2-[4-(Methyl-sulfon-yl)phen-yl]acetonitrile.

In the title compound, C(9)H(9)NO(2)S, the benzene ring and the acetonitrile group are approximately coplanar, with a C-C-C-C torsion angle of 1.1 (3)° between them. In the crystal, mol-ecules are linked via inter-molecular C-H⋯O hydrogen bonds into layers parallel to (001).

(E)-3-(4-Chloro-phen-yl)-1-(2,3,4-trichloro-phen-yl)prop-2-en-1-one.

In the title chalcone derivative, C(15)H(8)Cl(4)O, the C=C double bond exists in an E configuration and the dihedral angle between the two benzene rings is 48.13 (11)°. In the crystal, mol-ecules are arranged into columns and stacked down the a axis featuring possible weak aromatic π-π stacking inter-actions [centroid-centroid separation = 3.888 (2) Å].

2-Isobutyl-6-phenyl-imidazo[2,1-b][1,3,4]thia-diazole.

In the title compound, C(14)H(15)N(3)S, the imidazo[2,1-b][1,3,4]thia-diazole fused-ring system is close to planar, with a maximum deviation of 0.042 (1) Å, and the dihedral angle between it and the phenyl ring is 24.21 (6)°. The isobutyl group is disordered over two sets of sites in a 0.899 (9):0.101 (9) ratio. In the crystal, weak aromatic π-π stacking inter-actions involving the imidazole and thia-diazole rings with a centroid-centroid distance of 3.8067 (7) Šoccur.

2-Isobutyl-6-(4-meth-oxy-phen-yl)imidazo[2,1-b][1,3,4]thia-diazole.

In the title compound, C(15)H(17)N(3)OS, the dihedral angle between the statistically planar imidazo[2,1-b][1,3,4]thia-dia-zole fused-ring system (r.m.s. deviation = 0.002 Å) and the methyoxbenzene ring is 4.52 (6)°. In the crystal, mol-ecules are arranged into columns and stacked down the a axis. The crystal structure is stabilized by weak C-H⋯π and π-π inter-actions [centroid-centroid separations = 3.6053 (8) and 3.7088 (7) Å].

Methyl 2-[2-(benzyl-oxycarbonyl-amino)-propan-2-yl]-5-hy-droxy-6-meth-oxy-pyrimidine-4-carboxyl-ate.

In the title compound, C(18)H(21)N(3)O(6), a pyrimidine derivative, the dihedral angle between the benzene and pyrimidine rings is 52.26 (12)°. The carboxyl-ate unit is twisted with respect to the pyrimidine ring, making a dihedral angle of 12.33 (7)°. In the crystal, mol-ecules are linked by a pair of O-H⋯O hydrogen bonds, forming an inversion dimer. The dimers are stacked into columns along the b axis through weak C-H⋯O inter-actions.

(E)-1-(3,4-Dimeth-oxy-phen-yl)-3-[4-(methyl-sulfan-yl)phen-yl]prop-2-en-1-one.

In the title compound, C(18)H(18)O(3)S, the C=C double bond exists in an E configuration and the dihedral angle between the two benzene rings is 11.74 (8)°. In the crystal, mol-ecules are linked into a three-dimensional network by C-H⋯O hydrogen bonds. The crystal structure is also stabilized by weak C-H⋯π inter-actions.

(5E)-5-(4-Meth-oxy-benzyl-idene)-2-(piperidin-1-yl)-1,3-thia-zol-4(5H)-one.

In the title compound, C(16)H(18)N(2)O(2)S, the piperidine ring adopts a chair conformation. The central 4-thia-zolidinone ring makes dihedral angles of 12.01 (7) and 51.42 (9)°, respectively, with the benzene ring and the least-squares plane of the piperidine ring. An intra-molecular C-H⋯S hydrogen bond stabilizes the mol-ecular structure and generates an S(6) ring motif. In the crystal, mol-ecules are linked into a tape along the c axis by inter-molecular C-H⋯O hydrogen bonds.

N-[(E)-4-Chloro-benzyl-idene]-2,4-dimethyl-aniline.

The title mol-ecule, C(15)H(14)ClN, exists in a trans configuration with respect to the C=N bond [1.2813 (16) Å]. The dihedral angle between the benzene rings is 52.91 (6)°. The crystal structure is stabilized by weak inter-molecular C-H⋯π inter-actions.

3-{1-[4-(2-Methyl-prop-yl)phen-yl]eth-yl}-4-phenyl-1H-1,2,4-triazole-5(4H)-thione.

In the title compound, C(20)H(23)N(3)S, the central 1,2,4-triazole ring makes dihedral angles of 69.76 (9) and 81.69 (8)°, respectively, with the phenyl and benzene rings. In the crystal, mol-ecules are linked into a centrosymmetric dimer by a pair of inter-molecular N-H⋯S hydrogen bonds, generating an R(2) (2)(8) ring motif.

N-(2-Chloro-phen-yl)-2-({5-[4-(methyl-sulfan-yl)benz-yl]-4-phenyl-4H-1,2,4-triazol-3-yl}sulfan-yl)acetamide.

