tert-Butyl 2-{[5-(4-cyano-phen-yl)pyridin-3-yl]sulfon-yl}acetate.

In the title compound, C18H18N2O4S, the dihedral angle between the aromatic rings is 33.71 (9)° and an intra-molecular C-H⋯O hydrogen bond closes an S(6) ring. In the crystal, mol-ecules are linked by C-H⋯O and C-H⋯N hydrogen bonds to generate a three-dimensional network. A very weak aromatic π-π stacking inter-ction is also observed [centroid-centroid separation = 3.9524 (10) Å].

1-Fluoro-4-[(E)-2-nitro-vin-yl]benzene.

The title compound, C8H6FNO2, is almost planar (r.m.s. deviation for the non-H atoms = 0.019 Å) and the conformation across the C=C bond is trans. The C and H atoms of the side chain are disordered over two sets of sites in a 0.56 (3):0.44 (3) ratio. In the crystal, mol-ecules are linked by C-H⋯O inter-actions, thus forming C(5) chains propagating in [001].

FT-IR, Laser-Raman spectra and quantum chemical calculations of methyl 4-(trifluoromethyl)-1H-pyrrole-3-carboxylate-A DFT approach.

In this study the experimental and theoretical vibrational frequencies of a newly synthesized anti-tumor and anti-inflammatory agent namely, methyl 4-(trifluoromethyl)-1H-pyrrole-3-carboxylate have been investigated. The experimental FT-IR (4000-400cm(-1)) and Laser-Raman spectra (4000-100cm(-1)) of the molecule in solid phase have been recorded. The theoretical vibrational frequencies and optimized geometric parameters (bond lengths, bond angles and torsion angles) have been calculated using density functional theory (DFT/B3LYP: Becke, 3-parameter, Lee-Yang-Parr and DFT/M06-2X: highly parameterized, empirical exchange correlation function) with 6-311++G(d,p) basis set by Gaussian 03 software, for the first time. The assignments of the vibrational frequencies have been done by potential energy distribution (PED) analysis using VEDA 4 software. The theoretical optimized geometric parameters and vibrational frequencies have been found to be in good agreement with the corresponding experimental data and results in the literature. In addition, the highest occupied molecular orbital (HOMO) energy, the lowest unoccupied molecular orbital (LUMO) energy and the other related molecular energy values of the compound have been investigated using the same theoretical calculations.

Methyl 4-(tri-fluoro-meth-yl)-1H-pyrrole-3-carboxyl-ate.

In the title compound, C7H6F3NO2, all the non-H atoms except for one of the F atoms lie on a crystallographic mirror plane. In the crystal, the mol-ecules are linked into inversion dimers by pairs of C-H⋯F inter-actions, forming R 2 (2)(10) loops. These dimers are connected into C(6) chains along [001] through N-H⋯O hydrogen bonds. Aromatic π-π stacking inter-actions [centroid-centroid separation = 3.8416 (10) A°] connect the mol-ecules into a three-dimensional network.

An unknown solvate of 1-(2,4-di-chloro-benz-yl)-4-[(4-methyl-phen-yl)sulfon-yl]piperazine.

In the title compound, C18H20Cl2N2O2S, the piperazine ring adopts a chair conformation. The dihedral angle between the sulfonyl-bound benzene ring and the best-fit plane through the six non-H atoms of the piperazine ring is 72.22 (12)°; those between the di-chloro-benzene ring and the sulfonyl and piperazine rings are 2.44 (13) and 74.16 (2)°, respectively. In the crystal, mol-ecules are connected through weak C-H⋯O inter-actions into a hexa-meric unit generating a R 6 (6)(60) motif in the ab plane. The mol-ecules are also connected into C(4) chains through weak C-H⋯N inter-actions. The solvent used to grow the crystal was a mixture of di-chloro-methane and methanol, but the resulting electron density was uninter-pretable. The solvent contribution to the scattering was removed with the SQUEEZE routine in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148-155]. The formula mass and unit-cell characteristics do not take into account the disordered solvent.

2-Amino-5-fluoro-benzoic acid.

In the title compound, C7H6FNO2, the mol-ecule is almost planar (r.m.s. deviation for the non-H atoms = 0.015 Å) and an intra-molecular N-H⋯O hydrogen bond closes an S(6) ring. In the crystal, inversion dimers linked by pairs of O-H⋯O hydrogen bonds generate R2(2)(8) loops. Weak N-H⋯F hydrogen bonds, short F⋯F contacts [2.763 (2) Å] and aromatic π-π stacking inter-actions [centroid-centroid separation = 3.5570 (11) Å] are also observed in the crystal structure.

2-[5-(2-Fluoro-phen-yl)-3-isobutyl-1H-pyrazol-1-yl]benzoic acid.

In the title compound, C(20)H(19)FN(2)O(2), the dihedral angle between the aromatic rings is 62.1 (1)°, and those between the pyrazole ring and the fluoro-benzene and benzoic acid rings are 52.1 (1) and 53.1 (1)°, respectively. In the crystal, mol-ecules are linked into [010] C(7) chains by O-H⋯N hydrogen bonds.

