Reduced 3,4'-bi-pyrazoles carrying thio-phene and thia-zole substituents: structures of two intermediates and two products.

Cyclo-addition reactions between 3-(5-ar-yloxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)-1-(thio-phen-2-yl)prop-2-en-1-ones and thio-semicarbazide leads to the formation of reduced 3,4'-bi-pyrazole-2-carbo-thio-amides. Further cyclo-addition of these inter-mediates with either diethyl acetyl-enedi-carboxyl-ate or 4-bromo-phenacyl bromide leads to reduced 3,4'-bi-pyrazoles carrying oxo-thia-zole or thia-zole substituents, respectively. The structures of two representative inter-mediates and two representative products established unambiguously the regiochemistry of the cyclo-addition reactions. The mol-ecules of 3'-methyl-5'-(2-methyl-phen-oxy)-1'-phenyl-5-(thio-phen-2-yl)-3,4-di-hydro-1'H,2H-3,4'-bi-pyra-zole-2-carbo-thio-amide, C25H23N5OS2 (Ia), are linked by N-H⋯N hydrogen bonds to form simple C(8) chains. The analogous compound 5'-(2,4-di-chloro-phen-oxy)-3'-methyl-1'-phenyl-5-(thio-phen-2-yl)-3,4-di-hydro-1'H,2H-3,4'-bi-pyra-zole-2-carbo-thio-amide hemihydrate crystallizes as a hemihydrate, C24H19Cl2N5OS2·0.5H2O (Ib), and the independent components are linked into a chain of spiro-fused R 4 4(20) rings by a combination of O-H⋯N and N-H⋯O hydrogen bonds. In the structure of ethyl (Z)-2-{2-[3'-methyl-1'-phenyl-5-(thio-phen-2-yl)-5'-(2-methyl-phen-oxy)-3,4-di-hydro-1'H,2H-3,4'-bi-pyrazole-2-yl]-4-oxo-4,5-di-hydro-thia-zol-5-yl-idene}acetate, C31H27N5O4S2 (II), inversion-related pairs of mol-ecules are linked by paired C-H⋯π(arene) hydrogen bonds to form cyclic centrosymmetric dimers, but there are no direction-specific inter-molecular inter-actions in 4-(4-bromo-phen-yl)-2-[5'-(2,4-di-chloro-phen-oxy)-3'-methyl-1'-phenyl-5-(thio-phen-2-yl)-3,4-di-hydro-1'H,2H-3,4'-bi-pyrazole-2-yl]-4-thia-zole, C32H22BrCl2N5OS2 (III). Comparisons are made with the structures of some related compounds.

The crystal structures of three disordered 2-substituted benzimidazole esters.

The crystal structures of three benzimidazole esters containing aryl or heterocyclic substituents at position 2 are reported, and all three exhibit disorder of mol-ecular entities. In ethyl 1-methyl-2-[4-(prop-2-yn-oxy)phen-yl]-1H-benzimidazole-5-carboxyl-ate, C20H18N2O3, (I), the prop-2-yn-1-oxyphenyl unit is disordered over two sets of atomic sites having effectively equal occupancies, 0.506 (5) and 0.494 (5). The propyl substituent in ethyl 1-propyl-2-(pyren-1-yl)-1H-benzimidazole-5-carboxyl-ate, C29H24N2O2, (II), is disordered over two sets of atomic sites having occupancies 0.601 (8) and 0.399 (8), and the ester unit in ethyl 1-methyl-2-(5-chloro-3-methyl-1-phenyl-1H-pyrazol-4-yl)-1H-benzimidazole-5-carboxyl-ate, C21H19ClN4O2 (III), is disordered over two sets of atomic sites having occupancies 0.645 (7) and 0.355 (7). In each of the C-H⋯π(arene) hydrogen bonds in (I), the donor and acceptor form parts of different disorder components, so that no continuous aggregation is possible. The mol-ecules of (II) are linked by a single C-H⋯O hydrogen bond into C(10) chains, which are linked into sheets by a π-π stacking inter-action, whereas those of (III) are just linked into C(13) chains, again by a single C-H⋯O hydrogen bond. Comparisons are made with the structures of some related compounds.

