Journal of Applied Chemical Research
Year:2016 | Volume:10 | Issue:1|Papers Count:12

A water-accelerated multi-component synthesis of organic target molecules was used as a key method for the preparation of cyclopentadiene derivatives. The three-component condensation reactions of primary amines with alkyl propiolates in the presence of N-methylimidazole in water at room temperature were developed as efficient and clean green synthetic procedures for the high-yielding preparation of 4-oxo-2, 5-cyclopentadiene-1, 2-dicarboxylate derivatives.

New tin (IV) complexes of empirical formula, [Cl2Me2Sn (H2L) 1-3], where ((H2L) 1-3: Methyl-2- {[1-methyl-2- (2-hydroxy-3-methoxyphenyl) methylidynenitrilo] ethyl} amino-1-cyclopentenedithiocarboxylate [H2cd3OMesalMeen], Methyl-2- {[1-methyl-2- (2-hydroxy-4-methoxyphenyl) methylidynenitrilo] ethyl} amino-1-cyclopentenedithiocar-boxylate, [H2cd4OMesalMeen], Methyl-2- {[1-methyl-2- (2-hydroxy-5-methoxyphenyl) -methylidynenitrilo] ethyl} amino-1- cyclopentenedithiocarboxylate, H2cd5OMesalMeen]) have been prepared and fully characterized by a variety of physico-chemical techniques. Spectroscopic data suggest that in three complexes the Schiff base ligand is coordinated through oxygen. The Schiff base ligands and their Sn (IV) complexes were tested against two pathogenic bacteria (Staphylococcus aureus as Gram-positive bacteria and Escherichia coli as Gram-negative bacteria). All the complexes exhibit higher antibacterial activity than the free ligands. Computation analyses at the level of DFT with Becke’s three parameter hybrid methods were performed to study the geometrics, electronic structures; HOMO- LUMO energy gap, dipole moment and its calculated vibrational frequencies were investigated. An excellent agreement between the experimental and calculated results obtained from the two spectra methods.

In this research, a metal oxide nanocatalyst of ZnO supported copper oxide is reported as a highly efficient recyclable catalyst for the chemoselective synthesis of 1, 1-diacetates. The catalyst was synthesized by co-precipitation method and characterized by XRD, BET specific surface area, ESEM, EDS and TEM analysis. A wide range of aldehydes, including aromatic and aliphatic aldehydes were converted into the corresponding 1, 1-diacetates. The experimental procedure with CuO-ZnO nanocatalyst is quite straightforward. The catalyst can be recovered by simple filtration and recycled up to 6 consecutive runs without any losing of its efficiency.

Calcium ions have very strong affinity and binds effectively to alizarin red dye during staining of biomaterials. This promotes us to choose calcium hydroxide as a low cost adsorbent for the removal of alizarin red dye. Various parameters such as pH, concentration, dose of adsorbent, time, and temperature have been investigated. In addition, enthalpy, entropy, free energy and activation energy have been estimated. Different types of isotherms have been evaluated to understand the nature adsorption and its kinetics. It has been found that the adsorption equilibrium can be obtained after 120 minutes. The adsorption of alizarin red dye on calcium hydroxide is endothermic in nature and occurs spontaneously. It has been found that the adsorption is effective at pH=12 (60 oC) and the kinetic parameters indicate that the adsorption phenomena is of monolayer type and fits well for the pseudo-second order rate equation.

The 1: 1 reactive intermediates produced in the reaction between alkyl isocyanides and dialkyl acetylenedicarboxylates were trapped with 2-thioxothiazolidin-4-one to generate to highly functionalized ketenimines. A series of new 2-thioxothiazolidin-4-one derivatives were synthesized in moderate yields. The advantages of the present method include good functional group tolerance and simple experimental procedure and purification.

