3-(2-Methyl-phen-yl)-3a,4-dihydro-3H-chromeno[4,3-c]isoxazole-3a-carbo-nitrile

In the title compound, C(18)H(14)N(2)O(2), the pyran ring of the chromeno ring system has a half-chair conformation, and the dihedral angle between its mean plane and the benzene ring is 5.3 (2)°. The isoxazole ring forms a dihedral angle of 74.6 (2)° with the attached benzene ring and is inclined to the mean plane of the chromeno ring system by 15.06 (19)°. In the crystal, there are no significant inter-molecular inter-actions.

14-Eth-oxy-4,6-dimethyl-9-phenyl-8,12-dioxa-4,6-diaza-tetra-cyclo-[8.8.0.0(2,7).0(13,18)]octa-deca-2(7),13,15,17-tetra-ene-3,5,11-trione

In the title compound, C₂₃H₂₀N₂O₆, the fused pyrone and pyran rings each adopt a sofa conformation. The dihedral angle between the mean planes of the pyran and phenyl rings is 61.9 (1)°. In the crystal, mol­ecules are linked by two pairs of C—H⋯O hydrogen bonds, forming dimers. These dimers are linked via a third C—H⋯O hydrogen bond, forming a two-dimensional network parallel to (10-2).

Methyl (E)-2-cyano-3-(6-nitro-1,3-benzodioxol-5-yl)acrylate

In the title compound, C₁₂H₈N₂O₆, the 1,3-benzodioxole ring system is essentially planar [maximum deviation = 0.036 (2) Å] and the nitro group is oriented at a dihedral angle of 15.4 (1)° with respect to its mean plane. In the crystal, moleucles are linked into C(8) [101] chains by C—H⋯O hydrogen bonds, and weak aromatic π–π stacking [centroid–centroid distance = 3.887 (1) Å] also occurs.

(E)-3-(1,3-Benzodioxol-5-yl)-2-{[N-(2-formylphenyl)-4-methylbenzenesulfon-amido]methyl}prop-2-enenitrile

In the title compound, C(25)H(20)N(2)O(5)S, the benzodioxole ring system is essentially planar [maximum deviation = 0.021 (2) Å] and forms dihedral angles of 85.2 (1) and 74.2 (1)°, respectively, with the formyl benzene and sulfonyl-bound benzene rings. In the crystal, C-H⋯O hydrogen bonds generate C(8) chains along [100] and R(3) (3)(19) ring motifs. In addition, a weak π-π inter-action [centroid-centroid distance = 3.937 (3) Å] is also observed.

(Z)-3-Benzyl-1,5-benzothia-zepin-4(5H)-one

In the crystal structure of the title compound, C(16)H(13)NOS, mol-ecules are linked into cyclic centrosymmetric R(2) (2)(8) dimers via pairs of N-H⋯O hydrogen bonds. The seven-membered ring adopts a boat conformation.

2-(2-Nitrophenyl)-1,3-benzothiazole

In the title compound, C₁₃H₈N₂O₂S, the essentially planar benzothia­zole system [maximum deviation = −0.012 (1) Å for the S atom] is oriented at a dihedral angle of 48.3 (1)° with respect to the benzene ring. The nitro group is substanti­ally twisted from the plane of its attached benzene ring [dihedral angle = 52.0 (1)°]. The crystal packing features C—H⋯O hydrogen bonds, which generate C(6) helical chains propagating along [010]. Weak C—H⋯π inter­actions also occur in the crystal.

2-[Hy-droxy(2-meth-oxy-phenyl)methyl]acrylonitrile

In the title compound, C₁₁H₁₁NO₂, the mean planes formed by the benzene ring and the C and N atoms of the acryl group are almost orthogonal to each other, with a dihedral angle of 85.7 (1)°. During the structure analysis, it was observed that the unit cell contains large accessible voids, with a volume of 186.9 ų, which may host disordered solvent mol­ecules. This affects the diffraction pattern, mostly at low scattering angles. Density identified in these solvent-accessible areas was calculated and corrected for using the SQUEEZE routine in PLATON [Spek (2009 ▶), Acta Cryst. D65, 148–155]. Despite the presence of the hy­droxy group in the mol­ecule, no classical or nonclassical hydrogen bonds are observed in the structure. This may reflect the fact that the O—H group points towards the solvent-accessible void.

