The crystal structure of (RS)-7-chloro-2-(2,5-di-meth-oxy-phen-yl)-2,3-di-hydro-quinazolin-4(1H)-one: two hydrogen bonds generate an elegant three-dimensional framework structure.

In the title compound, C61H15ClN2O3, the heterocyclic ring adopts an envelope conformation, folded across the N⋯N line, with the 2,5-di-meth-oxy-phenyl unit occupying a quasi-axial site. There are two N-H⋯O hydrogen bonds in the structure: one hydrogen bond links mol-ecules related by a 41 screw axis to form a C(6) chain, and the other links inversion-related pairs of mol-ecules to form an R 2 2(8) ring. The ring motif links all of the chains into a continuous three-dimensional framework structure. Comparisons are made with the structures of some related compounds.

Six 1-aroyl-4-(4-meth-oxy-phen-yl)piperazines: similar mol-ecular structures but different patterns of supra-molecular assembly.

Six new 1-aroyl-4-(4-meth-oxy-phen-yl)piperazines have been prepared, using coupling reactions between benzoic acids and N-(4-meth-oxy-phen-yl)piperazine. There are no significant hydrogen bonds in the structure of 1-benzoyl-4-(4-meth-oxy-phen-yl)piperazine, C18H20N2O2, (I). The mol-ecules of 1-(2-fluoro-benzo-yl)-4-(4-meth-oxy-phen-yl)piperazine, C18H19FN2O2, (II), are linked by two C-H⋯O hydrogen bonds to form chains of rings, which are linked into sheets by an aromatic π-π stacking inter-action. 1-(2-Chloro-benzo-yl)-4-(4-meth-oxy-phen-yl)piperazine, C18H19ClN2O2, (III), 1-(2-bromo-benzo-yl)-4-(4-meth-oxy-phen-yl)piperazine, C18H19BrN2O2, (IV), and 1-(2-iodo-benzo-yl)-4-(4-meth-oxyphen-yl)piperazine, C18H19IN2O2, (V), are isomorphous, but in (III) the aroyl ring is disordered over two sets of atomic sites having occupancies of 0.942 (2) and 0.058 (2). In each of (III)-(V), a combination of two C-H⋯π(arene) hydrogen bonds links the mol-ecules into sheets. A single O-H⋯O hydrogen bond links the mol-ecules of 1-(2-hy-droxy-benzo-yl)-4-(4-meth-oxy-phen-yl)piperazine, C18H20N2O3, (VI), into simple chains. Comparisons are made with the structures of some related compounds.

Hydrogen-bonded mol-ecular salts of reduced benzo-thia-zole derivatives with carboxyl-ates: a robust (8) supra-molecular motif (even when disordered).

The syntheses and structures of five mol-ecular salts of protonated 4,4,7,7-tetra-methyl-3a,5,6,7a-tetra-hydro-benzo-thia-zol-2-yl-amine (C11H19N2S+) with different deprotonated carb-oxy-lic acids (4-methyl-benzoic acid, 4-bromo-benzoic acid, 3,5-di-nitro-benzoic acid, fumaric acid and succinic acid) are reported, namely 2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium 4-methyl-benzoate, C11H19N2S+·C8H7O2 -, (I), 2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium 4-bromo-benzoate, C11H19N2S+·C7H4BrO2 -, (II), 2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium 3,5-di-nitro-benzoate, C11H19N2S+·C7H3N2O6 -, (III), bis-(2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium) fumarate, 2C11H19N2S+·C4H2O4 2-,(IV), and the 1:1 co-crystal of bis-(2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium) succinate and 2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium hydrogen succin-ate 4,4,7,7-tetra-methyl-3a,5,6,7a-tetra-hydro-benzo-thia-zol-2-yl-amine, 1.5C11H19N2S+·0.5C4H4O4 2-·0.5C4H5O4 -. 0.5C11H18N2S, (V). In every case, the cation protonation occurs at the N atom of the thia-zole ring and the six-membered ring adopts a half-chair conformation (in some cases, the deviating methyl-ene groups are disordered over two sets of sites). The C-N bond lengths of the nominal -NH+=C-NH2 fragment of the cation are indistinguishable, indicating a significant contribution of the -NH-C=N+H2 resonance form to the structure. The packing for (I)-(V) features a robust local R 2 2(8) loop motif in which the cation forms two near-linear N-H⋯O hydrogen bonds from the N+-H group and syn H atom of the amine group to the carboxyl-ate group of an adjacent anion [(V) shows disorder of one of these bonds over N-H⋯O and N⋯H-O contributors but the same R 2 2(8) loop results for both disorder components]. The anti H atom of the -NH2 group also forms an N-H⋯O hydrogen bond, which results in [001] chains in (I) and (II), isolated centrosymmetric tetra-mers in (III) and [100] chains in (IV) and (V). Hirshfeld fingerprint plots and contact percentages for the different types of contacts of the cations are discussed.

