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41.
42.
Masoumeh Zakeri Mohamed Mahmoud Nasef Tina Kargaran Arshad Ahmad Ebrahim Abouzari-Lotf Jahanbakhsh Asadi 《Research on Chemical Intermediates》2017,43(2):717-728
Optimization of a green approach to the synthesis of pyrano[2,3-c]pyrazoles based on the one-pot, four-component condensation via a domino Knoevenagel/Michael/cyclization sequence was investigated. This method involved the evaluation of the activity of several ionic liquids (ILs) in various solvents. This one-pot, four-component reaction revealed simplicity, higher yield and lower toxicity advantages over a corresponding three-component method. The effect of reaction parameters including the type and amount of catalyst, type of solvent, reaction temperature and time were studied with respect to yield of pyrano[2,3-c]pyrazoles. Catalyst recyclability and time-saving aspects of the reaction suggest that this method presents real alternatives over conventional reaction protocols. 相似文献
43.
The main goal of this article is to the present research on the development of ketamine derivatives. The target molecule was a fluoroderivative of ketamine, for which a multistep synthesis has been reported. This novel ketamine derivative, 2-(2-fluorophenyl)-2-methylamino-cyclohexanone, has been called fluoroketamine by our research group. The starting fluorobenzonitrile was reacted with the appropriate Grignard reagent followed by the bromination reaction to obtain α-bromocyclopentyl-(2-fluorophenyl)-ketone. The reaction of the obtained ketone with methylamine at ?40 °C then resulted in the formation of α-hydroxycyclopentyl-(2-flourophenyl)-N-methylamine. Finally, the five-memberd ring cyclopentanol was expanded to the cyclohexylketone by a thermal rearrangement reaction. The HCl salt of the target molecule, which is soluble in water, was obtained by the acidification of the free fluoroketamine with HCl. Preliminary animal tests on mice have shown that the resulting fluoroketamine has some advantages over ketamine in terms of the effective dose and the recovery time. 相似文献
44.
In the present work, dispersive liquid-liquid microextraction based on solidification of floating organic drop was developed as a simple and rapid technique for separation of silver ions from aqueous samples. In this technique, 700 μL 0.02% of 5-(4'-dimethylamino benzyliden)-rhodanine (chelating agent) was added into the 10 mL analyte sample in a test tube and 30.0 μL 1-undecanol (extraction solvent) was injected shortly thereafter. The test tubes were sonicated, centrifuged and then some effective parameters on extraction and complex formation, such as type and volume of extraction and disperser solvent, pH, the amount of chelating agent and extraction time were optimized. The effect of the interfering ions on the analytes recovery was also investigated. The calibration graph was linear in the range of 0.10-10.0 ng mL(-1) with detection limit of 0.056 ng mL(-1) (n=8). The relative standard deviation (RSD) was ±4.3% (n=8, C=5.0 ng mL(-1)) and the enrichment factor was 250.0. The proposed method was applied for extraction and determination of silver in different water samples. 相似文献
45.
In this research,a lucunary Keggin structure,[PMo2W9O39]7- was selected as an efficient homogenous catalyst for degradation of an azo dye(direct blue 71) and a simple method was developed for degradation of DB71.The method is based on the oxidation of azo dye in the presence of a lucunary Keggin form of polyoxometalates,K7[PMo2W9O39]? 19H2O,as a homogenous catalyst at room temperature.The reaction is monitored spectrophotometrically by measuring the absorbance of dye atλ=585 nm.Some parameters including concentration of catalyst,concentration of H2O2,pH and reaction time were investigated and optimized. Results show that K7[PMo2W9O39]? 19H2O is more efficient in the presence of hydrogen peroxide.Degradation of dye in the presence of the catalyst and H2O2 could lead to the disappearance approximately 65%of dye after 60 min.But degradation for the same experiment performed in the absence of catalyst or in the absence of H2O2 was 22%or 5%respectively.Approximately 87% azo dyes has been eliminated after 90 min in the presence of catalyst,H2O2 and optimize conditions(0.6 g/L of K7[PMo2- W9O39H9H2O,0.08 mol/L hydrogen peroxide and room temperature). 相似文献
46.
