Synthesis, characterization and molecular docking studies of some new 1,3,4-oxadiazolines bearing 6-methylpyridine moiety for antimicrobial property.

A new series of 3-acetyl-2-aryl-2H/methyl-5-[3-(6-methylpyridinyl)]-2,3-dihydro-[1,3,4]-oxadiazole derivatives were synthesized from 6-methyl nicotinate through a multistep reaction sequence. The structures of newly synthesized compounds were established on the basis of elemental analysis, IR, 1H NMR, 13C NMR and mass spectral data. Three dimensional structure of the compound 5f was further confirmed by single crystal X-ray analysis.

(2E)-1-[2,3-Dichloro-6-methyl-5-(trifluoro-meth-yl)phen-yl]-2-(1-phenyl-ethyl-idene)hydrazine.

The title compound, C(16)H(13)Cl(2)F(3)N(2), exists in an E conformation with respect to the C=N bond [1.2952 (11) Å] and the C-N-N=C torsion angle is 175.65 (8)°.

1-[2-(4-Chloro-phen-yl)-5-phenyl-2,3-dihydro-1,3,4-oxadiazol-3-yl]ethanone.

In the title compound, C(16)H(14)ClN(3)O(2), the 2,3-dihydro-1,3,4-oxadiazole ring [maximum deviation = 0.030 (1) Å] and the pyridine ring [maximum deviation = 0.012 (1) Å] are inclined slightly to one another, making a dihedral angle of 11.

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.

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.