Three closely related 1-[(1,3-benzodioxol-5-yl)methyl]-4-(halobenzo-yl)piperazines: similar mol-ecular structures but different inter-molecular inter-actions.

In each of the compounds 1-[(1,3-benzodioxol-5-yl)methyl]-4-(3-fluoro-benzo-yl)piperazine, C19H19FN2O3 (I), 1-[(1,3-benzodioxol-5-yl)methyl]-4-(2,6-di-fluoro-benzo-yl)piperazine, C19H18F2N2O3 (II), and 1-[(1,3-benzodioxol-5-yl)methyl]-4-(2,4-di-chloro-benzo-yl)piperazine, C19H19Cl2N2O3 (III), the piperazine rings adopt a chair conformation with the (1,3-benzodioxol-5-yl)methyl substituent occupying an equatorial site: the five-membered rings are all slightly folded across the O⋯O line leading to envelope conformations. The dihedral angle between the planar amidic fragment and the haloaryl ring is 62.97 (5)° in (I) but 77.72 (12)° and 75.50 (5)° in (II) and (III), respectively. Despite their similarity in constitution and conformation, the supra-molecular inter-actions in (I)-(III) differ: in (I), a combination of C-H⋯O and C-H⋯π(arene) hydrogen bonds links the mol-ecules into a three-dimensional framework structure, but there are no hydrogen bonds of any sort in either (II) or (III), although the structure of (III) contains a short Cl⋯Cl contact between inversion-related pairs of mol-ecules.

Eight Schiff bases derived from various salicylaldehydes: phenol-imine and keto-amine forms, conformational disorder, and supramolecular assembly in one and two dimensions.

Structures are reported for eight Schiff bases derived from various salicylaldehydes: five are newly synthesized and re-investigations are reported for three previously reported structures, leading, in each case, to some revision of previous conclusions. In (E)-N-(3,4-dimethylisoxazol-5-yl)-4-[(2-hydroxybenzylidene)amino]benzenesulfonamide, C18H17N3O4S, (I), and (E)-4-[(5-bromo-2-hydroxy-3-methoxybenzylidene)amino]-N-(3,4-dimethylisoxazol-5-yl)benzenesulfonamide. C19H18BrN3O5S, (II), the isoxazole rings adopt different orientations relative to the rest of the molecules, despite the additional substituents in (II) being in the aryl ring remote from the isoxazole unit. The molecules of both (E)-4-bromo-2-[(2-hydroxyphenylimino)methyl]-6-methoxyphenol, C14H12BrNO3, (III), and (E)-4-bromo-2-methoxy-6-[(2-methoxyphenylimino)methyl]phenol, C15H14BrNO3, (IV), are both effectively planar; while (III) adopts the phenol-imine constitution, (IV) adopts the keto-amine constitution. (E)-2-Methoxy-6-[(2-methoxyphenylimino)methyl]phenol, C15H15NO3, (V), which was determined previously using powder X-ray data assuming the phenol-imine constitution, has now been refined from single-crystal X-ray data, confirming the phenol-imine constitution. In (E)-3-benzoyl-2-[(5-fluoro-2-hydroxybenzylidene)amino]-4,5,6,7-tetrahydrobenzo[b]thiophene, C22H18FNO2S, (VI), the fused carbocyclic ring exhibits conformational disorder; both disorder components, having populations of 0.705 (4) and 0.295 (4), adopt half-chair conformations. The isostructural (E)-3-benzoyl-2-[(2-hydroxybenzylidene)amino)]-4,5,6,7-tetrahydrobenzo[b]thiophene, C22H19NO2S, (VII), which was originally reported as having a fully ordered structure [Kaur et al. (2014). Acta Cryst. E70, o476-o477], has been rerefined using the original data set and found to exhibit the same type of disorder as found in (VI), with disordered populations having occupancies of 0.851 (3) and 0.149 (3). The triclinic polymorph of (E)-[(2-hydroxyphenylimino)methyl]phenol, C13H11NO2, (VIII), which crystallizes with Z' = 2 in the space group P-1, has been described variously as occurring as the keto-amine tautomer [Maciejewska et al. (1999). J. Phys. Org. Chem. 12, 875-880] and as the phenol-imine tautomer [Tunç et al. (2009). J. Chem. Crystallogr. 39, 672-676]. Rerefinement of this structure using one of the original data sets shows that both of the independent molecules exist in the keto-amine form. In the structures of compounds (I), (VI), (VII) and (VIII), hydrogen bonds generate simple chains, while a chain of rings is formed in (V). Sheets are formed by hydrogen bonds in both (II) and (III), while in (IV), the sheet structure is built from aromatic π-π stacking interactions.

