The title molecule, C17H19NO5, was prepared by a Hantzsch dihydropyridine synthesis from 4-hydroxybenzaldehyde, methyl acetoacetate and NH4HCO3. In the molecular structure of the title compound, the dihydropyridine ring adopts a flattened boat conformation and the plane of the base of the boat forms a dihedral angle of 80.8 (2)° with the aromatic six-membered ring. The packing is stabilized by strong intermolecular N—H⋯Ocarbonyl, Ohydroxy—H⋯Ocarbonyl and weak intramolecular C—H⋯O hydrogen bonds.
In the title hydrate, C16H15BrO2SSe·H2O, the sulfinyl O atom lies on the opposite side of the molecule to the Se and carbonyl O atoms. The benzene rings form a dihedral angle of 51.66 (17)° and are splayed with respect to each other. The observed conformation allows the water molecules to bridge sulfinyl O atoms via O—H⋯O hydrogen bonds, generating a linear supramolecular chain along the b axis; the chain is further stabilized by C—H⋯O contacts. The chains are held in place in the crystal structure by C⋯H⋯π and C—Br⋯π interactions.
In the title hydrate, C18H20BrO4P·H2O, a staggered conformation is found when the organic molecule is viewed down the central P—C bond, with the oxo and hydroxyl groups being diagonally opposite; each of the central P and C atoms has an S-configuration. The crystal structure features supramolecular double chains along the b axis mediated by Ohydroxyl–H⋯Ooxo, Owater–H⋯Ooxo, and Owater–H⋯Owater hydrogen bonds.
In the title compound, C21H21BrClNO4, the dihydropyridine ring adopts a flattened boat conformation. The 3-bromo-5-chloro-2-hydroxyphenyl ring forms a dihedral angles of 84.44 (7)° with the dihydropyridine mean plane. The molecular conformation is stabilized by an intramolecular O—H⋯O hydrogen bond, with an S(8) ring motif. In the crystal, O—H⋯O and C—H⋯O hydrogen bonds link the molecules, forming a three-dimensional network.
In the asymmetric unit of the title nicotinonitrile derivative, C23H21BrN2O4, there are two non-planar independent molecules. The central pyridine ring makes dihedral angles of 9.05 (7) and 77.06 (7)°, respectively, with the 4-bromophenyl and 2,4,6-trimethoxyphenyl rings in one molecule, whereas the corresponding values are 5.96 (7) and 82.37 (7)° in the other. All the three methoxy groups are essentially in the plane of the attached benzene ring [C—O—C—C angles = 2.99 (19), 4.8 (2) and −6.2 (2)° in one molecule, and 2.69 (18), 176.73 (15) and 1.3 (2)° in the other]. The ethoxy group is slightly twisted in one molecule [C—C—O—C = 173.84 (12)°], whereas it is coplanar with the pyridine ring in the other [C—C—O—C = −177.23 (13)°]. Weak intramolecular C—H⋯N interactions generate S(5) ring motifs. In the crystal structure, the molecules are linked by weak intermolecular C—H⋯N and C—H⋯O interactions into a supramolecular three-dimensional network in such a way that the nicotinonitrile units of neighboring molecules are stacked in an antiparallel manner along the c axis. The crystal is further stabilized by C—H⋯π interactions.
Reaction of 4-methyl benzyl chloride with barbituric acid gave 5,5-bis(4-methylbenzyl)pyrimidine-2,4,6(1H,3H,5H)-trione, which crystallized with two molecules in its asymmetric unit along with two solvent water molecules. A hydrogen-bonded sheet is formed by a combination of N—H⋯O and Owater—H⋯O hydrogen bonds, which are further interconnected by C—H⋯πaryl interactions, leading to a three-dimensional supramolecular architecture.
The asymmetric unit of the title compound, C20H20N2O3·H2O, contains two independent molecules (A and B), with similar conformations and two independent water molecules. In the crystal, N—H⋯O and Owater—H⋯O hydrogen bonds link all moieties into two crystallographically independent kinds of sheets parallel to the ac plane. These independent sheets, each containing either A or B molecules, are further alternately stacked along the b axis and interconnected via C—H⋯πaryl interactions.
crystal structure; hydrogen-bonded sheets; pyrimidine; C—H⋯π interactions; Knoevenagel condensation; three-dimensional structure
Crystal structure of ethyl 2-[9-(5-bromo-2-hydroxyphenyl)-1,8-dioxo-1,2,3,4,5,6,7,8,9,10-decahydroacridin-10-yl]acetate
In the title compound, C23H24BrNO5, the central 1,4-dihydropyridine ring of the 1,2,3,4,5,6,7,8,9,10-decahydroacridine ring system adopts a half-chair conformation. The two cyclohexene rings fused to the central ring both have a twisted-boat conformation. The mean planes of the bromohydroxyphenyl ring and the major and minor components of the disordered ethyl aminoacetate moiety make dihedral angles of 78.99 (12), 85.9 (2) and 88.3 (9)°, respectively, with the 1,4-dihydropyridine ring. The terminal ethyl group of the ethyl aminoacetate moiety is disordered over two sets of sites with refined occupancies of 0.768 (17) and 0.232 (17). The molecular conformation is stabilized by an intramolecular O—H⋯O hydrogen bond, forming an S(8) ring motif. In the crystal, C—H⋯O hydrogen bonds connect the molecules into layers parallel to (001), enclosing R
2(7) ring motifs.
