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Katkar Santosh Shriram Lande Machhindra Karbhari Arbad Balasaheb Ramrao Gaikwad Suresh Tukaram 《中国化学》2011,29(1):199-202
4H‐Benzo[b]pyrans was synthesized under reflux condition in ethanol via condensation of benzaldehyde, malononitrile and dimedone with ZnO‐beta zeolite as an inexpensive and effective catalyst. The key features of the reported protocols are good to excellent yields, short reaction time and recovery and reusability of catalytic material. 相似文献
243.
Suresh E. Kurhade Sudhir RavulaV. Siddaiah Debnath BhuniyaD. Srinivasa Reddy 《Tetrahedron letters》2011,52(33):4313-4315
A convenient one-step method for the synthesis of novel dihydrooxazine and oxazoline based sugar hybrids is reported starting from the readily accessible sugar azides and aldehydes. We have used Aubé’s protocol to achieve this transformation. The resulting glycoconjugates could be used to increase the diversity on the sugar backbone and may find applications as potential glycomimetics and in drug discovery. 相似文献
244.
P. S. Suresh Sanjeev Giri Raghib Husain Ramesh Mullangi 《Biomedical chromatography : BMC》2010,24(10):1052-1058
A highly sensitive, rapid assay method has been developed and validated for the estimation of S‐citalopram (S‐CPM) in rat plasma with liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the positive‐ion mode. The assay procedure involves a simple liquid–liquid extraction of S‐CPM and phenacetin (internal standard, IS) from rat plasma with t‐butyl methyl ether. Chromatographic separation was operated with 0.2% formic acid:acetonitrile (20:80, v/v) at a flow rate of 0.50 mL/min on a Symmetry Shield RP18 column with a total run time of 3.0 min. The MS/MS ion transitions monitored were 325.26 → 109.10 for S‐CPM and 180.10 → 110.10 for IS. Method validation and pre‐clinical sample analysis were performed as per FDA guidelines and the results met the acceptance criteria. The lower limit of quantitation achieved was 0.5 ng/mL and the linearity was observed from 0.5 to 5000 ng/mL. The intra‐ and inter‐day precisions were in the range of 1.14–5.56 and 0.25–12.3%, respectively. This novel method has been applied to a pharmacokinetic study and to estimate brain‐to‐plasma ratio of S‐CPM in rats. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
245.
Mariappan Periasamy Subramaniapillai Selva Ganesan Surisetti Suresh 《Tetrahedron: Asymmetry》2010,21(4):385-392
β-Amino esters were obtained in up to 78% yield with 72:28–96:4 diastereomeric ratios by the reaction of the chiral titanium enolate of menthyl esters, prepared using the TiCl4/Et3N reagent system with prochiral imines. A representative syn-β-amino ester derivative has been used for the resolution of racemic mandelic acid to obtain a sample with >99% ee in a single step. A representative syn-β-amino ester was converted to the corresponding N-deprotected amino ester using the Pd–C/HCOOH reagent system, and then to the corresponding β-amino acid using the glacial CH3COOH/HCl reagent system, and to the corresponding β-lactam derivative with partial epimerization by the reaction using C2H5MgBr. 相似文献
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Ch. S. Y. Suresh Y. Vamsee Krishna T. Sundararajan Sarit K. Das 《Heat and Mass Transfer》2005,41(9):799-809
Natural convection in anisotropic heat generating porous medium enclosed inside a rectangular cavity has been studied. A 3D finite volume based code is developed using the Darcy approximation and validated using experimental results of natural convection around an enclosed rod bundle. Subsequently, detailed simulation is carried out for a cavity, filled with orthotropic porous medium. The effects of heat generation, geometry and anisotropy are studied. Anisotropy is found to be of significant importance for both maximum value and distribution of temperature. 相似文献
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A theory of rolling horizon decision making 总被引:1,自引:0,他引:1
In this paper, we develop a theoretical framework for the common business practice of rolling horizon decision making. The main idea of our approach is that the usefulness of rolling horizon methods is, to a great extent, implied by the fact that forecasting the future is a costly activity. We, therefore, consider a general, discrete-time, stochastic dynamic optimization problem in which the decision maker has the possibility to obtain information on the uncertain future at given cost. For this non-standard optimization problem with optimal stopping decisions, we develop a dynamic programming formulation. We treat both finite and infinite horizon cases. We also provide a careful interpretation of the dynamic programming equations and illustrate our results by a simple numerical example. Various generalizations are shown to be captured by straightforward modifications of our model.This research is supported in part by NSERC Grant A4619, SSHRC Grant 410-87-0524, and Manufacturing Research Corporation of Ontario. Comments and suggestions from Qing Zhang and the referees are gratefully acknowledged. 相似文献