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131.
Abdolali Alizadeh Sadegh Rostamnia Nasrin Zohreh Hamid Reza Bijanzadeh 《Monatshefte für Chemie / Chemical Monthly》2008,139(1):49-52
Summary. The three-component reaction of the zwitterions generated from dialkyl acetylenedicarboxylate and isocyanides with isocyanates
is described. The reaction afforded the corresponding special type of ethylenetetracarboxylic acid derivatives in good yields. 相似文献
132.
Firouz Matloubi Moghaddam Mostafa Kiamehr Zohreh Mirjafary Hamdollah Saeidian 《Tetrahedron》2010,66(45):8615-8622
An efficient catalyst-free synthesis of novel pentacyclic thiochromone-annulated thiopyranocoumarin derivatives is achieved via domino Knoevenagel-hetero-Diels-Alder reaction of 4-hydroxy dithiocoumarin and O-acrylated salicylaldehyde derivatives in H2O as solvent. The products are formed in good yields with high regio- and stereo-selectivity. 相似文献
133.
Janet Soleimannejad Zohreh Derikvand Farzaneh Koleiae 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(6):613-616
A three‐dimensional coordination polymer of SrII based on dipicolinic acid (pydcH2) has been synthesized and characterized, namely poly[[diaquabis(μ3‐6‐carboxypyridine‐2‐carboxylato)bis(μ4‐pyridine‐2,6‐dicarboxylato)tristrontium(II)] dihydrate], {[Sr3(C7H3NO4)2(C7H4NO4)2(H2O)2]·2H2O}n. The asymmetric unit consists of two unique SrII centres (one of them situated on an inversion centre), two independent pydc2− ligands, and one coordinated and one uncoordinated water molecule. The two independent SrII cations are surrounded by water and dipicolinate molecules in distorted square‐antiprism and distorted tricapped trigonal prismatic geometries. The dipicolinate ligands adopt μ3‐ and μ4‐bridging modes, linking the alkaline earth metal centres into a three‐dimensional coordination framework. One dipicolinate ligand is doubly deprotonated, while the other is singly deprotonated. 相似文献
134.
A new one-pot synthesis of hitherto unknown polyheterocyclic systems via tandem C-alkylation and intramolecular O-alkylation of 4-hydroxycoumarin or 4-hydroxypyran-2-one with quinolinium salts in excellent yields (71-89%) is reported. The present approach provides a powerful route into polycyclic structures containing nitrogen and oxygen related to alkaloids. 相似文献
135.
A survey of literature reveals that the use of Pitzer approach for modeling electrolyte in nonaqueous or in mixed solvent media is still very scarce. Moreover, only two research groups have used the exact and complete form of the more refined Pitzer–Simonson–Clegg (PSC) ion-interaction approach for the investigation of electrolyte in mixed solvent systems. 相似文献
136.
137.
The main aim of this paper is to propose two semi-implicit Fourier pseudospectral schemes for the solution of generalized time fractional Burgers type equations, with an analysis of consistency, stability, and convergence. Under some assumptions, the unconditional stability of the schemes is shown. In implementation of these schemes, the fast Fourier transform (FFT) can be used efficiently to improve the computational cost. Various test problems are included to illustrate the results that we have obtained regarding the proposed schemes. The results of numerical experiments are compared with analytical solutions and other existing methods in the literature to show the efficiency of proposed schemes in both accuracy and CPU time. As numerical solution of fractional stochastic nonlinear partial differential equations driven by Brownian motions are among current related research interests, we report the performance of these schemes on stochastic time fractional Burgers equation as well. 相似文献
138.
139.
Gallium-68 (T
1/2 = 68 min, I
β+ = 89%) is an important positron-emitting radionuclide for positron emission tomography and used in nuclear medicine for diagnosing
tumours. This study gives a suitable reaction to produce 68Ga. Gallium-68 excitation function via 68Zn(p, n)68Ga, 68Zn(d, 2n)68Ga, 70Zn(p, 3n)68Ga and 65Cu(α, n)68Ga reactions were calculated by ALICE-91 and TALYS-1.0 codes. The calculated excitation function of 68Zn(p, n)68Ga reaction was compared with the reported measurement and evaluations. Requisite thickness of the targets was obtained by
SRIM code for each reaction. The 68Ga production yield was evaluated using excitation function and stopping power.
相似文献
140.
Somayeh Soleimani‐Amiri Faezeh Shafaei Ali Varasteh Moradi Fathali Gholami‐Orimi Zohreh Rostami 《Journal of heterocyclic chemistry》2019,56(10):2744-2752
In this research, green procedure was employed for biosynthesis of magnetic nanoparticles of iron oxide (Fe3O4‐MNPs) by reduction of ferric chloride solution with Orange peel water extract. Also, dihydro‐2H‐cyclopenta[d][1,3]oxazole was generated through multicomponent reaction of 1,3‐oxazole‐2(3H)‐thione, dialkyl acetylenedicarboxylates, α‐haloketones, and Fe3O4‐MNPs as catalyst at ambient temperature in good yield. Initially, 1,3‐oxazole‐2(3H)‐thione derivatives as one of the precursors are produced through the reaction of alkyl bromides, isothiocyanate, sodium hydride, and Fe3O4‐MNPs as catalyst water at ambient temperature in 83–95% yields. Also, diphenyl‐picrylhydrazine radical trapping and ferric reduction activity potential assays are used for evaluation of antioxidant activity of some synthesized compounds. Among investigated compounds, 4b has good power for radical trapping activity and 4d has good reduction power to butylated hydroxytoluene and 2‐tert‐butylhydroquinone. 相似文献