crystal structure; acridines; hydroacridinones; hydrogen bonding
In three quinolone compounds, the 1,4-dihydropyridine (1,4-DHP) rings adopt flat-boat conformations which are bisected by the plane of the pseudo-axial brominated aryl ring. The cyclohexanone rings adopt an envelope conformation. In all three compounds, intermolecular N—H⋯O hydrogen bonds link the molecules into extended chains. Intermolecular halogen bonding between Br and the ester carbonyl O atom is observed in two of the compounds.
Three quinolone compounds were synthesized and crystallized in an effort to study the structure–activity relationship of these calcium-channel antagonists. In all three quinolones, viz. ethyl 4-(4-bromophenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate, (I), ethyl 4-(3-bromophenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate, (II), and ethyl 4-(2-bromophenyl)-2,7,7-trimethyl-5-oxo-1,4,5,6,7,8-hexahydroquinoline-3-carboxylate, (III), all C21H24BrNO3, common structural features such as a flat boat conformation of the 1,4-dihydropyridine (1,4-DHP) ring, an envelope conformation of the fused cyclohexanone ring and a bromophenyl ring at the pseudo-axial position and orthogonal to the 1,4-DHP ring are retained. However, due to the different packing interactions in each compound, halogen bonds are observed in (I) and (III). Compound (III) crystallizes with two molecules in the asymmetric unit. All of the prepared derivatives satisfy the basic structural requirements to possess moderate activity as calcium-channel antagonists.
crystal structure; structure–activity relationships; calcium-channel antagonists; quinolone compounds; halogen bonding; 1,4-dihydropyridine rings; hydrogen bonding; bromine scanning
The conformation and tautomeric structure of (Z)-4-[5-(2,6-difluorobenzyl)-1-(2-fluorobenzyl)-2-oxo-1,2-dihydropyridin-3-yl]-4-hydroxy-2-oxo-N-(2-oxopyrrolidin-1-yl)but-3-enamide, C27H22F3N3O5, in the solid state has been resolved by single-crystal X-ray crystallography. The electron distribution in the molecule was evaluated by refinements with invarioms, aspherical scattering factors by the method of Dittrich et al. [Acta Cryst. (2005), A61, 314–320] that are based on the Hansen–Coppens multipole model [Hansen & Coppens (1978 ▶). Acta Cryst. A34, 909–921]. The β-diketo portion of the molecule exists in the enol form. The enol –OH hydrogen forms a strong asymmetric hydrogen bond with the carbonyl O atom on the β-C atom of the chain. Weak intramolecular hydrogen bonds exist between the weakly acidic α-CH hydrogen of the keto–enol group and the pyridinone carbonyl O atom, and also between the hydrazine N—H group and the carbonyl group in the β-position from the hydrazine N—H group. The electrostatic properties of the molecule were derived from the molecular charge density. The molecule is in a lengthened conformation and the rings of the two benzyl groups are nearly orthogonal. Results from a high-field 1H and 13C NMR correlation spectroscopy study confirm that the same tautomer exists in solution as in the solid state.
The overall conformation of the title molecule, C14H11BrO3S, is L-shaped, as seen in the value of the dihedral angle formed between the terminal benzene rings of 75.44 (13)°. The presence of C—H⋯O interactions leads to the formation of linear supramolecular chains along the a-axis direction in the crystal structure. These are connected into supramolecular arrays in the ab plane via C—H⋯π contacts.
The title compound, C18H19NO5, is a product of the Hantzsch reaction of p-phthalaldehyde, methyl acetoacetate, and ammonium acetate. The 1,4-dihydropyridine ring of the molecule adopts a flattened boat conformation. The benzene ring is almost perpendicular to the 1,4-dihydropyridine ring; the plane through the six C atoms of the benzene ring and the plane through the four C atoms that form the base of the boat-shaped 1,4-dihydropyridine ring (excluding the ring N atom and the opposite ring C atom) make a dihedral angle of 87.60 (3)°. Intermolecular N—H⋯O hydrogen bonds result in the formation of extended chains along the a axis.