Six 1-halobenzoyl-4-(2-meth-oxy-phen-yl)piperazines having Z' values of one, two or four; disorder, pseudosymmetry, twinning and supra-molecular assembly in one, two or three dimensions.

Six 1-halobenzoyl-4-(2-meth-oxy-phen-yl)piperazines have been prepared using carbodi-imide-mediated coupling reactions between halo-benzoic acids and N-(2-meth-oxy-phen-yl)piperazine. The mol-ecules of 1-(4-fluoro-benzo-yl)-4-(2-meth-oxy-phen-yl)piperazine, C18H19FN2O2 (I), are linked into a chain of rings by a combination of C-H⋯O and C-H⋯π(arene) hydrogen bonds. 1-(4-Chloro-benzo-yl)-4-(2-meth-oxy-phen-yl)piperazine, C18H19ClN2O2 (II), crystallizes in the space group Pca21 with Z' = 4 and it exhibits both pseudosymmetry and inversion twinning: a combination of six C-H⋯O and two C-H⋯π(arene) hydrogen bonds generate a three-dimensional assembly. In 1-(4-bromo-benzo-yl)-4-(2-meth-oxy-phen-yl)piperazine, C18H19BrN2O2 (III), which also crystallizes in space group Pca21 but with Z' = 2, the bromo-benzoyl unit in one of the mol-ecules is disordered. Pseudosymmetry and inversion twinning are again present, and a combination of three C-H⋯O and one C-H⋯π(arene) hydrogen bonds generate a two-dimensional assembly. A single C-H⋯O hydrogen bond links the mol-ecules of 1-(4-iodo-benzo-yl)-4-(2-meth-oxy-phen-yl)piperazine, C18H19IN2O2 (IV), into simple chains but in the isomeric 3-iodo-benzoyl analogue (V), which crystallizes in space group P212121 with Z' = 2, a two-dimensional assembly is generated by a combination of four C-H⋯O and two C-H⋯π(arene) hydrogen bonds; pseudosymmetry and inversion twinning are again present. A single C-H⋯O hydrogen bond links the mol-ecules of 1-(2-fluoro-benzo-yl)-4-(2-meth-oxy-phen-yl)piperazine, C18H19FN2O2 (VI), into simple chains. Comparisons are made with the structures of some related compounds.

Fifteen 4-(2-meth-oxy-phen-yl)piperazin-1-ium salts containing organic anions: supra-molecular assembly in zero, one, two and three dimensions.

Fifteen 4-(2-meth-oxy-phen-yl)piperazin-1-ium salts containing organic anions have been prepared and structurally characterized. In the isostructural 4-chloro-benzoate and 4-bromo-benzoate salts, C11H17N2O+·C7H4ClO2 - (I) and C11H17N2O+·C7H4BrO2 - (II), and the 4-iodo-benzoate salt C11H17N2O+·C7H4IO2 - (III), the ions are linked by N-H⋯O hydrogen bonds, forming centrosymmetric R 4 4(12) four-ion aggregates; a similar aggregate is formed in the 2-chloro-benzoate salt (V), isomeric with (I). In the 2-fluoro-benzoate salt C11H17N2O+·C7H4FO2 - (IV), and the isomorphous pair of salts, the 2-bromo-benzoate (VI), isomeric with (II) and 2-iodo-benzoate (VII), isomeric with (III), N-H⋯O and C-H⋯π(arene) interactions link the components into three-dimensional arrays. Four-ion R 4 4(12) aggregates are also found in the 2-methyl-benzoate, 4-amino-benzoate and 4-nitro-benzoate salts, C11H17N2O+·C8H7O2 - (VIII), C11H17N2O+·C7H6NO2 - (IX) and C11H17N2O+·C7H4NO4 - (X), but those in (IX) are linked into complex sheets by an additional N-H⋯O hydrogen bond. In the 3,5-dinitrobenzoate salt, C11H17N2O+·C7H3N2O6 -·2H2O (XI), N-H⋯O and O-H⋯O hydrogen bonds link the components into a complex ribbon structure. In the picrate salt, C11H17N2O+·C6H2N3O7 - (XII), the four-ion aggregates are linked into chains of rings by C-H⋯O hydrogen bonds. In the hydrogen maleate salt, C11H17N2O+·C4H3O4 - (XIII), two- and three-centre hydrogen bonds link the ions into a ribbon structure while both anions contain very short but asymmetric O-H⋯O hydrogen bonds, having O⋯O distances of 2.4447 (16) and 2.4707 (17) Å. O-H⋯O Hydrogen bonds link the anions in the hydrogen fumarate salt (XIV), isomeric with (XIII), into chains that are linked into sheets via N-H⋯O hydrogen bonds. In the hydrogen (2R,3R)-tartrate salt, C11H17N2O+·C4H5O6 -·1.698H2O (XV), the anions are linked into sheets by O-H⋯O hydrogen bonds. Comparisons are made with the structures of some related compounds.