In the title mol-ecule, C(24)H(21)ClN(4)OS(2), the central 1,2,4-triazole ring forms dihedral angles of 89.05 (9), 86.66 (9) and 82.70 (10)° with the chloro-substituted benzene ring, the methyl-sulfanyl-substituted benzene ring and the phenyl ring, respectively. In the crystal, mol-ecules are linked into sheets parallel to (100) by inter-molecular N-H⋯N and weak C-H⋯O hydrogen bonds.

N'-(4-Chloro-benzyl-idene)-2-[4-(methyl-sulfan-yl)phen-yl]acetohydrazide.

In the title compound, C(16)H(15)ClN(2)OS, the hydrazine group is twisted slightly: the C-N-N-C torsion angle is 175.46 (13)°. The dihedral angle between the two terminal aromatic rings is 87.01 (8)°. In the crystal, inversion dimers linked by pairs of N-H⋯O hydrogen bonds generate R(2) (2)(8) loops. The dimers are further linked by weak C-H⋯π inter-actions.

(5E)-5-(2,4-Dichloro-benzyl-idene)-2-(piperidin-1-yl)-1,3-thia-zol-4(5H)-one.

In the title compound, C(15)H(14)Cl(2)N(2)OS, the piperidine ring adopts a chair conformation. The dihedral angle between the thia-zolidine ring and the dichloro-benzene ring is 9.30 (4)°; this near coplanar conformation is stabilized by the formation of an intra-molecular C-H⋯S hydrogen bond, which generates an S(6) ring. In the crystal, mol-ecules are linked by C-H⋯O hydrogen bonds, forming [001] chains. Weak π-π inter-actions [centroid-centroid separation = 3.5460 (5) Å] consolidate the structure.

2-Methyl-6-(trifluoro-meth-yl)imidazo[1,2-a]pyridine-3-carbonitrile.

In the title compound, C(10)H(6)F(3)N(3), the imidazo[1,2-a]pyridine group is essentially planar with a maximum deviation of 0.021 (1) Å. The F atoms in the trifluoro-methyl group and the methyl H atoms are each disordered over two sets of sites with refined site occupancies of 0.68 (1):0.32 (1). In the crystal, mol-ecules are linked into infinite chains through two C-H⋯N inter-actions forming R(2) (2)(12) and R(2) (2)(8) hydrogen-bond ring motifs. These chains are stacked along the a axis.

6-(4-Chloro-phen-yl)-2-isobutyl-imidazo[2,1-b][1,3,4]thia-diazole.

In the title compound, C(14)H(14)ClN(3)S, the imidazo[2,1-b][1,3,4]thia-diazole system is essentially planar, with a maximum deviation of 0.006 (2) Å. The dihedral angle between the imidazo[2,1-b][1,3,4]thia-diazole and chloro-phenyl rings is 5.07 (8)°. In the crystal, there are no classical hydrogen bonds but stabilization is provided by weak π-π [centroid-centroid distance = 3.5697 (11) Å] and C-H⋯π inter-actions.

Design and Microwave Assisted Synthesis of Coumarin Derivatives as PDE Inhibitors.

Coumarins appended to benzimidazole through pyrazole are designed and synthesized using microwave irradiation. These compounds were analyzed for phosphodiesterase (PDE) inhibition indirectly by motility pattern in human spermatozoa. Some of the synthesized compounds, namely, 5d, 5e, 5f, 5g, 5h, and 5k, have exhibited potent inhibitory activity on PDE.

Synthesis and antimicrobial activities of some new triazolothiadiazoles bearing 4-methylthiobenzyl moiety.

A series of substituted triazolothiadiazoles have been synthesized by condensing 4-amino-3-[4-methylthiobenzyl]-4H-1,2,4-triazole-5-thiol (5) with substituted aryl furoic acids/aromatic acids in the presence of POCl3. The triazole (5) was obtained by the fusion of 4-methylthiophenyl acetic acid with thiocarbohydrazide. The structures of newly synthesized compounds are characterized by elemental analysis, IR, 1H NMR and mass spectroscopic studies and were screened for their antimicrobial activities. The preliminary results revealed that some of the compounds exhibited promising antimicrobial activities.

Synthesis and antitumor activity studies of some new fused 1,2,4-triazole derivatives carrying 2,4-dichloro-5-fluorophenyl moiety.

A series of 3-(2,4-dichloro-5-fluorophenyl)-6-(substituted phenyl)-1,2,4-triazolo[3,4-b]-1,3,4-thiadiazines (4) (Fig. 1) have been synthesized by the cyclization of 3-(2,4-dichloro-5-fluorophenyl)-1,2,4-triazol-5-thiol (3) with substituted phenacyl bromides. All the newly synthesized compounds were confirmed by IR, (1)H NMR and mass spectral studies. Among the compounds tested for their antitumor activity three compounds exhibited in vitro antitumor activity with moderate to excellent growth inhibition against a panel of sixty cancer cell lines of leukemia, non-small cell lung cancer, melanoma, ovarian cancer, prostate and breast cancer. The compound 4d showed promising antiproliferative activity with GI(50) values in the range of 1.06-25.4 microM.