H. Tabaei M. A. Moghimi A. Kimiaeifar M. A. Moghimi 《Journal of Applied Mechanics and Technical Physics》2011,52(4):624-636
This paper presents an analytical solution of the problem of free-convective magnetohydrodynamic flow over a stretched sheet
with the Hall effect and mass transfer taken into account. A similarity transform reduces the Navier-Stokes, energy, Ohm law,
and mass-transfer equations to a system of nonlinear ordinary differential equations. The governing equations are solved analytically
using an analytical method for solving nonlinear problems, namely, the homotopy analysis method. The results are compared
with the results of a promising numerical method of differential quadrature developed by the authors. It is shown that there
is very good agreement between analytical results and those obtained by the differential quadrature method. The differential
quadrature method was validated, and the effects of non-dimensional parameters on the velocity, temperature and concentration
profiles were studied. 相似文献
47.
Majid M. Heravi Fatemeh Derikvand Masoumeh Haghighi 《Monatshefte für Chemie / Chemical Monthly》2008,139(1):31-33
Summary. An efficient and improved procedure for the synthesis of tetrasubstituted imidazoles by FeCl3 · 6H2O catalyzed four-component one-pot synthesis in refluxing ethanol is described. 相似文献
48.
Mehdi M. Baradarani Bahman Ebrahimi Saatluo Shiva Ghabeli Zahra Shokri Masoumeh Shahbazi John A. Joule 《Journal of heterocyclic chemistry》2019,56(7):1999-2007
The tricyclic isatin, 5,6‐dihydro‐4H‐pyrrolo[3,2,1‐ij]quinoline‐1,2‐dione, undergoes three‐component, one‐pot reactions with 1‐aryl‐3‐methylpyrazole‐5‐amines and cyclohexane‐1,3‐diones producing hexacyclic spiro products, hexahydrospiro[pyrazolo[3,4‐b]quinoline‐4,1‐pyrrolo[3,2,1‐ij]quinoline‐2′,5(1H,4′H)‐diones]. Comparable spiro condensation products are also obtained using 4‐hydroxy‐2H‐1‐benzopyran‐2‐one in place of cyclohexane‐1,3‐diones. 相似文献
49.
Tamoradi Taiebeh Navaee Aso Salimi Abdollah Mousavi Seyedeh Masoumeh Ghadermazi Mohammad Veisi Hojat 《Research on Chemical Intermediates》2019,45(9):4517-4530
Research on Chemical Intermediates - Heterogeneous catalysts are more prominent rather than homogenous catalysts since they are simply separated from products. To improve and develop heterogeneous... 相似文献
50.
Acoustic performance of dissipative silencer was evaluated to determine the effectiveness of perforated duct porosity and absorbent material density in reducing occupational noise exposure propagated from centrifugal fan. Design charts were applied to predict noise reduction and length of a dissipative silencer. Dissipative silencers with various punched duct porosity (14%, 30% and 40%) and sound absorbent density (80 Kg/m3, 120 Kg/m3, and 140 Kg/m3) were designed and fabricated. According to ISO9612 and ISO11820, noise level was measured before and after installing all nine test silencers at fixed workstations around the discharge side of a centrifugal fan in a manufacturing plant. On average, the noise level at the discharge side of a fan without silencer was measured to be 93.6 dBA, whereas it was significantly mitigated by 67.4 dBA to 70.1 dBA after installing all silencers. Dynamic insertion loss for a dissipative silencer with 100 cm length was predicted to be 27.9 dB, which was in agreement with experimental ones. Although, there was no significant differences between insertion loss of silencers, the one with 30% porosity and 120 Kg/m3 rock wool density had the highest insertion loss of 26.2 dBA. Dissipative silencers noticeably reduced centrifugal fan noise exposures. Increasing sound absorbent density and duct porosity up to a certain limit could probably be effective in noise reduction of dissipative silencers. 相似文献