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101.
Friedländer synthesis of 2-acylquinolines from the reaction of symmetrical and unsymmetrical 1,2-diketones with 2-aminoarylketones in the presence of indium triflate (In(OTf)3) and ionic liquid gives quantitative yields. Once the reaction was completed, the catalysts can be recovered and subsequently run for next cycles. Results obtained from theoretical studies have been more strengthened by FT-IR, FT-NMR chemical shifts, and structural parameters which were attained with B3LYP/6-31G(d,p) level of theory and the related results were demonstrated with the experimental interpretations. 相似文献
102.
Ethoxy-4-nitrobenzene was synthesized by the reaction of 4-chloronitrobenzene with potassium ethoxide in a homogeneous system using benzyltriethylammonium chloride (QCl) as a phase-transfer catalyst at 50 degrees C under ultrasound irradiation conditions. The use of phase-transfer catalysts and ultrasound has been compared and demonstrated in this nucleophilic substitution reactions. The kinetics of the reaction depends on the effect of amount of catalyst, quaternary ammonium salts, agitation speed, amount of potassium hydroxide, amount of ethanol, temperature and the frequency of the ultrasound waves on the conversion of the reaction. 相似文献
103.
Ruthenium‐Catalyzed Oxidant‐Free Allylation of Aromatic Ketoximes with Allylic Acetates at Room Temperature
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Rajendran Manikandan Padmaja Madasamy Dr. Masilamani Jeganmohan 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(40):13934-13938
Substituted aromatic ketoximes reacted efficiently with allylic acetates in the presence of {[RuCl2(p‐cymene)]2} and AgSbF6 in 1,2‐dichloroethane at ambient temperature, providing ortho‐allyl aromatic ketoximes in a highly regioselective manner without an oxidant. In the reaction, the acetate group of allyl acetate acts as a base to activate the C?H bond of aromatics. Later, ortho‐allyl aromatic ketoximes were converted into ortho‐allyl aromatic ketones in the presence of HCl. 相似文献
104.
Khan I Sangwan PL Abdullah ST Gupta BD Dhar JK Manickavasagar R Koul S 《Journal of separation science》2011,34(7):749-760
High-performance thin layer chromatography (HPTLC) method for the separation and quantitative determination of ten markers (catechins, flavonoids, and phenolics) in different extracts of green tea and guava leaf has been developed and the antioxidant activity profiles of the two plant extracts have been determined. Ten marker compounds have been resolved using silica gel 60 F(254) plates, toluene/acetone/formic acid (5:4:1 v/v/v) for markers 1-6, and toluene/ethyl acetate/formic acid/methanol (3:3:0.8:0.2 v/v/v/v) for markers 7-10 as the mobile phases. The high-performance thin layer chromatography densitometry was performed at wavelengths of 282 and 285 nm for the markers 1-6 and 7-10, respectively. Potent antioxidant activity and the presence of phenolics and flavan-3-ols has been observed for the guava leaf extracts suggestive of its use as an alternate economical source of antioxidants over green tea--the well-established food additive/nutraceutical agent. 相似文献
105.
The non-steady-state concentration for an EC reaction at planar electrode is derived. The analytical expression for the concentration for EC reaction is reported for small and large value of reaction rate. The asymptotic expression for the non-steady-state current for EC reaction is also derived. The analytical solutions for normalized current response were formulated using the method of Laplace transformation. The concentration and current are compared with available limiting case results, and are found to be in good agreement. 相似文献
106.
G. Rahamathunissa P. Manisankar L. Rajendran K. Venugopal 《Journal of mathematical chemistry》2011,49(2):457-474
A mathematical model of steady state mono-layer potentiometric biosensor is developed. The model is based on non stationary
diffusion equations containing a non linear term related to Michaelis-Menten kinetics of the enzymatic reaction. This paper
presents a complex numerical method (He’s variational iteration method) to solve the non-linear differential equations that
describe the diffusion coupled with a Michaelis-Menten kinetics law. Approximate analytical expressions for substrate concentration
and corresponding current response have been derived for all values of saturation parameter α and reaction diffusion parameter
K using variational iteration method. These results are compared with available limiting case results and are found to be in
good agreement. The obtained results are valid for the whole solution domain. 相似文献
107.
Nanocrystalline cubic fluorite/bixbyite CeO2 or α–Mn2O3 has been successfully synthesized by using methanol as a solvent via sol–gel method calcined at 400 °C. The obtained products
were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy
(SEM), Transmission electron microscopy (TEM), UV–vis absorption and Photoluminescence (PL) spectroscopy. TEM reveals that
the as-synthesized ultra-fine samples consist of elliptical/spherical and sheet-like morphology of crystalline particles of
8/30 nm, which are weakly aggregated. Optical absorbance spectra reveal that the absorption of ceria in the UV region originates
from the charge- transfer transition between the O2− (2p) and Ce4+ (4f) orbit in CeO2. However, α–Mn2O3 nanostructures with nearly pure band gap emission should be of importance for their applications as UV emitters. 相似文献
108.
Suresh R Muthusubramanian S Senthilkumaran R Manickam G 《The Journal of organic chemistry》2012,77(3):1468-1476
The synthesis of 2-(1H-pyrrolo[2,3-b]pyridin-3-yl)quinolines by a SnCl(2)-catalyzed multicomponent reaction has been described. The reaction proceeds chemo- and regioselectively in an atom-economic way, generating a library of 24 quinoline derivatives. 相似文献
109.
The asymptotic distribution of the largest eigenvalue of various classes of random matrices has been shown to have the Tracy–Widom distribution. In this article, we prove that the standardised maximum of an independent and identically distributed sequence of random variables having the Tracy–Widom distribution arising from the Gaussian unitary ensemble belongs to the Gumbel domain of attraction. 相似文献
110.
The present study involves the analysis of surface nanostructures and its variation present in the hind wing of dragon fly (Sympetrum vulgatum) using atomic force microscopy (AFM). The hindwing was dissected into 4 parts (D1-D4) and each dissected section was analyzed using AFM in tapping mode at different locations. The AFM analysis revealed the presence of irregular shaped nanostructures on the surface of the wing membrane with size varying between 83.25±1.79 nm to 195.08±10.25 nm. The size and shape of the nanostructure varied from tip (pterostigma) to the costa part. The membrane surface of the wing showed stacked arrangement leading to increase in size of the nanostructure. Such arrangement of the nanostructures has lead to the formation of nanometer sized valleys of different depth and length on the membrane surface giving them ripple wave morphology. The average roughness of the surface nanostructures varied from 18.58±3.12 nm to 24.25±8.33 nm. Surfaces of the wings had positive skewness in D1, D2 and D4 regions and negative skewness in D3 region. These surface nanostructures may contribute asymmetric resistance under mechanical loading during the flight by increasing the bending and torsional resistance of the wing. 相似文献