In this study, we used advanced oxidation process (AOP) for the removal of a cationic and anionic blue dyes, namely Basic Blue 3 (BB3) and Acid blue 62 (AB62), from aqueous solutions. Fenton reactions are mixture of H2O2 and Fe2+. However this paper investigates the application of twelve different catalysts such as: FeCl2, FeSO4, (NH4) Fe (SO4)2, FeCl3, Nano iron (Fe0), Fe (NO3)3, K2FeO4, Nano Silver (Ag), Nano ZnO, Zn (NO3)2, Nano Al2O3 and Al2 (SO4)3, with the H2O2. The formed hydroxyl radicals led to the oxidative degradation of BB3& AB62. The results show that the optimum amounts of reagent was 5.6 mg/L as a metal catalyst and 30mM of H2O2 for an initial dye concentration at 50 mg/L. The percentremoval of dye were found to be strongly influenced by the increasing of the oxidant and metal catalyst up to a certain value. It was found that the maximum removal of dye (up to 99.9%.) was enhanced using pH=3.The best catalyst for the decomposition of AB62 dye was FeCl2 and for BB3 dye wasNH4Fe (SO4)2.The correlation coefficient (R2) obtained from first order reaction model were found to be higher than 0.98 for both investigated dyes. Comparing the results shows that the removal of AB62 is more feasible compare with BB3.

The prepared magnetic-modified Fe3O4 nanoparticles (Fe3O4-TAN) were used as adsorbent for removal of crystal violet (CV) from water solution. The effects of pH, contact time, dye concentration and temperature on adsorption were determined. The experimental data were analyzed using the Langmuir adsorption model. The data fitted well to the model with maximum adsorption capacities 84.0 mg/gunder pH=11.0. Also the adsorption kinetics and thermodynamic parameters were studied and evaluated. Adsorption of the CV to nanoparticles reached equilibrium after 15 min. In addition, the external magnetic field could easily separate nanoparticles from water with high separation efficiency.

Synthesis of imidazo [1, 2-a] pyridines over several solid supported catalysts has been investigated. Among these catalysts, ZnCl2.SiO2 (silzic) showed excellent yields and short reaction times. The silzic catalyst could be recovered and reused in five reaction cycles. The present procedure offers several advantages such as short reaction time, simplicity of the reaction procedure, the elimination of solvents, simple workup, recovery and reusability of the catalyst.

The quantum-chemical calculations on the conformational properties of 2-flouro-2-oxo- 1, 3, 2-dioxaphosphorinane (1), 2-choloro-2-oxo-1, 3, 2-dioxaphosphorinane (2) and 2-bromo- 2-oxo-1, 3, 2-dioxaphosphorinane (3) have been investigated by means of ab initio molecular orbital (HF/6-311+G**) and hybrid density functional theory (B3LYP/6-311+G**) based methods and Natural Bond Orbital (NBO) interpretation in solid state was performed. Geometrical analysis supports clearly the participation of hyperconjugative endo-anomeric (LPO®s*P-X) effect in the stabilization of axial series of compounds and the participation of exo-anomeric (LPX®s*P-O) effect in the stabilization of the equatorial phosphinanes in chair conformations. The stereoelectronic effects associated with bonding-anticoding delocalization electron are more significant for the explanation of the conformational behavior of compounds 1-3 than the dipole-dipole interaction effects.

Condensation reaction of chalcones with malononitrile and ammonium acetate in the presence of the green nano-modified SBA-15 affords the corresponding 2-amino-3-cyanopyridine derivatives in excellent yield. This approaches claimed to be an environment friendly protocol as it afforded some advantages such as excellent yields and cleaner reaction.

Different biological methods are gaining recognition for the production of silver nanoparticles (Ag-NPs) due to their multiple applications. The use of plants in the synthesis of nanoparticles emerges as a cost effective and eco-friendly approach. In the present study, the synthesis of silver nanoparticles by using Ziziphora tenuior L of water extraction was carried out. For this purpose the water extract of Ziziphora tenuior L is used as the reducing agent. By addition of silver nitrate to this extract at room temperature, the color of the extract changed from pale yellow to dark brown, which showed the formation of silver nanoparticles. The characteristics of the obtained silver nanoparticles were studied using different methods, which including; ultraviolet-visible spectroscopy (UV-Vis), powder X-ray diffraction (XRD), scanning electron microscopy (SEM). Ziziphora tenuior L was found to display strong potential for the synthesis of silver nanoparticles by rapid reduction of silver ions (Ag+to Ago).

7-Hydroxycoumarine undergoes a smooth reaction with alkyl propiolates in the presence of triphenylphosphine (15 mol%) to produce the corresponding alkyl (E) -3- ((2-oxo-2H-chromen- 7-yl) oxy) acrylate in good yields. When the reaction was performed by 3-hydroxyquinoline similar alkyl acrylates were obtained.