Synthesis of substituted flavone derivatives as potent antimicrobial agents

The biological activity of flavone has been enhanced by introducing heteroaryl moiety in C-2 position of chromone derivatives. Thus, 2-(1H-Indol-3-yl)-4H-chromen-4-one derivatives (6a-e) and 2-(2-chloroquinolin-3-yl)-4H-chromen-4-one derivatives (7a-e) were synthesized from corresponding chalcone. They were structurally confirmed by analytical and spectral data and evaluated for their antimicrobial activities. The results showed that this skeletal framework exhibited marked potency as antimicrobial agents.KEY WORDS: Chalcone, Flavone, Chromone, Antibacterial activity, Antifungal activity Bull. Chem. Soc. Ethiop. 2011, 25(3), 419-425

Effect of solvent change on chemical shifts of 4-benzyl-4-hydroxypiperidines

4-Benzyl-4-hydroxypiperidines 1-8 have been synthesized through Mannich reaction and were characterized through high resolution 1H and 13C NMR spectra in CDCl3.The conformational studies of the above eight compounds have been thoroughly done by using proton and 13C spectral data and the assigned conformations were also supported by Hybrid HF/DFT B3LYP/6-3G* calculations. These results are published earlier by us. In order to study the effect of solvent on the chemical shifts of these piperidines, 1H NMR spectra were recorded in C6D6 and DMSO-d6. The effect of change of solvents results appreciable change in the chemical shifts of various protons in the title compounds

Synthesis, Spectral Characterization And Pharmacological Significance of Fe(III) Complex With Schiff Base and Thiocyanate ION as Ligands

A novel Fe(III) complex of Schiff’s base derived from phenylacetylurea condensed with salicylaldehyde (SBPS) and thiocyanate(SCN-) ion was synthesized by using microwave irradiation. Microwave synthesis gives high yield of the complex within a short time. The molecular formula and the probable geometry of the complex have been deduced from elemental analysis, molar conductance, UV, FT-IR, and Far IR spectra. The molar conductance indicates that the Fe(III) complex is a non-electrolyte. FT-IR spectra show that Schiff’s base and thiocyanate ion are coordinated to the metal ion in a monodentate manner. The electronic spectrum and the magnetic moment indicate the geometry of the complex is found to be distorted octahedral. The antimicrobial activities of ligands and their Fe(III) complex were studied against the few microorganisms by agar - well diffusion method. The complex shows moderate activity against the bacteria and enhanced activity against the fungi as compared to the SBPS ligand. &nbsp

Synthesis of Substituted 3,4-Dialkyl-2,6-Diaryl-Piperidin-4-ol Derivatives and Their Conformational Study

The synthesis of series of 3,4-dialkyl-2,6-diaryl-piperidin-4-ol derivatives (7-12) by reduction of cis-3-alkyl-2,6-diarylpiperidin-4-one (1-6) using Grignard reagent has been reported. The synthesized heterocycles have been characterized on basis of spectroscopic data and their conformation has also been discussed

Conformational studies of some N-acyl-t(3)-isopropyl-r(2), c(6)-bis-(2'-furyl)piperidin-4-ones

160-169The high resolution ¹H and ¹³C NMR spectra of four N-acyl-t(3)-isopropyl-r(2),c(6)-bis(2¢-furyl)piperidin-4-ones 1-4 have been recorded at various temperatures and analysed. The spectra reveal the presence of two rotameric forms (E and Z) in solution. ¹H-¹H COSY spectra for 1-4 and ¹H-¹³C COSY spectrum for 4 have been recorded to assist the assignment of the signals for the E and Z isomers of 1-4. Coupling constants predict an equilibrium mixture of boat form B₁ and alternate chair form CA for 1-4. The effect of varying the substituents at nitrogen on the ¹H and ¹³C chemical shifts have been analysed in detail. Mass spectra have also been recorded for 1-5