Potassium Bis(2-[α-Hydroxyalkyl/Aryl] Benzimidazolato) Dioxovanadates(V) through Base Assisted Aerial Oxidation of the Corresponding Oxovanadium(IV) Complexes

2002 ◽  
Vol 2002 (6) ◽  
pp. 260-261 ◽  
Author(s):  
Mannar R. Maurya ◽  
Shilpa Khurana

Bis(2-[α-hydroxyalkyl/aryl]benzimidazolato)dioxovanadates(V) dihydrates, as their potassium salts, were prepared by the reaction of [VO(acac)2] with the respective benzimidazole followed by aerial oxidation in presence of KOH. An octahedral structure has been proposed for these complexes on the basis of IR, electronic and 1H NMR spectral studies, and thermogravimetric analysis.

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
S. Nagashree ◽  
P. Mallu ◽  
L. Mallesha ◽  
S. Bindya

A series of methyl-2-aminopyridine-4-carboxylate derivatives,3a–f,were synthesized in order to determine theirin vitroantimicrobial activity. The chemical structures of the synthesized compounds were confirmed by elemental analyses, FT-IR, and1H NMR spectral studies. Among the synthesized compounds,3cand3dshowed good antimicrobial activity compared to other compounds in the series.


2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Pawan P. Kalbende ◽  
Mangesh V. Tarase ◽  
Anil B. Zade

Polycondensation reaction was employed to synthesize a new copolymer resin (p-NP-4,4′-MDA-F) from p-nitrophenol (p-NP) and 4,4′-methylene dianiline (4,4′-MDA) with formaldehyde (F) in presence of 2 M hydrochloric acid as a catalyst at130±1°C. The resin was characterized by elemental analysis and spectral studies such as UV-visible, FT-IR, and1H-NMR spectra which were used to confine the most probable structure of synthesized copolymer. Thermal degradation pattern and kinetics have been investigated by thermogravimetric analysis. Thermal degradation curve have been studied with minute detail for each degradation step. Friedman, Chang, Sharp-Wentworth, Freeman-Carroll, and Coat-Redfern methods have been implemented in order to compute the kinetic parameters, that is, thermal activation energy (Ea), order of reaction (n), and frequency factor (z).


2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
M. K. Prashanth ◽  
M. Madaiah ◽  
H. D. Revanasiddappa ◽  
K. N. Amruthesh

Condensation of amine 1 with aldehyde 2 gives Schiff base, N-(4-((benzofuran-2-ylmethylene) amino)phenyl)acetamide 3. Schiff base on N-acylation with different substituted acid chlorides in the presence of triethylamine gives the corresponding benzamides, N-acetyl-N-(4-((benzofuran-2-ylmethylene)amino)phenyl)substitutedbenzamide (NABP) 5a–j. The structures of newly synthesized compounds were characterized by elemental analysis, 1H NMR, 13C NMR FT-IR, and mass spectral studies. Compounds 3 and 5a–j have been screened for their antimicrobial activity using the disc diffusion and minimum inhibitory concentration (MIC) method against the selected bacterial and fungal strain. Compounds 5a, 5e, 5g, and 5h were found to be more active against all tested strains. The antioxidant properties were evaluated by 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radical scavenging methods. Compounds 5i and 5j showed predominant antioxidant activities among the synthesized analogues. The interaction between NABP and bovine serum albumin (BSA) was investigated using fluorescence and ultraviolet spectroscopic techniques at 298 K under imitated physiological conditions. The results revealed that NABP caused the fluorescence quenching of BSA through a static quenching procedure. The binding constants and the number of binding sites were calculated. The binding distance between the donor (BSA) and acceptor (NABP) was determined based on Forster’s theory.


2011 ◽  
Vol 6 (9) ◽  
pp. 1934578X1100600
Author(s):  
Alejandro Valdez-Calderón ◽  
J. Martín Torres-Valencia ◽  
J. Jesús Manríquez-Torres ◽  
René Velázquez-Jiménez ◽  
Mario A. Gómez-Hurtado ◽  
...  

The new sesquiterpene (1 R,2 R,3 R,6 R,7 S)-1-acetoxy-2,3-dmydroxy-2,3-dihydrobisabolene (3) together with ten known terpenes and three known flavonoids were isolated from the aerial parts and from the roots of Stevia tomentosa. The structure of 3 follows from spectral studies, the relative chirality at C-3 follows from 1H NMR coupling constants comparison with the corresponding calculated values obtained by applying a generalized Karplus-type relationship to the dihedral angles of model compounds, and the absolute configuration is assumed in analogy to known (2 R,3 R,6 R,7 S)-2,3-epoxy-2,3-dihydrobisabolen-1-one (2).