The crystal structures of salts of N-(4-fluoro-phen-yl)piperazine with four aromatic carb-oxy-lic acids and with picric acid.

The structures are reported for five salts formed by reactions between N-(4-fluoro-phen-yl)piperazine and aromatic acids. In 4-(4-fluoro-phen-yl)piperazin-1-ium 2-fluoro-benzoate monohydrate, C10H14FN2 +·C7H4FO2 -·H2O, (I), the components are linked by a combination of N-H⋯O and O-H⋯O hydrogen bonds to form a chain of alternating R 4 6(12) and R 6 6(16) rings. The ionic components of 4-(4-fluoro-phen-yl)piperazin-1-ium 2-bromo-benzoate 0.353-hydrate, C10H14FN2 +·C7H4BrO2 -·0.353H2O, (II), are linked by N-H⋯O hydrogen bonds to form a centrosymmetric four-ion aggregate containing an R 4 4(12) motif, and these aggregates are linked into a mol-ecular ladder by a single C-H⋯π(arene) hydrogen bond. 4-(4-Fluoro-phen-yl)piperazin-1-ium 2-iodo-benzoate, C10H14FN2 +·C7H4IO2 -, (III), crystallizes with Z' = 2 in space group P : the four independent ions are linked by N-H⋯O hydrogen bonds to form a non-centrosymmetric aggregate again containing an R 4 4(12) motif, and aggregates of this type are linked into a ribbon by a combination of C-H⋯O and C-H⋯π(arene) hydrogen bonds. The anion in 4-(4-fluoro-phen-yl)piperazin-1-ium 2,4,6-tri-nitro-phenolate, C10H14FN2 +·C6H2N3O7 -, (IV), shows clear evidence of extensive electronic delocalization from the phenolate O atom into the adjacent ring. The ions are linked by a combination of two-centre N-H⋯O and three-centre N-H⋯(O)2 hydrogen bonds to form centrosymmetric four-ion aggregates containing three types of ring. The ions in 4-(4-fluoro-phen-yl)piperazin-1-ium 3,5-di-nitro-benzoate, C10H14FN2 +·C7H3N2O6 -, (V), are again linked by N-H⋯O hydrogen bonds to form centrosymmetric R 4 4(12) aggregates, which are themselves linked by a C-H⋯π(arene) hydrogen bond to form sheets, the stacking of which leads to the formation of narrow channels, containing disordered and/or mobile solvent entities. Comparisons are made with some related structures.

Two N-{[4-(3-aryl-4-sydnonyl-idene-amino)-5-sulfan-yl-idene-1H-1,2,4-triazol-3-yl]meth-yl}benzamides as disordered ethanol monosolvates.

Two new N-{[4-(3-aryl-4-sydnonyl-idene-amino)-5-sulfanyl-idene-1H-1,2,4-triazol-3-yl]meth-yl}benzamides have been prepared by acid-promoted condensation reactions between 3-aryl-4-formyl-sydnones and N-[(4-amino-5-sulfanyl-idene-1H-1,2,4-triazol-3-yl)meth-yl]benzamide, and both have been crystallized as ethanol monosolvates. N-{[4-(3-Phenyl-4-sydnonyl-idene-amino)-5-sulfanyl-idene-1H-1,2,4-triazol-3-yl]meth-yl}benzamide ethanol monosolvate, C19H15N7O3S·C2H6O (I), and N-({4-[3-(4-methyl-phen-yl)-4-sydnonyl-idene-amino]-5-sulfanyl-idene-1H-1,2,4-triazol-3-yl}meth-yl)benzamide ethanol monosolvate, C20H17N7O3S·C2H6O (II), differ only in the presence of a methyl group for (II) instead of a hydrogen atom for (I), and in both of them the ethanol component is disordered over two sets of atomic sites having occupancies of 0.836 (6) and 0.164 (6) in (I), and 0.906 (6) and 0.094 (6) in (II). Combinations of O-H⋯O and N-H⋯O hydrogen bonds link the mol-ecules into cyclic, centrosymmetric four-mol-ecule aggregates. Comparisons are made with the structures of some related compounds.