2,2′-Diisopropoxy-5,5′-methylenedibenzaldehyde

Mol­ecules of the title compound, C₂₁H₂₄O₄, are located on a twofold rotation axis running through the central methyl­ene C atom. The aldehyde group is coplanar with the benzene ring [C—C—C—O = 175.7 (4) °].

(2E,2′E)-Dimethyl 2,2′-[(phenylazanediyl)bis(methylene)]bis(3-phenylacrylate)

The C=C double bonds in the title compound, C₂₈H₂₇NO₄, adopt an E conformation. In the crystal, pairs of C—H⋯O hydrogen bonds link the mol­ecules into inversion dimers.

(E)-Methyl 2-[(1,3-dioxoisoindolin-2-yl)methyl]-3-phenylacrylate

In the title compound, C₁₉H₁₅NO₄, the isoindole ring system is essentially planar [maximum deviation = 0.011 (1) Å] and is oriented at a dihedral angle of 75.7 (1)° with respect to the phenyl ring. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯O hydrogen bond. The crystal packing is stabilized by C—H⋯O hydrogen bonds, which generate zigzag chains along the a axis. The crystal packing is further stabilized by a C—H⋯π inter­action.

(Z)-3-(2-Meth-oxy-benz-yl)-1,5-benzo-thia-zepin-4(5H)-one

In the title compound, C₁₇H₁₅NO₂S, the seven-membered thia­zepine ring adopts a distorted twist-boat conformation. The dihedral angle between the mean planes of the benzothia­zepin ring system and the attached benzene ring is 47.7 (1)°. In the crystal, pairs of N—H⋯O hydrogen bonds link inversion-related mol­ecules into dimers, generating R₂²(8) ring motifs. These dimers are further connected into a chain along the a axis by C—H⋯O hydrogen bonds, resulting in R₂²(14) ring motifs. The crystal packing also features C—H⋯π inter­actions.

(Z)-3-(4-Chloro-benz-yl)-1,5-benzothia-zepin-4(5H)-one

In the title compound, C(16)H(12)ClNOS, the seven-membered thia-zepine ring adopts a distorted twisted boat conformation. The dihedral angle between the least-squares planes of the 1,5-benzothia-zepine ring system and the benzene ring is 50.2 (1)°. In the crystal, pairs of N-H⋯O hydrogen bonds link centrosymmetrically related mol-ecules into dimers, generating R(2) (2)(8) ring motifs. The crystal packing is further stabilized by π-π inter-actions [centroid-centroid distance = 3.763 (2) Å].

2-Formyl-6-meth-oxy-phenyl cinnamate

In the title compound, C(17)H(14)O(4), the C=C bond adopts an E conformation and the dihedral angle between the benzene rings is 73.9 (1)°. The crystal packing features C-H⋯O hydrogen bonds, which generate C(4) chains propagating along the b-axis direction. Weak aromatic π-π stacking inter-actions [centroid-centroid distance = 3.703 (1) Å] are also observed.

(Z)-3-(2-Chloro-benz-yl)-1,5-benzothia-zepin-4(5H)-one

In the crystal structure of the title compound, C₁₆H₁₂ClNOS, the mol­ecules are linked into centrosymmetric R₂²(8) dimers via pairs of N—H⋯O hydrogen bonds. The seven-membered ring adopts a boat conformation.

rac-Methyl 3-(2-meth-oxy-phen-yl)-1-phenyl-3,3a,4,9b-tetra-hydro-1H-chromeno[4,3-c]isoxazole-3a-carboxyl-ate

The title compound, C₂₅H₂₃NO₅, comprising two stereogenic carbon atoms of the same configuration, crystallizes in a centrosymmetric space group as a racemate. The six-membered pyran ring and the five-membered isoxazole ring adopt sofa and twisted conformations, respectively. The dihedral angle between the benzene ring and the mean plane through the near coplanar atoms of the pyran ring is 10.73 (7)°. The crystal structure features C—H⋯O hydrogen bonds.