The crystal structure of (E)-2-ethyl-N-(4-nitro-benzyl-idene)aniline: three-dimensional supra-molecular assembly mediated by C-H⋯O hydrogen bonds and nitro⋯π(arene) inter-actions.

In the mol-ecule of the title compound, C15H14N2O2, the 2-ethyl-phenyl group is disordered over two sets of atomic sites having occupancies of 0.515 (19) and 0.485 (19), and the dihedral angle between the two partial-occupancy aryl rings is 6(2)°. A combination of C-H⋯O hydrogen bonds and nitro⋯π(arene) inter-actions links the mol-ecules into a continuous three-dimensional framework structure. Comparisons are made with the structures of some related compounds.

Synthesis and structures of six closely related N-[3-(2-chlorobenzoyl)-5-ethylthiophen-2-yl]arylamides, together with an isolated reaction intermediate: order versus disorder, molecular conformations and hydrogen bonding in zero, one and two dimensions.

Six closely related N-[3-(2-chlorobenzoyl)-5-ethylthiophen-2-yl]arylamides have been synthesized and structurally characterized, together with a representative reaction intermediate. In each of N-[3-(2-chlorobenzoyl)-5-ethylthiophen-2-yl]benzamide, C20H16ClNO2S, (I), N-[3-(2-chlorobenzoyl)-5-ethylthiophen-2-yl]-4-phenylbenzamide, C26H20ClNO2S, (II), and 2-bromo-N-[3-(2-chlorobenzoyl)-5-ethylthiophen-2-yl]benzamide, C20H15BrClNO2S, (III), the molecules are disordered over two sets of atomic sites, with occupancies of 0.894 (8) and 0.106 (8) in (I), 0.832 (5) and 0.168 (5) in (II), and 0.7006 (12) and 0.2994 (12) in (III). In each of N-[3-(2-chlorobenzoyl)-5-ethylthiophen-2-yl]-2-iodobenzamide, C20H15ClINO2S, (IV), and N-[3-(2-chlorobenzoyl)-5-ethylthiophen-2-yl]-2-methoxybenzamide, C21H18ClNO3S, (V), the molecules are fully ordered, but in N-[3-(2-chlorobenzoyl)-5-ethylthiophen-2-yl]-2,6-difluorobenzamide, C20H14ClF2NO2S, (VI), which crystallizes with Z' = 2 in the space group C2/c, one of the two independent molecules is fully ordered, while the other is disordered over two sets of atomic sites having occupancies of 0.916 (3) and 0.084 (3). All of the molecules in compounds (I)-(VI) exhibit an intramolecular N-H...O hydrogen bond. The molecules of (I) and (VI) are linked by C-H...O hydrogen bonds to form finite zero-dimensional dimers, which are cyclic in (I) and acyclic in (VI), those of (III) are linked by C-H...π(arene) hydrogen bonds to form simple chains, and those of (IV) and (V) are linked into different types of chains of rings, built in each case from a combination of C-H...O and C-H...π(arene) hydrogen bonds. Two C-H...O hydrogen bonds link the molecules of (II) into sheets containing three types of ring. In benzotriazol-1-yl 3,4-dimethoxybenzoate, C15H13N3O4, (VII), the benzoate component is planar and makes a dihedral angle of 84.51 (6)° with the benzotriazole unit. Comparisons are made with related compounds.