In the title compound, C26H24BrNO5·H2O, a synthetic analogue of natural flavagline, the cyclopentane ring adopts an envelope conformation (the flap atom bearing the phenyl group) and the vicinal phenyl and bromophenyl groups are slightly shifted relative to each other [CPh—C—C—CPhBr = 36.3 (2)°]. Intramolecular N—H⋯O and C—H⋯O hydrogen bonds form S(5) motifs. In the crystal, the organic and the water molecules are linked by an O—H⋯O hydrogen bond. Pairs of organic and water molecules, located about inversion centers, interact through O—H⋯O hydrogen bonds, forming R
4(20) and R
4(26) motifs, which together lead to C
2(9) motifs. The crystal packing is also characterized by N—H⋯O and C—H⋯O hydrogen bonds between neighbouring organic molecules, forming R
2(10) and R
2(18) motifs, respectively.
The crystal structures of three closely related benzothiazinone structures are reported. All three are conformationally similar having screw-boat puckering in the thiazine ring and C—H⋯π-type intermolecular interactions in the crystals.
Three ring-substituted 3-aryl analogs of 2-phenyl-2,3-dihydro-4H-1,3-benzothiazin-4-one, namely 3-(4-methoxyphenyl)-2-phenyl-4H-1,3-benzothiazin-4-one, C21H17NO2S, (I), 2-phenyl-3-[4-(trifluoromethyl)phenyl]-2,3-dihydro-4H-1,3-benzothiazin-4-one toluene hemisolvate, C21H14F3NOS·0.5C7H8, (II), and 3-(3-bromophenyl)-2-phenyl-2,3-dihydro-4H-1,3-benzothiazin-4-one toluene hemisolvate, C20H14BrNOS·0.5C7H8, (III), were synthesized and their crystal structures determined. The hemisolvates differ in that in (II), the asymmetric unit comprises two molecules of the benzothiazinone compound and a toluene solvent molecule, whereas in (III), the unit comprises one benzothiazinone molecule and a half-occupancy toluene solvent molecule. All crystals are of racemic mixtures of the chiral 2-C atom of the thiazine moiety, which in all structures has a screw-boat puckering, with the puckering amplitude values within the range 0.575–0.603 Å. In all three structures, the benzene plane of the benzothiazine system makes a dihedral angle in the range 78.60 (5) to 98.40 (5)° with the unsubstituted benzene plane and in the range 70.50 (1) to 121.00 (5)° with the substituted benzene plane. The CF3 substituent group in one of the molecules of (II) shows positional disorder, with an occupancy ratio of 0.57 (3):0.43 (3). In the crystals of (I) and (II), weak intermolecular C—H⋯O interactions are present, giving in (I), molecules arranged in a plane parallel to (010), and in (II), chains along a. In addition, all three structures show weak C—H⋯π interactions involving various aromatic rings.
crystal structure; benzothiazinones; screw-boat thiazine pucker; aromatic ring interactions
In the title compound, C22H25N3O4, the dihydropyridine ring adopts a flattened boat conformation. The pyrazole ring makes a dihedral angle of 29.04 (5)° with the benzene ring. The molecular structure is stabilized by an intramolecular C—H⋯O hydrogen bond which generates an S(9) ring motif. In the crystal, molecules are linked via N—H⋯O and C—H⋯N hydrogen bonds into a two-dimensional network parallel to the ab plane. The crystal structure is further consolidated by weak C—H⋯π interactions.
The title compound, C9H10N4OS·0.5H2O, crystallizes with two independent molecules (A and B) in the asymmetric unit, together with a water molecule of crystallization. The acetamide moiety, which has an extended conformation, is inclined to the pyridine ring by 7.95 (16)° in molecule A and by 1.77 (16)° in molecule B. In the crystal, the A and B molecules are linked by two N—H⋯Ocarbonyl hydrogen bonds, forming a dimer. The dimers are linked via N—H⋯N hydrogen bonds, forming ribbons that are linked by N—H⋯Owater hydrogen bonds to form sheets parallel to (110). The sheets are linked by O—H⋯N hydrogen bonds, forming slabs, and between the slabs there are weak slipped parallel π–π interactions [inter-centroid distance = 3.734 (2) Å, interplanar distance = 3.3505 (11) Å and slippage = 1.648 Å], forming a three-dimensional structure.
crystal structure; poly-functional pyridines; acetamide; disorder; hydrogen bonding
In the title compound, C17H17Cl2NO2, the central 1,4-dihydropyridine ring adopts a flattened-boat conformation. The ethanone substituents of the dihydropyridine ring at positions 3 and 5 have synperiplanar (cis) or antiperiplanar (trans) conformations with respect to the adjacent C=C bonds in the dihydropyridine ring. The 2,4-dichlorophenyl ring is almost planar [r.m.s. deviation = 0.0045 (1) Å] and almost perpendicular [89.27 (3)°] to the mean plane of the dihydropyridine ring. In the crystal, an N—H⋯O hydrogen bond links molecules into a zigzag chain along the ac diagonal. C—H⋯Cl contacts form centrosymmetric dimers and additional weak C—H⋯O contacts further consolidate the packing.