Three 4-(4-fluoro-phen-yl)piperazin-1-ium salts containing organic anions: supra-molecular assembly in one, two and three dimensions.

Three salts containing the 4-(4-fluoro-phen-yl)piperazin-1-ium cation have been prepared and structurally characterized. In 4-(4-fluoro-phen-yl)piperazin-1-ium 2-hy-droxy-3,5-di-nitro-benzoate, C10H14FN2 +·C7H3N2O7 -, (I), the anion contains an intra-molecular O-H⋯O hydrogen bond, and it has a structure similar to that of the picrate ion. The cations and anions are linked into [001] chains of rings by a combination of two three-centre N-H⋯(O)2 hydrogen bonds. The anion in 4-(4-fluoro-phen-yl)piperazin-1-ium hydrogen oxalate, C10H14FN2 +·C2HO4 -, (II), is planar, and the cations and anions are linked into (100) sheets by multiple hydrogen bonds including two-centre N-H⋯O, three-centre N-H⋯(O)2, O-H⋯O, C-H⋯O and C-H⋯π(arene) types. In 4-(4-fluoro-phen-yl)piperazin-1-ium hydrogen (2R,3R)-tartrate monohydrate, C10H14FN2 +·C4H5O6 -·H2O, (III), the anion exhibits an approximate non-crystallographic twofold rotation symmetry with anti-periplanar carboxyl groups. A combination of eight hydrogen bonds, encompassing two- and three-centre N-H⋯O systems, O-H⋯O and C-H⋯π(arene) types, link the independent components into a three-dimensional framework. Comparisons are made with some related structures.

Crystal structures of the recreational drug N-(4-meth-oxy-phen-yl)piperazine (MeOPP) and three of its salts.

Crystal structures are reported for N-(4-meth-oxy-phen-yl)piperazine (MeOPP), (I), and for its 3,5-di-nitro-benzoate, 2,4,6-tri-nitro-phenolate (picrate) and 4-amino-benzoate salts, (II)-(IV), the last of which crystallizes as a monohydrate. In MeOPP, C11H16N2O, (I), the 4-meth-oxy-phenyl group is nearly planar and it occupies an equatorial site on the piperazine ring: the mol-ecules are linked into simple C(10) chains by N-H⋯O hydrogen bonds. In each of the salts, i.e., C11H17N2O+·C7H3N2O6 -, (II), C11H17N2O+·C6H2N3O7 -, (III), and C11H17N2O+·C7H6NO2 -·H2O, (IV), the effectively planar 4-meth-oxy-phenyl substituent again occupies an equatorial site on the piperazine ring. In (II), two of the nitro groups are disordered over two sets of atomic sites and the bond distances in the anion indicate considerable delocalization of the negative charge over the C atoms of the ring. The ions in (II) are linked by two N-H⋯O hydrogen bonds to form a cyclic, centrosymmetric four-ion aggregate; those in (III) are linked by a combination of N-H⋯O and C-H⋯π(arene) hydrogen bonds to form sheets; and the components of (IV) are linked by N-H⋯O, O-H⋯O and C-H⋯π(arene) hydrogen bonds to form a three-dimensional framework structure. Comparisons are made with the structures of some related compounds.

1-(3,5-Di-nitro-benzo-yl)-4-(2-meth-oxy-phen-yl)piper-azine.

In the title compound, C18H18N4O6, the piperazine ring adopts a chair conformation, the amidic N atom is planar (sum of angles = 360°) and the non-amidic N atom is pyramidal (343°). There are no hydrogen bonds of any kind in the crystal, but the mol-ecules are linked by two independent π(nitro-benzene)⋯π(meth-oxy-benzene) stacking inter-actions to form π-stacked sheets with inter-centroid separations of 3.8444 (12) and 3.9197 (12) Å.