Four closely related N-(3-benzoyl-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)benzamides: order versus disorder, and similar molecular conformations but different modes of supramolecular aggregation, with a new disordered refinement of 2-amino-3-benzoyl-4,5,6,7-tetrahydrobenzo[b]thiophene.

Four closely related N-(3-benzoyl-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)benzamides, bearing different substituents on the benzamide ring, have been synthesized and structurally characterized. In each of N-(3-benzoyl-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-3-fluorobenzamide, C22H18FNO2S, (I), N-(3-benzoyl-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-4-chlorobenzamide, C22H18ClNO2S, (II), N-(3-benzoyl-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-2,6-difluorobenzamide, C22H17F2NO2S, (III), and N-(3-benzoyl-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-2-methoxybenzamide, C23H21NO3S, (IV), the last of which crystallizes with Z' = 2 in the space group P-1, the fused six-membered ring adopts a half-chair conformation. In each of (I)-(III), this ring is disordered over two sets of atomic sites having occupancies of 0.811 (6) and 0.189 (6) in (I), 0.645 (7) and 0.355 (7) in (II), and 0.784 (6) and 0.216 (6) in (III), such that the two disorder components of the ring are almost enantiomeric. Molecules of (I) are linked into chains by π-π stacking interactions, and those of (II) are linked into chains by a C-H...π hydrogen bond. A combination of two C-H...O hydrogen bonds and two C-H...π hydrogen bonds links the molecules of (III) into complex sheets, but the molecules of (IV) are linked by a combination of two hydrogen bonds, one each of the C-H...O and C-H...π types, to form centrosymmetric tetramers. The structures of (I)-(IV) are compared with that of the unsubstituted analogue N-(3-benzoyl-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)benzamide and a new refinement of the parent amine 2-amino-3-benzoyl-4,5,6,7-tetrahydrobenzo[b]thiophene, using the original data set, has found that here too the fused six-membered ring exhibits conformational disorder, with occupancies of 0.887 (9) and 0.113 (9). Comparisons are made with some related compounds.

Crystal structure of ebastinium 3,5-di-nitro-benzoate.

Ebastine, 4-(benzhydr-yloxy)-1-[4-(4-tert-butyl-phen-yl)-4-oxobut-yl]piperidine, reacts with 3,5-di-nitro-benzoic acid in methanol solution to give the title 1:1 salt, ebastinium 3,5-di-nitro-benzoate, C32H40NO2+·C7H3N2O6-. In the cation, the disubstituted aryl ring exhibits orientational disorder over two sets of atomic sites having occupancies 0.706 (4) and 0.294 (6), with a dihedral angle of 41.2 (5)° between the two orientations: the bulky Ph2CH-O- substituent occupies an axial site on the piperidine ring. The two ions in the selected asymmetric unit are linked by a nearly linear N-H⋯O hydrogen bond and this, in combination with two C-H⋯O hydrogen bonds, links the ions into complex sheets.

Crystal structures of 2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium benzoate and 2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium picrate.

In both 2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3- benzo-thia-zol-3-ium benzoate, C11H19N2S+·C7H5O2-, (I), and 2-amino-4,4,7,7-tetra-methyl-4,5,6,7-tetra-hydro-1,3-benzo-thia-zol-3-ium picrate (2,4,6-tri-nitro-phenolate), C11H19N2S+·C6H2N3O7-, (II), the cations are conformationally chiral as the six-membered rings adopt half-chair conformations, which are disordered over two sets of atomic sites giving approximately enanti-omeric disorder. For both cations, the bond lengths indicate delocalization of the positive charge comparable to that in an amidinium cation. The bond lengths in the picrate anion in (II) are consistent with extensive delocalization of the negative charge into the ring and onto the nitro groups, in two of which the O atoms are disordered over two sets of sites. In (I), the ionic components are linked by N-H⋯O hydrogen bonds to form a chain of rings, and in (II), the N-H⋯O hydrogen bonds link the components into centrosymmetric four-ion aggregates containing seven hydrogen bonded rings of four different types.