Methyl (E)-2-({2-[(E)-(hy-droxy-imino)-meth-yl]phen-oxy}meth-yl)-3-(4-methyl-phen-yl)acrylate

In the title compound, C(19)H(19)NO(4), the dihedral angle between the mean planes through the benzene rings is 82.18 (7)°. The C=N double bond is trans-configured. The mol-ecules are linked into centrosymmetric dimers via pairs of O-H⋯N hydrogen bonds with the motif R(2) (2)(6). The crystal packing also features C-H⋯O inter-actions. The methyl group attached to one of the aromatic rings is disordered over two almost equally occupied positions [occpancy ratio = 0.51 (4):0.49 (4)].

1-Methyl-3-(2-methyl-phen-yl)-3a-nitro-1,2,3,3a,4,9b-hexa-hydro-chromeno[4,3-b]pyrrole

The asymmetric unit of the title compound, C(19)H(20)N(2)O(3), contains two independent mol-ecules in both of which the pyrrolidine ring adopts an envelope conformation, but with a C atom as the flap in one mol-ecule and the N atom in the other. The pyran ring adopts a half-chair conformation in both mol-ecules. In the crystal, mol-ecules are linked via C-H⋯O hydrogen bonds and C-H⋯π inter-actions.

Methyl (E)-2-[(2-nitro-phen-oxy)meth-yl]-3-phenyl-acrylate

The title compound, C₁₇H₁₅NO₅, adopts an E conformation with respect to the C=C double bond of the phenyl­acrylate unit. The phenyl ring and methyl acrylate group of the phenyl­acrylate unit are disordered over two sets of sites with site-occupancy ratios of 0.705 (5):0.295 (5) and 0.683 (3):0.317 (3), respectively. The mean plane through the benzene ring of the phenyl acrylate makes dihedral angles of 88.4 (8) (major component) and 86.7 (8)° (minor component) with the nitro­phen­oxy ring; the dihedral angle between the two components is 3.64 (6)°. Intra­molecular C—H⋯O interactions stabilise the molecular structure. In the crystal, C—H⋯O inter­actions result in a chain of mol­ecules running along the b axis.

rac-6-Ethoxy-3,3a,4,9b-tetrahydro-1,3-diphenyl-1H-chromeno[4,3-c]isoxazole-3a-carbonitrile

The title compound, C₂₅H₂₂N₂O₃, with three stereogenic centres, crystallizes in a centrosymmetric space group as a racemate. The pyran ring adopts a sofa conformation and the five-membered isoxazole ring exhibits an envelope conformation. The dihedral angle between the benzene ring and the mean plane through the near coplanar atoms of the pyran ring is 10.54 (9)°. In the crystal, no significant intermolecular interactions are observed.

Methyl (2E)-2-({2-[(2E)-2-benzylidene-3-methoxy-3-oxopropyl]-1,3-dioxoindan-2-yl}methyl)-3-phenylprop-2-enoate

In the title compound, C₃₁H₂₆O₆, the five-membered ring of the indane unit adopts a slight envelope conformation with the flap atom displaced by 1.38 (14) Å. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯O hydrogen bond, which generates an S(9) ring motif. In the crystal, pairs of C—H⋯O hydrogen bonds link centrosymmetrically related mol­ecules into dimers, generating R₂²(22) ring motifs. The crystal packing is further stabilized by C—H⋯π inter­actions.