(2,3-Difluoro-phen-yl)(4-tosyl-piperazin-1-yl)methanone.

In the title compound, C(18)H(18)F(2)N(2)O(3)S, the piperazine ring adopts a chair conformation. The dihedral angle between the sulfonyl-bound benzene ring and the best fit plane throught the six non-H atoms of the piperazine ring is 69.4 (2)°, while those between the fluoro-benzene and sulfonyl rings and the fluoro-benzene and piperazine rings are 30.97 (2) and 75.98 (2)°, respectively. In the crystal, mol-ecules are connected to form a tetra-meric unit through C-H⋯O hydrogen bonds. The structure is further stabilized by weak inter-molecular C-H⋯F inter-actions, generating C(8) and C(7) chains running along [100].

4-Methyl-6-(piperidin-1-yl)pyrimidin-2-amine.

The title compound, C(10)H(16)N(4), crystalizes with two mol-ecules (A and B) in the asymmetric unit in which the dihedral angles between the piperidine and pyrimidine rings are 47.5 (1) and 10.3 (1)°. The four C atoms of the pyrimidine ring in one of the mol-ecules are disordered over two sets of sites with occupancy factors 0.508 (11):0.492 (11). In the crystal, the A mol-ecules are linked to one another through N-H⋯N hydrogen bonds, generating R(2) (2)(8) ring patterns and forming inversion dimers. These dimers are further connected on either side to a B molecule through pairs of N-H⋯N hydrogen bonds, resulting in a tetra-meric unit.

1-Tosyl-4-[2-(trifluoro-meth-yl)benz-yl]piperazine.

In the crystal structure of the title compound, C(19)H(21)F(3)N(2)O(2)S, the piperazine ring adopts a chair conformation. The dihedral angles between the mean plane of the piperazine ring and the tosyl and trifluoro-methyl-phenyl rings are 74.52 (3) and 68.30 (2)°, respectively. The sulfonamide N atom deviates from the plane defined by the three attached atoms by 0.327 (1) Å. The crystal structure is stabilized by weak C-H⋯π inter-actions.

(E)-tert-Butyl 4-(N'-hy-droxy-carbam--imid-o-yl)piperazine-1-carboxyl-ate.

In the title compound, C10H20N4O3, the piperazine ring adopts a chair conformation. The mol-ecule adopts an E conformation across the C=N double bond, with the -OH group and the piperazine ring trans to one another. Further, the H atom of the hy-droxy group is directed away from the NH2 group. An intra-molecular N-H⋯O contact occurs involving the NH2 group and the oxime O atom. In the crystal, mol-ecules are linked via strong N-H⋯O and O-H⋯N hydrogen bonds with alternating R2(2)(6) and C(9) motifs into tetra-meric units forming R4(4)(28) motifs.

6-[4-Chloro-2-(trifluoro-meth-yl)phen-yl]-3-fluoro-2-methyl-pyridine.

In the title compound, C13H8ClF4N, the dihedral angle between the benzene and pyridine rings is 59.8 (3)°. In the crystal, mol-ecules are stacked in columns along the b axis through weak C-H⋯π inter-actions.

1-(2-Amino-6-methyl-pyrimidin-4-yl)-N,N-dimethyl-piperidin-4-aminium chloride.

In the title mol-ecular salt, C12H22N5(+)·Cl(-), the cation is protonated at the dimethyl-substituted tertiary N atom. The piperidine ring adopts a chair conformation with the exocyclic N-C bond in an equatorial orientation. The dihedral angle between the piperidine ring (all atoms) and the pyrimidine ring is 14.00 (1)°. In the crystal, the ions are connected by N-H⋯N hydrogen bonds, forming inversion dimers, which are further connected by N-H⋯Cl hydrogen bonds. Aromatic π-π stacking inter-actions [centroid-centroid separation = 3.4790 (9) Å] are also observed in the structure.

(E)-3-Chloro-N'-hy-droxy-benzene-1-carboximidamide.

The title compound, C7H7ClN2O, crystallizes with two independent mol-ecules in the asymmetric unit. The compound adopts an E configuration across the C=N double bond, as the -OH group and the benzene ring are on opposite sides of the double bond while the H atom of the hy-droxy group is directed away from the -NH2 group. In the crystal, mol-ecules are linked to one another through O-H⋯N and N-H⋯O hydrogen bonds, forming chains along [010].

4-Methyl-2,6-bis-(pyrrolidin-1-yl)pyrimidine.

In the crystal of the title compound, C13H20N4, the mol-ecule is nearly planar, the dihedral angles between the pyrimidine and the two pyrrolidine rings being 4.71 (2) and 4.50 (2)°. The crystal features inversion-related dimers linked by pairs of C-H⋯N hydrogen bonds generating R2(2)(16) patterns. The dimeric units are further linked into C(6) chains via an additional C-H⋯N hydrogen bond.