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).

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.

Benzyl N-{2-[5-(4-chloro-phen-yl)-1,2,4-oxadiazol-3-yl]propan-2-yl}carbamate.

In the title 1,2,4-oxadiazole derivative, C(19)H(18)ClN(3)O(3), the 1,2,4-oxadiazole ring makes dihedral angles of 12.83 (8) and 4.89 (8)°, respectively, with the benzyl and 4-chloro-phenyl rings, while the dihedral angle between the benzyl and 4-chloro-phenyl rings is 11.53 (7)°. In the crystal, mol-ecules are linked by N-H⋯N hydrogen bonds into helical chains along the b axis. A weak C-H⋯π inter-action is also present.

1-{4-Chloro-2-[2-(2-fluoro-phen-yl)-1,3-dithio-lan-2-yl]phen-yl}-2-methyl-1H-imidazole-5-carbaldehyde.

There are two mol-ecules in the asymmetric unit of the title imidazole derivative, C(20)H(16)ClFN(2)OS(2). In one mol-ecule, the dithiol-ane ring is disordered over two positions in a 0.849 (9):0.151 (10) ratio. The imidazole ring makes dihedral angles of 79.56 (9) and 18.45 (9)° with the 4-chloro-phenyl and 2-fluoro-phenyl rings, respectively, in one mol-ecule; in the other mol-ecule, the corresponding angles are 82.72 (9) and 17.39 (10)°. In the crystal, mol-ecules are linked by weak C-H⋯O inter-actions and these linked mol-ecules are stacked along the b axis by π-π inter-actions with a centroid-centroid distance of 3.4922 (11) Å. In addition, π-π inter-actions between the imidazole and 2-fluoro-phenyl rings are also observed, with centroid-centroid distances of 3.4867 (11) and 3.4326 (10) Å. The crystal is further consolidated by weak C-H⋯π inter-actions. Cl⋯S [3.5185 (8) Å], C⋯O [3.192 (3) Å] and C⋯C [3.326 (2)-3.393 (3) Å] short contacts are also observed.

N'-(4-Fluoro-benzyl-idene)-2-(4-fluoro-phen-yl)acetohydrazide.

In the title compound, C(15)H(12)F(2)N(2)O, the dihedral angle between the two benzene rings is 48.73 (8)°. The hydrazine group is twisted slightly, with a C-N-N-C torsion angle of 172.48 (12)°. In the crystal, mol-ecules are connected by strong N-H⋯O and weak C-H⋯O hydrogen bonds, forming supra-molecular chains along the c axis. The structure is consolidated by π-π [centroid-centroid separation = 3.6579 (10) Å] and C-H⋯π inter-actions.

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.

1-{1-[2,8-Bis(trifluoro-meth-yl)-4-quin-olyl]-5-methyl-1H-1,2,3-triazol-4-yl}ethanone.

There are two independent mol-ecules in the asymmetric unit of the title compound, C(16)H(10)F(6)N(4)O. The triazole ring is not coplanar with the quinoline ring system; the dihedral angle between the two planes being 74.47 (12) and 63.97 (13)° in the two mol-ecules. The crystal structure is characterized by inter-molecular C-H⋯F, C-H⋯N and C-H⋯O hydrogen bonding. Weak intra-molecular C-H⋯F inter-actions are observed. Disorder is observed in two F atoms of one of the trifluoro-methyl groups of one independent mol-ecule [occupancy ratios 0.77 (3):0.23 (3) and 0.77 (4):0.23 (4)] and in all three F atoms of one of the trifluoro-methyl groups of the second independent mol-ecule [occupancy ratios 0.520 (14):0.480 (14), 0.615 (17):0.385 (17) and 0.783 (11):0.217 (11)]. The O atom is also disordered over two positions with occupancies of 0.60 (13) and 0.40 (13) in the first mol-ecule.

2-{[(E)-2-Hy-droxy-benzyl-idene]amino}-1H-isoindole-1,3(2H)-dione.