Three closely related 4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridines: synthesis, molecular conformations and hydrogen bonding in zero, one and two dimensions.

In each of 1-(4-fluorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C21H19F4N3O2S, (I), 1-(4-chlorophenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C21H19ClF3N3O2S, (II), and 1-(3-methylphenyl)-5-methylsulfonyl-3-[4-(trifluoromethyl)phenyl]-4,5,6,7-tetrahydro-1H-pyrazolo[4,3-c]pyridine, C22H22F3N3O2S, (III), the reduced pyridine ring adopts a half-chair conformation with the methylsulfonyl substituent occupying an equatorial site. Although compounds (I) and (II) are not isostructural, having the space groups Pbca and P212121, respectively, their molecular conformations are very similar, but the conformation of compound (III) differs from those of (I) and (II) in the relative orientation of the N-benzyl and methylsulfonyl substituents. In compounds (II) and (III), but not in (I), the trifluoromethyl groups are disordered over two sets of atomic sites. Molecules of (I) are linked into centrosymmetric dimers by C-H...π(arene) hydrogen bonds, molecules of (II) are linked by two C-H...O hydrogen bonds to form ribbons of R33(18) rings, which are themselves further linked by a C-Cl...π(arene) interaction, and a combination of C-H...O and C-H...π(arene) hydrogen bonds links the molecules of (III) into sheets. Comparisons are made with the structures of some related compounds.

Three closely related 1-(naphthalen-2-yl)prop-2-en-1-ones: pseudosymmetry, disorder and supramoleular assembly mediated by C-H...π and C-Br...π interactions.

It has been observed that when electron-rich naphthyl rings are present in chalcones they can participate in π-π stacking interactions, and this can play an important role in orientating inhibitors within the active sites of enzymes, while chalcones containing heterocyclic substituents additionally exhibit fungistatic and fungicidal properties. With these considerations in mind, three new chalcones containing 2-naphthyl substituents were prepared. 3-(4-Fluorophenyl)-1-(naphthalen-2-yl)prop-2-en-1-one, C19H13FO, (I), crystallizes with Z' = 2 in the space group P-1 and the four molecules in the unit cell adopt an arrangement which resembles that in the space group P21/a. Although 3-(4-bromophenyl)-1-(naphthalen-2-yl)prop-2-en-1-one, C19H13BrO, (II), with Z' = 1, is not isostructural with (I), the molecules of (I) and (II) adopt very similar conformations. In 1-(naphthalen-2-yl)-3-(thiophen-2-yl)prop-2-en-1-one, C17H12OS, (III), the thiophene unit is disordered over two sets of atomic sites, with occupancies of 0.780 (3) and 0.220 (3), which are related by a near 180° rotation of the thiophene unit about its exocyclic C-C bond. The molecules of compound (I) are linked by three independent C-H...π(arene) hydrogen bonds to form centrosymmetric octamolecular aggregates, whereas the molecules of compound (II) are linked into molecular ladders by a combination of C-H...π(arene) and C-Br...π(arene) interactions, and those of compound (III) are linked into centrosymmetric dimers by C-H...π(thiophene) interactions.

Crystal structure of 6-hy-droxy-5-(2-meth-oxy-phenoxy)-2,2'-bipyrimidin-4(3H)-one.

In the title compound, C15H12N4O4, the dihedral angle between the heterocyclic rings is 12.60 (8)°, and that between the benzene ring and the adjacent heterocyclic ring is 85.14 (6)°. In the crystal, a combination of N-H⋯O and O-H⋯O hydrogen bonds link mol-ecules related by a glide plane into a C(5) C(6)[R (2) 2(9)] chain of rings, which is a distinctly different packing motif to those observed in hydrated modifications of this compound.