Synthesis, Characterization and Biological Evaluation of Mononuclear Dichloro-bis[2-(2-chloro-6,7-substituted Quinolin-3-yl)-1H-benzo[d]imidazole]Co(II) Complexes

A series of Co(II) complexes 3¢a-g of 2-(2-chloro-6,7-substituted quinolin-3-yl)-1H-benzo[d]imidazole ligands 3a-g were prepared and characterized by various spectroscopic and physico-chemical methods viz. FT-IR, ESI mass, 1H NMR, 13C NMR and UV-Visible spectroscopy, Thermogravimetric analysis, Magnetic susceptibility, Molar conductance and Elemental analysis. The 2-(2-chloro-6,7-substituted quinolin-3-yl)-1H-benzo[d]imidazole ligands 3a-g have been synthesized by cyclocondensation of benzene-1,2-diamine with 2-chloroquinoline-3-carbaldehydes by using ceric ammonium nitrate as a catalyst in presence of hydrogen peroxide as an oxidant. The structures of all ligands were confirmed by IR, Mass, UV-Visible, 1H NMR and 13C NMR spectroscopy. All ligands 3a-g and their Co(II) complexes 3¢a-g were screened for their in vitro antimicrobial activity using twofold serial dilution technique against standard MTCC strains of two Gram-positive Staphylococcus aureus and Streptococcus pyogenes, two Gram-negative Escherichia coli and Pseudomonas aeruginosa bacteria and three Candida albicans, Aspergillus niger and Aspergillus clavatus fungus in comparison with standard drugs. All ligands 3a-g and complexes 3¢a-g also evaluated for antimycobacterial activity against standard Mycobacterium tuberculosis H37Rv strain. DOI: http://dx.doi.org/10.17807/orbital.v7i2.53

Microwave assisted solid phase catalyst-free Biginelli synthesis of 3,4-dihydropyrimidin-2(1<i>H</i>)-one and 3,4-dihydropyrimidin-2(1<i>H</i>)-thione: A green approach, characterization and molecular crystal structures

<p>Solid phase catalyst-free Biginelli synthesis of novel 5-carbethoxy-4-(3-bromo-4-hydroxy-5-methoxyphenyl)-6-methyl-3,4-dihydropyrimidin-2(1H)-one (C₁₅H₁₇BrN₂O₅) and 5-carbethoxy-4-(3-bromo-4-hydroxy-5-methoxyphenyl)-6-methyl-3,4-dihydropyrimidin-2(1H)-thione (C₁₅H₁₇BrN₂O₄S) has been carried out under microwave irradiation at 400W. The structures of both compounds were confirmed by ¹H NMR, ¹³C NMR, Mass, FT-IR, Elemental analysis, and single crystal X-ray diffraction method. The single crystals of both compounds were obtained by crystallization in 0.35 × 0.30 × 0.25 mm dimension for (C₁₅H₁₇BrN₂O₅) and 0.35 × 0.32 × 0.30 mm dimension for (C₁₅H₁₇BrN₂O₄S). Both compounds, (C₁₅H₁₇BrN₂O₅) and (C₁₅H₁₇BrN₂O₄S) crystallizes in the monoclinic P2₁/c space group and shows four and two intermolecular hydrogen bonds, respectively.</p