2014 ◽  
Vol 69 (9-10) ◽  
pp. 969-981 ◽  
Author(s):  
Olcay Bekircan ◽  
Emre Mentese ◽  
Serdar Ulker

Abstract In the present investigation, the key intermediate acetohydrazide derivative 5 was synthesized starting from 3-(4-methoxybenzyl)-4-amino-4,5-dihydro-1,2,4-triazol-5-one (1) by a four-step reaction. Thiosemicarbazides 6a-f and arylidenehydrazide derivatives 8a-d were obtained from compound 5. The cyclization of compounds 6a-f in the presence of NaOH resulted in the formation of compounds 7a-f. The compounds were characterized by IR, 1H NMR, 13C NMR spectroscopy, elemental analysis and mass spectral studies. The compounds were tested for their anti-lipase, anti-α-glucosidase and anti-mycobacterial activities. Compounds 6b and 8c exhibited excellent anti-lipase activity, and compound 8d showed excellent anti-a-glucosidase activity. Compounds 3 and 4 exhibited good antituberculosis activity


2013 ◽  
Vol 2013 ◽  
pp. 1-12
Author(s):  
Hoda A. Bayoumi

Preparation and chemical analysis of Mn(II), Fe(III), Co(II), Ni(II), and Zn(II) complexes with Schiff base L [o-HOC6H4CH:N(CH2)6N:CHC6H4OH-o] are the main tasks of this work. The octahedral (M2L2·nH2O·X) complexes in 1 : 1 M : L ratio (X = NO3− or Ac− group, L = ligand) were prepared by involving the hydroxylic group in ortho position. All complexes were characterized on the basis of elemental analysis, UV, IR, 1H NMR, Gc/Ms, thermogravimetric analysis, magnetic measurements, molar conductance, and electrical conductivity. The obtained data indicate that all the investigated compounds behave as semiconductor materials.


2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Aida L. El-Ansary ◽  
Nora S. Abdel-Kader

The Schiff bases, L1, L2, and L3, are synthesized from the condensation of 5,7-dihydroxy-6-formyl-2-methylbenzopyran-4-one (L) with 2-aminopyridine (1), p-phenylenediamine (2), and o-phenylenediamine (3). The prepared Schiff bases react with lanthanum (III), neodymium (III), and erbium (III) nitrate to give complexes with stoichiometric ratio (1 : 1) (ligand : metal). The binuclear complexes of Er(III) with L3 and the three metal ions with L2 are separated. The complexes have been characterized by elemental analysis, molar conductance, electronic absorption, and infrared, 1H-NMR spectral studies. The presence of hydrated and coordinated water molecules is inferred from thermogravimetric analysis. Thermal degradation studies show that the final product is the metal oxide. The luminescence properties of the Nd(III) and Er(III) complexes in dimethylformamide (DMF) solutions were investigated.


2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Mohammed M. Ansari ◽  
Shirish P. Deshmukh ◽  
Rizwan Khan ◽  
Mohammed Musaddiq

A series of S-benzyl aryl thiourea were condensed with o-Methoxy phenyl isocyanate to yield respective isothiobiuret derivatives. The newly synthesized compounds were characterized by 1H-NMR, IR, and Mass Spectral studies and tested for biological activities.


1993 ◽  
Vol 48 (4) ◽  
pp. 409-417 ◽  
Author(s):  
Rostislav D. Lampeka ◽  
Zamira D. Uzakbergenova ◽  
Victor V. Skopenko

Mixed complexes of Co(III) with 2-oximinopropionic (H2A) or 2-oximino-3-phenylpropionic (H2B) acid and different amine (imidazole, benzimidazole, pyridine, β-picoline, γ-picoline) are reported. Characterization of the complexes was based upon elemental analysis, conductivity and JR, 1H NMR, and electronic absorption spectra, and X-ray diffraction analysis. The organic ligands behave as O,N donors via the carboxyl oxygen and the oxime nitrogen atoms. A trans-octahedral structure has been assigned to the bis(2-oximinocarboxylato)bis(amine)cobalt(III) on the basis of 1H NMR data.The crystal and molecular structures of the complexes trans-[bis(2-oximinopropionato)bis-(imidazole)]- (I) and trans-[bis(2-oximinopropionato)bis(pyridine)]cobalt(III) (II) were determined. I crystallizes in space group P2/n with a = 14.1 67(2), b = 8.774(1), c = 14.785(2) Å,β = 113.37(1)°, Z = 4, Dcalc = 1.568 g · cm-3. II crystallizes in space group P1̄ with a = 9.122(2), b = 10.038(2), c = 11.759(2) Å, α = 69.95(1)°, β = 67.47(2)°, γ = 69.49(2)°, Ζ = 2, Dcalc = 1.547 g cm-3. The structures were refined to unweighted R factors of 0.036 and 0.028, respectively. The coordination sphere around Co is pseudo-octahedral with the 2-oximinopropionato ligands occupying four equatorial positions, and the amines in axial positions.


e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Mehrdad Mahkam ◽  
Bakhshali Massoumi ◽  
Hossien Mirfatahi

AbstractChemical modification of inexpensive commercial polymers, such as styrene, is a safe methodology to obtain new copolymers. The 4-chloromethyl styrene (CMS) was copolymerized with styrene (in various mole ratios) by free radical polymerization method at 70 ºC using α,α-azobis(isobutyronitrile) (AIBN) as an initiator. The azide ion was covalently attached to the obtained copolymers with replacement of all the chlorine atoms in CMS units. The 1,3-dipolar click cycloaddition reaction between azido polymers and dimethyl acetylene dicarboxylate (DMAD) yielded polymers with 1,2,3-triazoles in side chain. The polymers, obtained in quantitative yields, were characterized by FT-IR and 1H NMR spectroscopy; thermogravimetric analysis (TGA) and GPC studies. The thermogravimetric analysis (TGA) indicated that the thermal stability of copolymers increases with incorporation of 1,2,3-triazole groups in side chains of copolymers.


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