(E)-Methyl 2-({2-eth-oxy-6-[(E)-(hy-droxy-imino)-meth-yl]phen-oxy}meth-yl)-3-phenyl-acrylate

In the title compound, C₂₀H₂₁NO₅, the dihedral angle between the mean planes through the two rings is 47.1 (8)°. The enoate group assumes an extended conformation. The hy­droxy­ethanimine group is essentially coplanar with the benzene ring, the largest deviation from the mean plane being 0.061 (1) Å for the O atom. In the crystal, mol­ecules are linked into cyclic centrosymmetric dimers with an R₂²(6) motif via pairs of O—H⋯N hydrogen bonds. Inter­molecular C—H⋯O hydrogen bonds form a C(8) chain along the b axis. The crystal packing is further stabilized by C—H⋯π inter­actions.

(E)-Methyl 3-(3,4-dimeth-oxy-phen-yl)-2-[(1,3-dioxoisoindolin-2-yl)meth-yl]acrylate

In the title compound, C(21)H(19)NO(6), the isoindole ring system is essentially planar [maximum deviation = 0.019 (2) Å for the N atom] and is oriented at a dihedral angle of 51.3 (1)° with respect to the benzene ring. The two meth-oxy groups are almost coplanar with the attached benzene ring [C-O-C-C = 3.7 (4) and 4.3 (4)°]. The mol-ecular conformation is stabilized by an intra-molecular C-H⋯O hydrogen bond, which generates an S(9) ring motif. In the crystal, mol-ecules are linked through bifurcated C-H⋯(O,O) hydrogen bonds having R(1) (2)(5) ring motifs, forming chains along the b-axis direction. The crystal packing is further stabilzed by π-π inter-actions [centriod-centroid distance = 3.463 (1) Å].

(E)-3-(2-Chlorophenyl)-2-[(2-formylphenoxy)methyl]prop-2-enenitrile

In the title compound, C17H12ClNO2, the dihedral angle between the two benzene rings is 42.9 (1)°. There are no sgnificant intermolecular interactions.

(2Z)-2-{[N-(2-Formylphenyl)-4-methylbenzenesulfonamido]methyl}-3-(4-methylphenyl)prop-2-enenitrile

In the title compound, C₂₅H₂₂N₂O₃S, the sulfonyl-bound benzene ring forms dihedral angles of 36.8 (2) and 81.4 (2)°, respectively, with the formyl­benzene and methyl­benzene rings. The mol­ecular conformation is stabilized by an intra­molecular C—H⋯O hydrogen bond, which generates an S(5) ring motif. The crystal packing is stabilized by C—H⋯O hydrogen bonds, which generate C(11) chains along the b axis. The crystal packing is further stabilized by π–π inter­actions [centroid–centroid distance = 3.927 (2) Å].

N-(2-Formyl-phen-yl)-4-toluene-sulfonamide: a second monoclinic polymorph

The title compound, C₁₄H₁₃NO₃S, (I), is a second monoclinic polymorph. The original polymorph, (II), was reported by Mahía et al. [Acta Cryst. (1999), C55, 2158–2160]. Polymorph (II) crystalllized in the space group P2₁/c (Z = 4), whereas the title polymorph (I) occurs in the space group P2₁/n (Z = 4). The dihedral angle between the two aromatic rings is 75.9 (1)° in (I) compared to 81.9 (1)° for (II). In both polymorphs, two S(6) rings are generated by intra­molecular N—H⋯O and C—H⋯O hydrogen bonds, resulting in similar mol­ecular geometries. However, the two polymorphs differ concerning their crystal packing. In (I), mol­ecules are linked into C(8) zigzag chains along the b axis by C—H⋯O hydrogen bonds, whereas in (II) mol­ecules are linked by C—H⋯O hydrogen bonds, forming C(7) chains along the b axis. The title polymorph is further stabilized by inter­molecular C—H⋯π and π–π inter­actions [centroid–centroid distance = 3.814 (1) Å]. These inter­actions are not evident in polymorph (II).