In the molecular structure of the title compound, C22H27NO6, the dihydropyridine ring adopts a flattened boat conformation while the cyclohexenone ring is in an envelope conformation. In the crystal, molecules stack parallel to the crystallographic a axis linked by intermolecular N—H⋯O and C—H⋯O hydrogen bonds.
In the molecular structure of the title compound, C21H25NO4, the dihydropyridine ring adopts a flattened boat conformation while the cyclohexenone ring is in an envelope conformation. In the crystal structure, molecules are linked into a two-dimensional network parallel to (10) by N—H⋯O and O—H⋯O hydrogen bonds. The network is generated by R
4(30) and R
4(34) graph-set motifs.
The asymmetric unit of the title compound, [Hg(C13H10N3O2)Cl]·H2O, contains two independent mercury(II) complexes with slightly different conformations, related via a pseudo-inversion centre, and two water molecules. The HgII atoms show a typical linear geometry to a C atom of the benzene ring and to a Cl atom. A benzene C and the azomethine N atom chelate the HgII atoms with weak intramolecular Hg⋯N bonding distances of 2.735 (3) and 2.739 (3) Å, respectively. The resulting five-membered metallacycles are nearly coplanar with the benzene rings [dihedral angles = 0.9 (1) and 0.7 (1)°], while the pyridine rings make dihedral angles with the benzene units of 58.17 (1) and 56.58 (1)°. In the crystal structure, the HgII complexes are linked by hydroxy donor and pyridine acceptor groups into chains along . The water molecules connect the complexes through intermolecular O—H⋯Ocarbonyl bonds in the a-axis direction, and the azomethine H atoms donate towards the water O atoms, forming a three-dimensional network of intermolecular O—H⋯N, O—H⋯O and N—H⋯O hydrogen bonds.
The title compound, C14H11BrN4O4, contains 3-bromophenyl and 2,4-dinitrophenyl groups on opposite sides of a hydrazone unit and crystallizes with two molecules in the asymmetric unit. The dihedral angles between the two ring systems in each molecule are 2.0 (1) and 2.5 (4)°. Weak C—H⋯O hydrogen bonds and weak π–π stacking interactions [centroid–centroid distance = 3.7269 (14) Å] help to establish the packing. Intramolecular N—H⋯O hydrogen bonds are also observed. On one of the rings, the Br atom is disordered over two equivalent positions of the phenyl ring [occupancy ratio 0.8734 (10):0.1266 (10).
The conformation of the N—H bond in the structure of the title compound, C8H8BrNO, is anti to the C=O bond and to the meta-bromo substituent of the aromatic ring in both independent molecules comprising the asymmetric unit. Molecules are linked through N—H⋯O hydrogen bonding into supramolecular chains with a twisted topology.
In the title molecule, C15H10BrNO3S2, the dihedral angle between the benzothiazole ring system and the benzene ring is 67.57 (12)°. The crystal structure is stabilized by weak intermolecular C—H⋯O interactions. In addition, there is an intermolecular Br⋯C [3.379 (3) Å] contact which is shorter than the sum of the van der Waals radii of these atoms.
The title compound, C21H20BrNO2, was obtained from a condensation reaction of 4-bromobenzaldehyde, 2-naphthol and morpholine. The molecular conformation is stabilized by an intramolecular O—H⋯N hydrogen bond, closing a six-membered ring. The dihedral angle between the naphthalene ring system and the benzene ring is 76.72 (8)°. In addition to the intramolecular hydrogen bond, the O—H groups of centrosymmetrically related molecules form short intermolecular H⋯O contacts of 2.59 Å. These molecules are also linked by pairs of C—H⋯O interactions, generating an R
The asymmetric unit of the title compound, C25H35NO6, contains two independent molecules. In each molecule, the 1,4-dihydropyridine ring adopts a flattened boat conformation. The dihedral angles between the 1,4-dihydropyridine and benzene rings are 87.55 (7) and 87.23 (7)°. In one of these molecules, one of the isobutyl groups is disordered over two sets of sites, with an occupancy ratio of 0.890 (2):0.110 (2). In the crystal, molecules are linked through N—H⋯O, O—H⋯O and C—H⋯O hydrogen bonds forming two-dimensional networks parallel to the ab plane. The crystal structure is further stabilized by weak C—H⋯π interactions.
In the title compound, C8H12N2·H2O, four substituted pyridine molecules alternate with four water molecules, forming a large ring via Owater—H⋯Npyridine and Namine—H⋯Owater hydrogen bonding. Adjacent rings are connected via Owater—H⋯Owater hydrogen-bonds, forming a three-dimensional network.