In the title compound, C(15)H(10)N(2)O(3), the isoindoline ring system is almost planar [maximum deviation = 0.020 (2) Å] and makes a dihedral angle of 1.57 (7)° with the benzene ring. Intra-molecular O-H⋯N and C-H⋯O hydrogen bonds are observed.

Facile synthesis, cytotoxic and antimicrobial activity studies of a new group of 6-aryl-3-[4-(methylsulfonyl)benzyl]-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines.

The reaction of 4-(methylsulfonyl)phenylacetohydrazide (3) with carbon disulfide and potassium hydroxide followed by hydrazine hydrate gave 4-amino-5-[4-(methylsulfonyl)benzyl]-4H-[1,2,4]triazole-3-thione (4). The resulting triazole was subjected to cyclocondensation reaction with different phenacyl bromides to afford 6-substituted-3-[4-(methylsulfonyl)benzyl]-7H-[1,2,4]triazolo[3,4-b][1,3,4]thiadiazines (5a-i). All structures of the newly synthesized compounds were confirmed by IR, NMR, mass spectral studies and elemental analyses. The newly synthesized compounds were screened for their cytotoxic, antibacterial and antifungal activity. Some of the derivatives have exhibited promising biological activity.

Facile synthesis, characterization and pharmacological activities of 3,6-disubstituted 1,2,4-triazolo[3,4-b][1,3,4]thiadiazoles and 5,6-dihydro-3,6-disubstituted-1,2,4-triazolo[3,4-b][1,3,4]thiadiazoles.

Two new series of compounds namely, 3,6-disubstituted-1,2,4-triazolo[3,4-b][1,3,4]thiadizoles (5a-j) and 5,6-dihydro-3,6-disubstituted-1,2,4-triazolo[3,4-b][1,3,4]thiadizoles (7a-j) were prepared. In continuation of a previously reported study, the first series (5a-j) were synthesized by the cyclocondensation of 4-amino-5-(2-bromo-5-methoxyphenyl)-2,4-dihydro-3H-1,2,4-triazole-3-thione (4) with various substituted aromatic carboxylic acids in phosphorus oxychloride and the second series (7a-j) by the reaction of (4) with various substituted aromatic aldehydes in the presence of p-Toluene sulfonic acid. Reaction of (4) with the aldehyde (9) afforded the Schiff's base (10) and not the cyclised product (11) on treatment with p-Toluene sulfonic acid. Synthesized compounds were structurally confirmed by spectral analysis and studied for their anti-inflammatory, analgesic, anti-oxidant and antimicrobial activities. Some of the tested compounds showed significant pharmacological activities.

Synthesis and antimicrobial activity of 1,2,3-triazoles containing quinoline moiety.

A new series of substituted 1,2,3-triazoles (4a-n) were synthesized from 4-azido-2,8-bistrifluoromethylquinoline 2. The 1,3-dipolar cycloaddition reaction of 2 with ethyl acetoacetate afforded 1-(2,8-Bistrifluoromethylquinolin-4-yl)-5-methyl-1,2,3-triazole-4-carboxylic acid 3, which was then converted into its corresponding acid hydrazide 3a. Condensation of this hydrazide with different aromatic aldehydes resulted in the formation of Schiff's bases, N-[1-Arylmethylene]-1-[2,8-bistrifluoromethylquinoline-4-yl]-5-methyl-1H-1,2,3-triazole-4-carbohydrazides (4a-n). These newly synthesized 1,2,3-triazole derivatives were characterized by analytical and spectral data. All the synthesized compounds were evaluated in vitro for their antibacterial and antifungal activity. A brief investigation of the structure activity relationships revealed that the nature of the substituent on position 4 of the triazole ring influences the antimicrobial activity. Among the newly synthesized compounds, the most active compound was 4n, which contained the 3-methylthien-2-yl moiety and showed a broad spectrum of antimicrobial activity against all the strains used for testing. Compounds 4b, 4c, 4e, 4f, 4h and 4l showed significant antimicrobial activity at the concentration of 6.25 µg/mL.