Reactions between arylhydrazinium chlorides and 2-chloroquinoline-3-carbaldehydes: molecular and supramolecular structures of a hydrazone, a 4,9-dihydro-1H-pyrazolo[3,4-b]quinoline and two 1H-pyrazolo[3,4-b]quinolines.

Hydrazone derivatives exhibit a wide range of biological activities, while pyrazolo[3,4-b]quinoline derivatives, on the other hand, exhibit both antimicrobial and antiviral activity, so that all new derivatives in these chemical classes are potentially of value. Dry grinding of a mixture of 2-chloroquinoline-3-carbaldehyde and 4-methylphenylhydrazinium chloride gives (E)-1-[(2-chloroquinolin-3-yl)methylidene]-2-(4-methylphenyl)hydrazine, C17H14ClN3, (I), while the same regents in methanol in the presence of sodium cyanoborohydride give 1-(4-methylphenyl)-4,9-dihydro-1H-pyrazolo[3,4-b]quinoline, C17H15N3, (II). The reactions between phenylhydrazinium chloride and either 2-chloroquinoline-3-carbaldehyde or 2-chloro-6-methylquinoline-3-carbaldehyde give, respectively, 1-phenyl-1H-pyrazolo[3,4-b]quinoline, C16H11N3, (III), which crystallizes in the space group Pbcn as a nonmerohedral twin having Z' = 3, or 6-methyl-1-phenyl-1H-pyrazolo[3,4-b]quinoline, C17H13N3, (IV), which crystallizes in the space group R\overline{3}. The molecules of compound (I) are linked into sheets by a combination of N-H...N and C-H...π(arene) hydrogen bonds, and the molecules of compound (II) are linked by a combination of N-H...N and C-H...π(arene) hydrogen bonds to form a chain of rings. In the structure of compound (III), one of the three independent molecules forms chains generated by C-H...π(arene) hydrogen bonds, with a second type of molecule linked to the chains by a second C-H...π(arene) hydrogen bond and the third type of molecule linked to the chain by multiple π-π stacking interactions. A single C-H...π(arene) hydrogen bond links the molecules of compound (IV) into cyclic centrosymmetric hexamers having \overline{3} (S6) symmetry, which are themselves linked into a three-dimensional array by π-π stacking interactions.

Synthesis, molecular docking and anti-mycobacterial evaluation of new imidazo[1,2-a]pyridine-2-carboxamide derivatives.

New anti-tubercular agents, imidazo[1,2-a]pyridine-2-carboxamide derivatives (5a-q) have been designed and synthesized. The structural considerations of the designed molecules were further supported by the docking study with a long-chain enoyl-acyl carrier protein reductase (InhA). The chemical structures of the new compounds were characterized by IR, (1)H NMR, (13)C NMR, HRMS and elemental analysis. In addition, single crystal X-ray diffraction has also been recorded for compound 5f. Compounds were evaluated in vitro against Mycobacterium tuberculosis H37Rv, and cytotoxicity against HEK-293T cell line. Amongst the tested compounds 5j, 5l and 5q were emerged as good anti-tubercular agents with low cytotoxicity. The structure-anti TB activity relationship of these derivatives was explained by molecular docking.

New polyfunctional imidazo[4,5-C]pyridine motifs: synthesis, crystal studies, docking studies and antimicrobial evaluation.

New antimicrobial agents, imidazo[4,5-c]pyridine derivatives have been synthesized. We have developed a new synthetic protocol for the final reaction, an efficient microwave-assisted synthesis of imidazo[4,5-c]pyridines from substituted 3,4-diaminopyridine and carboxylic acids in presence of DBU mediated by T3P. The chemical structures of the new compounds were characterized by IR, (1)H NMR, (13)C NMR, mass spectral analysis and elemental analysis. In addition, single crystal X-ray diffraction has also been recorded for compound 9c. The in vitro antimicrobial activities of the compounds were conducted against various Gram-negative, Gram-positive bacteria and fungi. Amongst the tested compounds 9c, 9e, 9g, 9k and 9l displayed promising antimicrobial activity. The molecular docking of GlcN-6-P synthase with newly synthesized compounds was carried out.

5,7-syn-Bis(trimethylsilyl)-5-norbornene-2,3-endo-dicarboxylic acid: a rare co-existence of dimeric and catemeric synthons.

The crystal and molecular structure of the title compound, C(15)H(26)O(4)Si(2), reveals a self-assembly facilitated via the rare co-existence of dimeric and catemeric patterns, which is attributed to the influence of the trimethylsilyl groups. The structure is dicussed in the context of a database search and subsequent analysis of structures of cis-1,2-dicarboxylic acids.