all five-membered O-heterocyclic rings adopt envelope conformations [for the outer rings, the C atom with the dimethyl groups represents the flap atom]. The two glycosidic units are related by a non-crystallographic twofold rotation axis that passes through the carbonyl portion. In the mol­ecular structure, the hy­droxy groups are hydrogen-bond donors to the carbonyl O atom. Weak inter­molecular C—H...O hydrogen bonding is present in the crystal structure.

2-Phenyl­thieno[2,3-b]quinoxaline

The title compound, C₁₆H₁₀N₂S, is almost planar (r.m.s. deviation for all non-H atoms = 0.080 Å). The dihedral angle between the three fused-ring system and the phenyl ring is 9.26 (3)°. The S atom and the opposite C atom of the thio­phene ring are mutually disordered with an occupancy ratio of 0.7706 (19):0.2294 (19).

5-Nitro-1-(prop-2-yn-1-yl)-2,3-dihydro-1H-1,3-benzodiazol-2-one

In the two independent mol­ecules of the title compound, C₁₀H₇N₃O₃, the nitro substitutent is twisted slightly with respect to the benzodiazol fused-ring system [dihedral angles = 4.9 (3) and 8.5 (1)°]. The two independent mol­ecules are disposed about a pseudo inversion center and are held together by N—H...O hydrogen bonds. The supramolecular dimer is essentially planar [dihedral angle between the fused rings = 2.0 (1)°]. Adjacent dimers are linked by acetyl­ene–nitro C—H...O inter­actions, generating a ribbon motif along (110).

1-Octyl-1H-benzimidazol-2(3H)-one

In the title compound, C₁₅H₂₂N₂O, the octyl group adopts an all-trans conformation. In the crystal, mol­ecules form centrosymmetric dimers with an R₂²(8) graph-set motif, linked by pairs of N—H...O hydrogen bonds. In addition, C—H...O contacts are observed.

1,1''-Bis(prop-2-en-1-yl)-1,1'',2,2''-tetra­hydro­dispiro­[indole-3,7'-[6,9]diaza­tricyclo­[7.3.0.0^2,6]dodecane-8',3''-indole]-2,2''-dione

The mol­ecule of the title compound, C₃₀H₃₂N₄O₂, lies on a twofold rotation axis that passes through the mid-points of the C-C bonds of the piperazine ring, which adopts a chair conformation. The pyrrolidine ring that is fused to the piperazine ring adopts an envelope conformation (in which the N atom represents the flap). The indoline fused-ring system is nearly planar (r.m.s. deviation = 0.044 Å); the two symmetry-related indoline fused-rings systems are aligned at 71.44 (3)°.

5,5''-Dibromo-1,1''-bis­(prop-2-en-1-yl)-1,1'',2,2''-tetra­hydro­dispiro­[indole-3,7'-[6,9]diaza­tricyclo­[7.3.0.0^2,6]dodecane-8',3''-indole]-2,2''-dione

In the mol­ecule of the title compound, C₃₀H₃₀Br₂N₄O₂, the piperazine ring adopts a chair conformation. The pyrrolidine rings that are fused to the piperazine ring adopt envelope conformations (in which the N atom represents the flap). The indoline fused-ring systems are nearly planar (r.m.s. deviations = 0.009 and 0.019 Å); the two fused rings are aligned at 60.63 (6)°.

1,1'-Dibenzyl-5,5''-dichloro-1,1'',2,2''-tetra­hydro­dispiro­[indole-3,7'-[6,9]diaza­tricyclo­[7.3.0.0^2,6]dodecane-8',3''-indole]-2,2''-dione

In the title compound, C₃₈H₃₄Cl₂N₄O₂, the piperazine ring adopts a chair conformation. The pyrrolidine rings that are fused to the piperazine ring adopt envelope conformations (in which the C atoms connecting the two rings represent the flap). The indoline ring systems are approximately planar (r.m.s. deviations = 0.026 and 0.034 Å) and are aligned at a dihedral angle of 54.98 (3)°.

(3R,4S)-3,4,8-Trihy­droxy-1,2,3,4-tetra­hydro­naphthalen-1-one monohydrate from Embellisia eureka

In the title hydrate, C₁₀H₁₀O₄·H₂O, the six-membered aliphatic ring that is fused to the benzene ring has a sofa shape, with the hy­droxy group in the 3-position (that represents the sofa back) of the aliphatic ring occupying a quasi-axial position. The hy­droxy group of the aromatic ring is hydrogen-bond donor to the carbonyl O atom; other O—H...O hydrogen bonds link the organic mol­ecules and the water mol­ecules into a three-dimensional network.

1-Phenyl-3H-2,3-benzodiazepin-4(5H)-one

The seven-membered ring in the title compound, C₁₅H₁₂N₂O, adopts a boat-shaped conformation (with the methyl­ene C atom as the prow and the double-bond C=N pair of atoms as the stern). In the crystal, adjacent mol­ecules are linked by an N—H...O hydrogen bond to generate helical chains running along the a axis of the ortho­rhom­bic unit cell.

1-Dodecyl-1H-benzo[d]imidazol-2(3H)-one

In the title compound, C₁₉H₃₀N₂O, the fused ring system is essentially planar, the maximum deviation from the mean plane being 0.013 (2) Å for the N atom bearing the dodecyl chain. The 1-dodecyl group is almost perpendicular to the 1H-benzo[d]imidazol-2(3H)-one plane as indicated by the dihedral angle of 82.9 (2)°between planes through the fused ring system and the first three C atoms of the chain. The C—C—C—C torsion angles (about ±179°) of the dodecyl group indicate an anti­periplanar conformation. In the crystal, inversion dimers are formed by pairs of N—H...O hydrogen bonds.

1-Allyl-1H-1,3-benzimidazol-2(3H)-one

The fused five- and six-membered rings in the title compound, C₁₀H₁₀N₂O, are approximately coplanar, with an r.m.s. deviation of 0.008 Å. The mean plane of the allyl group is roughly perpendicular to the mean plane of the 1,3-benzimidazol-2(3H)-one system, making a dihedral angle of 86.1 (2)°. In the crystal, each mol­ecule is linked to its symmetry equivalent partner by a pair of N—H...O and C—H...O hydrogen bonds.

1-Allyl-6-nitro-1H-indazole

The fused five- and six-membered rings in the title mol­ecule, C₁₀H₉N₃O₂, are essentially coplanar, the largest deviation from the mean plane being 0.012 (1) Å for the C atom linked to the nitro group. The fused-ring system makes a dihedral angle of 11.34 (6)° with the nitro group, leading to a syn-periplanar conformation. The plane through the atoms forming the allyl group is nearly perpendicular to the indazole fused-ring system, as indicated by the dihedral angle of 73.3 (5)°. In the crystal, each mol­ecule is linked to its symmetry equivalent about the center of inversion by pairs of non-classical C—H...O hydrogen bonds, forming an extended tape motif parallel to the (-12-1) plane.